Nano particle colloid ink, nano particle single-layer film and preparation method and application of nano particle colloid ink and nano particle single-layer film

Abstract

The invention discloses nano-particle colloid ink, a nano-particle single-layer film and a preparation method and application of the nano-particle colloid ink and the nano-particle single-layer film, and belongs to the technical field of nano-materials. The nanoparticle colloid ink comprises sulfydryl-terminated polymer grafted core-shell nanoparticles, a free polymer and an ink solvent with the boiling point higher than 150 DEG C, wherein the solubility parameter difference between the free polymer and the sulfydryl-terminated polymer is smaller than 2. According to the nanoparticle colloid ink, the particle spacing of a nanoparticle single-layer film can be adjusted through the concentration of the free polymer, the nanoparticle colloid ink is expected to be used for simple preparation of a multi-stage patterned nanoparticle array structure, the coffee ring effect can be fully inhibited, and the orderliness of the prepared nanoparticle single-layer film is effectively improved; and the mechanical property and the dielectric property of the prepared nanoparticle single-layer film can be effectively improved, so that the single-layer film can be desorbed from a solid substrate and transferred to a flexible substrate, and the preparation method is suitable for preparing a flexible memory with high capacity, high stability and low power consumption.

Description

Technical Field

[0001] The present application belongs to the technical field of nanomaterials, and in particular relates to a nanoparticle colloid ink, a nanoparticle monolayer film, and a preparation method and application thereof. Background Art

[0002] One of the keys to high-performance nano-floating gate memory is to prepare a highly ordered, large-area metal nanoparticle monolayer with adjustable interparticle spacing. However, the traditional nano-micelle solution dip coating / spin coating technology is commonly used to prepare highly densely arranged nanoparticle monolayers. While the film area is small, it is not easy to accurately control the interparticle spacing, which limits the development of nano-floating gate memory. Therefore, the design and preparation of metal nanoparticle monolayers with adjustable interparticle spacing has become a research hotspot.

[0003] At present, the related field discloses that colloidal ink with polymer grafted inorganic nanoparticles as solute can be used to construct nanoparticle monolayer films with adjustable interparticle spacing. For example, a method for constructing ordered nanoparticle monolayer films by inkjet printing disclosed in publication number CN114231091A uses optimized colloidal ink with polymer grafted inorganic nanoparticles as solute for inkjet printing to prepare highly ordered centimeter-level nanoparticle monolayer films with adjustable interparticle spacing, which is expected to meet the needs of nano floating gate memory.

[0004] However, there are still some shortcomings when using the optimized colloidal ink to print the nanoparticle monolayer film. For example, the adjustment of its interparticle spacing is highly dependent on the design of the molecular weight of the polymer ligand, which leads to the need to first prepare multi-level molecular weight polymer grafted nanoparticles when preparing the patterned nanoparticle array. The process is cumbersome and complex, and the cost is high, which is not suitable for the preparation of multi-level patterned nanoparticle arrays. In addition, the mechanical properties of the prepared nanoparticle monolayer film are poor. When used on a flexible substrate, it is easily broken and split by external forces, which limits its application in flexible substrate devices. Summary of the invention

[0005] The present application discloses a nanoparticle colloidal ink, a nanoparticle monolayer film, and a preparation method and application thereof, which effectively solve the technical problems of cumbersome and complex procedures and high costs when the existing optimized colloidal ink is used to prepare a patterned nanoparticle array structure.

[0006] In order to achieve the above objectives, the technical solution adopted in this application is:

[0007] The first aspect of the present application provides a nanoparticle colloidal ink, the composition of which includes the following solute components and an ink solvent with a boiling point higher than 150° C.:

[0008] (a) Thiol-terminated polymer-grafted core-shell nanoparticles;

[0009] (b) a free polymer having a solubility parameter that differs from that of the thiol-terminated polymer by less than 2.

[0010] In a preferred embodiment, the thiol-terminated polymer is one of a thiol-terminated polystyrene homopolymer, a thiol-terminated polyepoxy homopolymer, and a thiol-terminated polyacrylate homopolymer; and,

[0011] The free polymer is one of polystyrene homopolymer, polyepoxy homopolymer and polyacrylate homopolymer.

[0012] In a preferred embodiment, the nanoparticle core constituting the thiol-terminated polymer-grafted core-shell nanoparticles is one of metal nanoparticles, metal oxide nanoparticles, and SiO2 nanoparticles.

[0013] In a preferred embodiment, the metal nanoparticles are gold nanoparticles, silver nanoparticles and combinations thereof.

[0014] In a preferred embodiment, the metal oxide nanoparticles are ZnO2 nanoparticles, Fe3O4 nanoparticles and combinations thereof.

[0015] In a preferred embodiment, the shape of the nanoparticle core is one of sphere, cube and polyhedron, wherein the diameter of the spherical nanoparticle core is 5-50 nm.

[0016] In a preferred embodiment, the dispersed concentration of the solute component is:

[0017] (a) Thiol-terminated polymer-grafted core-shell nanoparticles 20-80 mg / mL;

[0018] (b) Free polymer 1-10 mg / mL.

[0019] In a preferred embodiment, the ink solvent is one of butylbenzene, dimethyl adipate, diphenyl ether and cyclooctanone.

[0020] In a preferred embodiment, the molecular weight of the free polymer is 2000-5000 g / mol, and the molecular weight of the thiol-terminated polymer is 2000-50000 g / mol.

[0021] The second aspect of the present application provides a nanoparticle monolayer film, which comprises a nanoparticle array formed by printing using the nanoparticle colloidal ink described in the present application.

[0022] The third aspect of the present application provides a method for preparing the nanoparticle monolayer film of the present application, the steps of which include:

[0023] Setting the nanoparticle array;

[0024] Using the nanoparticle colloid ink to print on the surface of a substrate to construct the nanoparticle array, followed by solvent annealing and water immersion desorption;

[0025] Wherein, the printing and constructing of the nanoparticle array comprises:

[0026] The concentration of the free polymer contained in the nanoparticle colloid ink is adjusted to adjust the interparticle distance of the nanoparticle array.

[0027] The fourth aspect of the present application provides the use of the nanoparticle monolayer film described in the present application for preparing nano floating gate memory, surface Raman enhanced substrate, and solar cell.

[0028] Compared with the prior art, the advantages or beneficial effects of the present application include at least:

[0029] When studying optimized colloidal inks with polymer-grafted nanoparticles as solutes, the present application unexpectedly discovered that by adding free polymers with similar solubility to the optimized colloidal inks and setting a composite ratio and solvent, the interparticle spacing of the nanoparticle monolayer film can be precisely adjusted by adjusting the concentration of the free polymers. When printing patterned nanoparticle arrays, it is no longer necessary to prepare multi-level molecular weight polymer-grafted nanoparticles, which greatly simplifies the preparation process and reduces costs, and is expected to achieve simple and efficient preparation of multi-level patterned nanoparticle array structures. At the same time, the free polymer can produce polymer molecular chain entanglement and intermolecular interaction with the polymer-grafted nanoparticles, which can increase the viscosity of the ink and reduce its surface tension. At the same time, it can be enriched on the gas-liquid interface surface when the solvent evaporates to form a physical barrier that can slow down the evaporation of the solvent. Multi-level synergy can further improve the rheological properties of the colloidal ink, fully inhibit the coffee ring effect, make the colloidal ink more evenly deposited, effectively improve the orderliness of the prepared nanoparticle monolayer film, and can effectively improve the mechanical properties and dielectric properties of the prepared nanoparticle monolayer film, so that the prepared monolayer film can be quickly desorbed from the solid substrate by water immersion, and has the potential to be used in the preparation of flexible memory, and is expected to achieve the preparation of large-capacity, high-stability, and low-power flexible memory. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 DIW-Au@PS provided for this application 5k -SH / PS 2K Optical photograph of / Si;

[0032] Figure 2 DIW-Au@PS provided for this application 5k -SH / PS 2K / Atomic force micrograph of Si;

[0033] Figure 3 DIW-Au@PS provided for this application 5k -SH / PS 2K / SEM image of Si;

[0034] Figure 4 DIW-Au@PS provided for this application 5k -SH / PS 2K / Si is prepared into a memory device and then tested after the transistor transfer curve, output curve and storage window test curve;

[0035] Figure 5 DIW-Au@PS provided for this application 5k -SH / PS 2K / Si is prepared into a memory device and tested for read-write-erase-programming curve and maintenance time curve;

[0036] Figure 6 Kelvin probe microscope surface potential image of the nanoparticle monolayer film prepared in Examples 2-4 provided in this application;

[0037] Figure 7 The scanning electron microscope image of the colloidal nanoparticle monolayer composite film prepared in Examples 2-4 provided in the present application;

[0038] Figure 8 DIW-Au@PS provided for this application 12k -SH / PS 2K -C1 and DIW-Au@PS 12k -Optical photograph of SH;

[0039] Fig. 9 DIW-Au@PS provided for this application 12k -SH / PS 2K -Optical and scanning electron microscope images of C1 / PET;

[0040] Fig.10 DIW-Au@PCL provided for this application 4k -SH / PCL 2K and DIW-Au@PMMA 8K -SH / PMMA 2k Scanning electron microscope photos of

[0041] Fig.11SC-Au@PS provided for this application 5k -SH / PS 2K Optical photograph of / Si Scanning electron microscope image;

[0042] Fig.12 DIW-Au@PS provided for this application 5k -SH and DIW-Au@PS 12k -SEM image of SH;

[0043] Fig.13 DIW-Au@PS provided for this application 5k -SH / P4VP 2k / Si、DIW-Au@PS 5k -SH / PC L 2k / Si and DIW-Au@PS 5k -SH / PMMA 2k / Si scanning electron microscope image. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments described in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0045] In the following description of this specification, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. Among them, A and B can be singular or plural; the symbol " / " means "or".

[0046] In the following description of this specification, the term "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of A, B or C", or "at least one of A, B and C" can mean any one of A, B, C, or A+B, or A+C, or B+C, or A+B+C, where A, B, C can be single or multiple, respectively.

[0047] In the following description of this specification, the order of serial numbers does not mean the order of execution. Some or all of the steps can be executed in parallel or one after the other. The execution order of each process should be determined by its function and internal logic, and does not constitute any limitation on the execution process of this embodiment.

[0048] In the following description of this specification, the numerical range should be understood to also specifically disclose each intermediate value between the upper and lower limits of the range. Any stated value or intermediate value in the stated range and any other stated value or each smaller range between the intermediate values ​​in the range are also included in this embodiment, and the upper and lower limits of the smaller range can be independently included or excluded in the range.

[0049] Unless otherwise specified, the technical / scientific terms used in this specification have the meanings commonly understood by those of ordinary skill in the art. Although this specification only describes preferred materials and methods, any similar or equivalent methods and materials may also be used in specific embodiments or test cases. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0050] In a first aspect, the present invention provides a nanoparticle colloid ink. The nanoparticle colloid ink of the present invention comprises the following solute components and an ink solvent having a boiling point higher than 150° C.:

[0051] (a) Thiol-terminated polymer-grafted core-shell nanoparticles;

[0052] (b) a free polymer having a solubility parameter that differs from that of the thiol-terminated polymer by less than 2.

[0053] The free polymer is a composite solute component dissolved in the solvent in a free form. It can generate polymer molecular chain entanglement and intermolecular interaction with the polymer grafted nanoparticles, which increases the viscosity of the ink and reduces its surface tension. At the same time, it can be enriched on the gas-liquid interface surface during evaporation to form a physical barrier that can slow down the evaporation of the solvent, thereby optimizing and improving the rheological properties of the ink, effectively limiting the mobility of the solvent molecules and enhancing the Marangoni flow, so that the coffee ring effect is significantly suppressed. The synergistic effect based on these mechanisms not only makes the polymer grafted nanoparticles more uniformly deposited, distributed and orderly assembled during the printing process, but also gives the preparation The highly ordered forming effect of the nanoparticle monolayer film is achieved, and the free polymer increases the diffusion of the polymer-grafted nanoparticles through steric hindrance, so that the effective regulation of the interparticle spacing of the nanoparticle monolayer film can be achieved by adjusting the concentration of the free polymer, which is expected to simplify the preparation of multi-level patterned nanoparticle array structures; in addition, the free polymer can produce a synergistic effect with the thiol-terminated polymer, thereby improving the mechanical properties and dielectric properties of the formed nanoparticle monolayer film, which not only enables the formed nanoparticle monolayer film to be removed from the solid substrate by water immersion and has the potential to be used to prepare flexible memory, but is expected to achieve the preparation of flexible memory with large capacity, high stability and low power consumption.

[0054] It should be noted that the embodiments of the present application do not specifically limit the preparation method of the thiol-terminated polymer grafted core-shell nanoparticles, and the polymer grafted core-shell nanoparticle methods known in the art, such as ligand exchange method, surface-initiated polymerization method and block polymer micelle adsorption reduction method, etc., can be used to prepare core-shell colloidal nanoparticles with a thiol-terminated polymer as the outer shell.

[0055] In summary, the embodiments of the present application provide a combined solute of core-shell nanoparticles grafted with thiol-terminated polymers and free polymers whose solubility difference with the thiol-terminated polymers is less than 2, and reasonably select the concentration ratio of the solvent and the combined solutes. It is thus possible to achieve precise regulation of the interparticle spacing of the nanoparticle monolayer film by adjusting the concentration of the free polymers. When printing patterned nanoparticle arrays, it is no longer necessary to prepare multi-level molecular weight polymer grafted nanoparticles, which greatly simplifies the preparation process and reduces costs, and is expected to achieve simple and efficient preparation of multi-level patterned nanoparticle array structures. At the same time, the free polymer can produce polymer molecular chain entanglement and intermolecular interaction with the polymer-grafted nanoparticles, which can increase the viscosity of the ink and reduce its surface tension. At the same time, it can be enriched on the gas-liquid interface surface when the solvent evaporates to form a physical barrier that can slow down the evaporation of the solvent, thereby fully inhibiting the coffee ring effect by improving the rheological properties of the colloidal ink, making the colloidal ink more evenly deposited, effectively improving the orderliness of the prepared nanoparticle monolayer film, and can effectively improve the mechanical properties and dielectric properties of the prepared nanoparticle monolayer film, so that the prepared monolayer film can be quickly desorbed from the solid substrate by water immersion, and has the potential to be used in the preparation of flexible memory, and is expected to achieve the preparation of large-capacity, high-stability, and low-power flexible memory.

[0056] According to the nanoparticle colloid ink disclosed in the present application, the thiol-terminated polymer is preferably one of a thiol-terminated polystyrene homopolymer, a thiol-terminated polyepoxy homopolymer, and a thiol-terminated polyacrylate homopolymer; and the free polymer is preferably one of a polystyrene homopolymer, a polyepoxy homopolymer, and a polyacrylate homopolymer. For example, when the polystyrene homopolymer is polystyrene (PS), the thiol-terminated polymer may be thiol polystyrene (PS-SH); when the polyepoxy homopolymer is polycaprolactone (PCL), the thiol-terminated polymer may be thiol polycaprolactone (PCL-SH); when the polyacrylate homopolymer is polymethyl methacrylate (PMMA), the thiol-terminated polymer may be thiol polymethyl methacrylate (PMMA-SH).

[0057] It should be noted that the embodiments of the present application select a dielectric polymer with good oil solubility, insulation and the ability to store electrons and holes as a free polymer, and select a thiol-terminated polymer grafted nanoparticles converted from the free polymer, so that the free polymer and the thiol-terminated polymer have similar solubility, effectively avoiding the phase separation problem between different polymer components, and making the nanoparticle colloidal ink have good solubility and dispersibility; and the free polymer and the thiol-terminated polymer with similar molecular structure can produce polymer molecular chain entanglement, effectively improving the mechanical properties and dielectric properties of the prepared nanoparticle monolayer film, so that the prepared nanoparticle monolayer film can be completely desorbed from the solid substrate and transferred to a flexible substrate, which is expected to be used to prepare flexible substrate storage devices, and is expected to achieve the preparation of flexible storage devices with large capacity, high stability and low power consumption.

[0058] According to the nanoparticle colloid ink disclosed in the present application, the nanoparticle core constituting the thiol-terminated polymer-grafted core-shell nanoparticles is one of metal nanoparticles, metal oxide nanoparticles, and SiO2 nanoparticles. The metal nanoparticles may be gold nanoparticles, silver nanoparticles, and combinations thereof; the metal oxide nanoparticles may be ZnO2 nanoparticles, Fe3O4 nanoparticles, and combinations thereof.

[0059] According to the nanoparticle colloidal ink disclosed in the present application, the shape of the nanoparticle core is one of sphere, cube and polyhedron, wherein the diameter of the spherical nanoparticle core is 5-50nm, preferably 5-15nm, such as 5nm, 8nm, 10nm, 15nm, etc.

[0060] According to the nanoparticle colloid ink disclosed in the present application, the dispersion concentration of the solute component is:

[0061] (a) 20-80 mg / mL of thiol-terminated polymer-grafted core-shell nanoparticles, preferably 30-60 mg / mL, such as 30 mg / mL, 40 mg / mL, 43 mg / mL, 46 mg / mL, 50 mg / mL, 60 mg / mL, etc.;

[0062] (b) Free polymer 1-10 mg / mL, preferably 2-6 mg / mL, for example 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, etc.

[0063] It should be noted that the polymer chains grafted on the nanoparticles are in a bent conformation under normal conditions due to thermodynamic energy minimization and entropy maximization. The free polymer added in the present application can penetrate into the shell of the grafted polymer and transform the bent conformation into a straight conformation through spatial compression to achieve the purpose of thickening the polymer shell. Therefore, the present application can not only make the prepared nanoparticle monolayer film have a suitable interparticle distance and film thickness by controlling the concentrations of the thiol-terminated polymer grafted core-shell nanoparticles and the free polymer respectively, but also can give the prepared nanoparticle monolayer film excellent mechanical properties and dielectric properties, thereby ensuring good usability.

[0064] According to the colloidal ink disclosed in the present application, the ink solvent is one of butylbenzene, dimethyl adipate, diphenyl ether, and cyclooctanone. Among them, the listed solvent (boiling point higher than 150°C) has the characteristics of slow volatilization speed and low polarity, which can make the colloidal ink form a good dispersion effect, a suitable volatilization rate and a more suitable spreading property on the substrate (contact angle less than 20°), so that the colloidal ink can shrink the three-phase contact line steadily and orderly during the drying process, which is conducive to promoting the orderly assembly of nanoparticles and finally forming a composite monolayer film with information storage capacity.

[0065] According to the nanoparticle colloid ink disclosed in the present application, the molecular weight of the thiol-terminated polymer is 2000-50000 g / mol, preferably 4000-12000 g / mol, such as 4000 g / mol, 5000 g / mol, 8000 g / mol, 12000 g / mol, etc.; the molecular weight of the free polymer is 2000-5000 g / mol, such as 2000 g / mol, 3000 g / mol, 4000 g / mol, 5000 g / mol, etc. Wherein, for the convenience of recording, each molecular weight is abbreviated as 2k, 3k, 4k, 5k, 8k, 12k, etc.

[0066] It should be noted that the molecular weight of the thiol-terminated polymer determines the thickness of the nanoparticle shell and the dispersibility in the ink solvent, while the molecular weight of the free homopolymer determines whether it can be evenly distributed around the nanoparticle without phase separation. Therefore, the present application can effectively control the particle size of the colloidal nanoparticles and improve the dispersibility and solubility of the colloidal ink by controlling the molecular weight of the polymer ligand and the molecular weight of the free polymer.

[0067] In the second aspect, the embodiments of the present application also provide a nanoparticle monolayer film, which comprises a nanoparticle array formed by printing the nanoparticle colloidal ink described in the above text application. Among them, because the nanoparticle colloidal ink described in the present application has good solubility and rheological properties, the evaporation rate of the ink can be slow and controllable during the drying process, and the coffee ring effect is significantly suppressed. Therefore, the nanoparticle monolayer film of the present application has good ordered molding effect, mechanical properties and dielectric properties, can be quickly desorbed from the solid substrate by water immersion, and has the potential to be used for the preparation of flexible memory, and has a good prospect for the preparation of large-capacity, high-stability, and low-power flexible memory. Among them, the test of the embodiment shows that the nanoparticle array printed by the present application has at least the following characteristics:

[0068] (i) Ordered hexagonal structure;

[0069] (ii) the thickness of the monolayer is 10-100 nm;

[0070] (iii) The area of ​​a single complete membrane is 0.25-10 cm 2 ;

[0071] In a third aspect, the present application also provides a method for preparing the nanoparticle monolayer film of the above application, which comprises:

[0072] Setting the nanoparticle array;

[0073] Using the nanoparticle colloid ink to print on the surface of a substrate to construct the nanoparticle array, followed by solvent annealing and water immersion desorption;

[0074] Wherein, the printing and constructing of the nanoparticle array comprises:

[0075] Adjusting the concentration of free polymer contained in the nanoparticle colloid ink to adjust the interparticle distance of the nanoparticle array;

[0076] The substrate comprises a quartz wafer, an ITO conductive glass or a silicon wafer.

[0077] The fourth aspect of the present application provides the use of the nanoparticle monolayer film described in the present application for preparing nano floating gate memory, surface Raman enhanced substrate, and solar cell.

[0078] The technical solution of the present application will be further described below in conjunction with specific embodiments.

[0079] Example 1

[0080] This example provides a nanoparticle monolayer film (DIW-Au@PS 5k -SH / PS 2K ) direct writing printing forming method, the specific steps are:

[0081] S1: Polystyrene (PS 5k -SH) modified gold nanoparticles (Au NPs) by ligand exchange S , d = 15nm), and then centrifugation and dichloromethane washing were repeated for 5 times, followed by drying to obtain thiol-terminated polystyrene grafted gold nanoparticles (Au@PS 5k -SH);

[0082] S2: Au@PS 5k -SH (50 mg / mL) and PS 2k (4 mg / mL) was dispersed in diphenyl ether to prepare nanoparticle colloidal ink (Au@PS 5k -SH / PS 2K );

[0083] S3: Use a direct-write inkjet printer, set the printer nozzle outlet inner diameter to 50 μm, the printing line spacing to 150 μm, and the printing speed to 10,000 μm / s, and directly write on the cleaned silicon wafer surface. The contact angle between the nanoparticle colloidal ink and the silicon wafer surface is 22°, and a loaded nanoparticle monolayer film precursor is obtained;

[0084] S4: Place the nanoparticle-loaded monolayer film precursor in a vacuum drying oven and perform solvent annealing for 6 h at 80 °C / toluene atmosphere to obtain a nanoparticle-loaded monolayer film (DIW-Au@PS 5k -SH / PS 2K / Si).

[0085] Example 2

[0086] This example provides a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C1) direct writing printing method, the specific steps are:

[0087] S1: Preparation of thiol-terminated polystyrene grafted gold nanoparticles (Au@PS 12k -SH, same as in Example 1);

[0088] S2: Au@PS 12k -SH (46 mg / mL) and PS 2k (2 mg / mL) was dispersed in diphenyl ether to prepare nanoparticle colloidal ink (Au@PS 12k -SH / PS 2K -C1);

[0089] S3: Use a direct-write inkjet printer, set the printer nozzle outlet inner diameter to 50 μm, the printing line spacing to 150 μm, and the printing speed to 10,000 μm / s, and directly write on the cleaned silicon wafer surface. The contact angle between the nanoparticle colloidal ink and the silicon wafer surface is 22°, and the loaded nanoparticle monolayer film precursor-C1 is obtained;

[0090] S4: Place the nanoparticle-loaded monolayer film precursor-C1 in a vacuum drying oven and perform solvent annealing for 6 h at 80°C / toluene atmosphere to obtain a nanoparticle-loaded monolayer film (DIW-Au@PS 12k -SH / PS 2K -C1 / Si);

[0091] S5: DIW-Au@PS 12k -SH / PS 2K -C1 / Si was immersed in deionized water, and the film was desorbed from the silicon wafer and floated on the water surface to obtain a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C1);

[0092] S6: Place the PET substrate horizontally just below the nanoparticle monolayer film in deionized water, and absorb the deionized water to obtain the PET-loaded nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C1 / PET).

[0093] Example 3

[0094] This example provides a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C2) direct writing printing forming method, the specific steps are:

[0095] S1: Preparation of thiol-terminated polystyrene grafted gold nanoparticles (Au@PS 12k -SH, same as in Example 2);

[0096] S2: Au@PS 12k -SH (43 mg / mL) and PS 2k (4 mg / mL) was dispersed in diphenyl ether to prepare nanoparticle colloidal ink (Au@PS 12k -SH / PS 2K -C2);

[0097] S3: Use a direct-write inkjet printer, set the printer nozzle outlet inner diameter to 50 μm, the printing line spacing to 150 μm, and the printing speed to 10,000 μm / s, and directly write and print on the cleaned silicon wafer surface. The contact angle between the nanoparticle colloidal ink and the silicon wafer surface is 22°, and the loaded nanoparticle monolayer film precursor-C2 is obtained;

[0098] S4: Place the nanoparticle-loaded monolayer film precursor-C2 in a vacuum drying oven and anneal for 6 h in a toluene atmosphere at 80°C to obtain a nanoparticle-loaded monolayer film (DIW-Au@PS 12k -SH / PS 2K -C2 / Si);

[0099] S5: DIW-Au@PS 12k -SH / PS 2K -C2 / Si was immersed in deionized water, and the film was desorbed from the silicon wafer and floated on the water surface to obtain a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C2);

[0100] S6: Place the PET substrate horizontally just below the nanoparticle monolayer film in deionized water, and absorb the deionized water to obtain the PET-loaded nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C2 / PET).

[0101] Example 4

[0102] This example provides a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C3) direct writing printing method, the specific steps are:

[0103] S1: Preparation of thiol-terminated polystyrene grafted gold nanoparticles (Au@PS 12k -SH, same as in Example 2);

[0104] S2: Au@PS 12k -SH (40 mg / mL) and PS 2k (6 mg / mL) was dispersed in diphenyl ether to prepare nanoparticle colloidal ink (Au@PS 12k -SH / PS 2K -C3);

[0105] S3: Use a direct-write inkjet printer, set the printer nozzle outlet inner diameter to 50 μm, print line spacing to 150 μm, and print speed to 10,000 μm / s, and directly write on the cleaned silicon wafer surface. The contact angle between the nanoparticle colloid ink and the silicon wafer surface is 22°, and the loaded nanoparticle monolayer film precursor - C3 is obtained;

[0106] S4: Place the nanoparticle-loaded monolayer film precursor-C3 in a vacuum drying oven and anneal for 6 h in a toluene atmosphere at 80°C to obtain a nanoparticle-loaded monolayer film (DIW-Au@PS 12k -SH / PS 2K -C3 / Si);

[0107] S5: DIW-Au@PS 12k -SH / PS 2K -C3 / Si was immersed in deionized water, and the film was desorbed from the silicon wafer and floated on the water surface to obtain a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C3);

[0108] S6: Place the PET substrate horizontally just below the nanoparticle monolayer film in deionized water, and absorb the deionized water to obtain the PET-loaded nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C3 / PET).

[0109] Example 5

[0110] This example provides a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C4) direct writing printing forming method, the specific steps include:

[0111] S1: Preparation of thiol-terminated polystyrene grafted gold nanoparticles (Au@PS 12k -SH, same as Example 2, Au d=8nm);

[0112] S2: Au@PS 12k -SH (30 mg / mL) and PS 2k (3 mg / mL) was dispersed in butylbenzene to prepare nanoparticle colloidal ink (Au@PS 12k -SH / PS 2K -C4);

[0113] S3: Use a direct-write inkjet printer, set the printer nozzle outlet inner diameter to 50 μm, the printing line spacing to 150 μm, and the printing speed to 10,000 μm / s, and directly write on the cleaned silicon wafer surface. The contact angle between the nanoparticle colloidal ink and the silicon wafer surface is 22°, and the loaded nanoparticle monolayer film precursor - C4 is obtained;

[0114] S4: Place the nanoparticle-loaded monolayer film precursor-C4 in a vacuum drying oven and solvent anneal for 6 h at 80°C / toluene atmosphere to obtain a nanoparticle-loaded monolayer film (DIW-Au@PS 12k -SH / PS 2K -C4 / Si);

[0115] S5: DIW-Au@PS 12k -SH / PS 2K -C4 / Si was immersed in deionized water, and the film was desorbed from the silicon wafer and floated on the water surface to obtain a nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C4);

[0116] S6: Place the PET substrate horizontally just below the nanoparticle monolayer film in deionized water, and absorb the deionized water to obtain the PET-loaded nanoparticle monolayer film (DIW-Au@PS 12k -SH / PS 2K -C4 / PET)

[0117] Example 6

[0118] This example provides a nanoparticle monolayer film (DIW-Au@PCL 4k -SH / PCL 2K ) direct writing printing forming method, the specific steps are:

[0119] S1: Polycaprolactone (PCL 4k -SH) modified gold nanoparticles (Au NPs) by ligand exchange S , d = 15nm)), and then centrifugation and dichloromethane washing were repeated for 5 times, and then drying was performed to obtain thiol-terminated polycaprolactone grafted gold nanoparticles (Au@PCL 4k -SH);

[0120] S2: Au@PCL 4k -SH (60 mg / mL) and PCL 2k (6 mg / mL) was dispersed in dimethyl adipate to prepare nanoparticle colloid ink (Au@PCL 4k -SH / PCL 2k );

[0121] S3: Use a direct-write inkjet printer, set the printer nozzle outlet inner diameter to 50 μm, the printing line spacing to 150 μm, and the printing speed to 10,000 μm / s, and directly write on the cleaned silicon wafer surface. The contact angle between the nanoparticle colloidal ink and the silicon wafer surface is 22°, and a loaded nanoparticle monolayer film precursor is obtained;

[0122] S4: Place the nanoparticle-loaded monolayer film precursor in a vacuum drying oven and anneal the precursor in a toluene atmosphere at 80°C for 6 h to obtain a nanoparticle-loaded monolayer film (DIW-Au@PCL 4k -SH / PCL 2k / Si).

[0123] Example 7

[0124] This example provides a nanoparticle monolayer film (DIW-Au@PMMA 8k -SH / PMMA 3.2K ) direct writing printing forming method, the specific steps are:

[0125] S1: Polymethyl methacrylate (PMMA) 8k -SH) modified gold nanoparticles (Au NPs) by ligand exchange S , d = 15nm), and then centrifugation and dichloromethane washing were repeated for 5 times, and then drying was performed to obtain thiol-terminated polymethyl methacrylate grafted gold nanoparticles (Au@PMMA 8k -SH);

[0126] S2: Au@PMMA 8k -SH (50 mg / mL) and PMMA 3.2K (4 mg / mL) was dispersed in cyclooctanone to prepare nanoparticle colloid ink (Au@PMMA 8k -SH / PMMA 3.2K );

[0127] S3: Use a direct-write inkjet printer, set the printer nozzle outlet inner diameter to 50 μm, the printing line spacing to 150 μm, and the printing speed to 10,000 μm / s, and directly write on the cleaned silicon wafer surface. The contact angle between the nanoparticle colloidal ink and the silicon wafer surface is 22°, and a loaded nanoparticle monolayer film precursor is obtained;

[0128] S4: Place the nanoparticle-loaded monolayer film precursor in a vacuum drying oven and perform solvent annealing for 6 h at 80°C / toluene atmosphere to obtain a nanoparticle-loaded monolayer film (DIW-Au@PMMA 8k -SH / PMMA 3.2K / Si).

[0129] Example 8

[0130] This example provides a nanoparticle monolayer film (SC-Au@PS 5k -SH / PS 2K ) scraping printing forming method, the specific steps are:

[0131] S1: Preparation of nanoparticle colloidal ink (Au@PS 5k -SH / PS 2K , same as example 1);

[0132] S2: A fiber-guided liquid bridge printing device was used to print on the cleaned silicon wafer surface. The fiber length was 10 cm and the diameter was 80 μm. During the printing process, the substrate heating temperature was 50 °C, the fiber scraper was kept parallel to the substrate, and the height from the silicon wafer was 140 μm. The fiber moving speed was 1200 μm / s to obtain a nanoparticle-loaded monolayer film precursor (SC-Au@PS 5k -SH / PS 2K / Si);

[0133] S4: Place the nanoparticle-loaded monolayer film precursor in a vacuum drying oven and perform solvent annealing for 6 h at 80 °C / toluene atmosphere to obtain a nanoparticle-loaded monolayer film (SC-Au@PS 5k -SH / PS 2K / Si).

[0134] In order to illustrate the technical effect of the present application, this specification also provides comparative examples 1-3.

[0135] Comparative Example 1

[0136] The difference between this comparative example and Example 1 is that free polystyrene is omitted from the ink component, that is, the ink is specifically Au@PS 5k -SH (50 mg / mL) diphenyl ether solution, the other parameters and preparation steps are the same as in Example 1, and the obtained nanoparticle film is DIW-Au@PS 5k -SH / Si.

[0137] Comparative Example 2

[0138] The difference between this comparative example and Example 2 is that free polystyrene is omitted from the ink component, that is, the ink is specifically Au@PS 12k -SH (46 mg / mL) diphenyl ether solution, the other parameters and preparation steps are the same as Example 2, the obtained nanoparticle film is DIW-Au@PS 12k -SH / Si.

[0139] Comparative Examples 3-5

[0140] The difference between this comparative example and Example 1 is that the PS in the ink component 2k is replaced by a free homopolymer with different parameters, namely:

[0141] Comparative Example 3: The specific component is Au@PS 5k -SH / P4VP 2k , among which, P4VP 2k (Solubility parameter δ = 21.8–22.6 (J / cm 3 ) 1 / 2 , P4VP 2k With PS 5k -SH (solubility parameter δ = 18.6–19.0 ​​J / cm 3 ) 1 / 2 The solubility difference is greater than 2), and the prepared nanoparticle film is DIW-Au@PS 5k -SH / P4VP 2k / Si;

[0142] Comparative Example 4: The specific component is Au@PS 5k -SH / PCL 2k , where PCL 2k (Solubility parameter δ = 20.0–21.0 (J / cm 3 ) 1 / 2 , PCL 2k With PS 5k -SH (solubility parameter δ = 18.6–19.0 ​​J / cm 3 ) 1 / 2 The solubility difference is close to 2, and the prepared nanoparticle film is DIW-Au@PS 5k -SH / PCL 2k / Si;

[0143] Comparative Example 5: The specific component is Au@PS 5k -SH / PMMA 2k , among which PMMA 2k (Solubility parameter δ = 18.5–19.0 ​​(J / cm 3 ) 1 / 2 , PMMA 2k With PS 5k -SH (solubility parameter δ = 18.6–19.0 ​​J / cm 3 ) 1 / 2 The solubility difference is close to 1, and the prepared nanoparticle film is DIW-Au@PS 5k -SH / PMMA 2k / Si.

[0144] This paper also conducted morphology, structure and performance tests on the nanoparticle monolayer films prepared in the examples and comparative examples, as follows:

[0145] 1. Preparation of DIW-Au@PS 5k -SH / PS 2K / Si was used to characterize the macroscopic morphology, and the results were Figure 1 As shown. Among them, Figure 1 DIW-Au@PS 5k -SH / PS 2K Optical photograph of / Si.

[0146] according to Figure 1 It can be seen that Example 1 successfully prepared a nanoparticle film with a size of centimeters, specifically DIW-Au@PS 5k -SH / PS 2K / Si has an area of ​​1cm×1cm and no obvious impurities on the surface, indicating that the nanoparticle colloid ink provided in the present application can realize the direct writing printing of centimeter-level nanoparticle films.

[0147] 2. Preparation of DIW-Au@PS 5k -SH / PS 2K / Si was used to test the film thickness, and the results were Figure 2 As shown. Among them, Figure 2 DIW-Au@PS 5k -SH / PS 2K / Atomic force micrograph of Si.

[0148] according to Figure 2 It can be seen that the DIW-Au@PS prepared in Example 1 5k -SH / PS 2K / Si is a single-layer film, and the film thickness is 19.78nm, and the root mean square roughness is 0.92nm, which shows that the nanoparticle colloidal ink provided in the present application can realize the direct writing printing of nanoparticle single-layer film with a size of centimeter level.

[0149] 3. Preparation of DIW-Au@PS 5k -SH / PS 2K / Si was characterized by scanning electron microscopy, and the results were Figure 3 As shown. Among them, Figure 3 DIW-Au@PS 5k -SH / PS 2K / Si scanning electron microscope image.

[0150] according to Figure 3 It can be seen that the DIW-Au@PS prepared in Example 1 5k -SH / PS 2KThe interparticle distance of / Si is 9.42±0.78nm, and the nanoparticles are highly ordered.

[0151] 4. Storage performance test

[0152] In order to test the storage performance of the nanoparticle monolayer film prepared in this application for storage devices, the prepared DIW-Au@PS 5k -SH / PS 2K / Si is prepared into a memory device. The memory device is prepared as follows: -4 Under the pressure of Pa, The deposition rate was 40 nm for thermal evaporation of pentacene (P5) onto DIW-Au@PS 5k -SH / PS 2K After the evaporation of the semiconductor layer and the electrode, the memory device sample was obtained.

[0153] The test was conducted under ambient conditions, using a semiconductor parameter analyzer in a shielded box, with a wavelength of 410-800nm ​​and an intensity of 15mW·cm directly irradiated from the top of the device. -2 Commercial LEDs.

[0154] The specific testing process is:

[0155] When a negative voltage is applied to the gate, an electric field is generated from P5 to the gate. At this time, holes are induced in the P5 layer. After that, the holes enter the nanoparticles through direct tunneling from P5 and are captured and stored. Subsequently, voltage is applied to the source and drain electrodes, and the directional flow of electrons generates source-drain current, causing the transfer curve to shift negatively. This process is called negative writing. When illuminated, the large number of photogenerated carriers generated by P5 are divided into photogenerated electrons and photogenerated holes under the action of the built-in electric field. The former can tunnel into the nanoparticles and recombine with the previously stored holes, returning the transfer curve to its initial position. The positive writing and erasing of the device are exactly the opposite of the negative writing and erasing processes mentioned above. The test results are Figures 4 to 5 .in, Figure 4 a in the figure is different gate voltage (V GS ) under the source-drain current (I DS ) with source-drain voltage (V DS ) changes; Figure 4 b in the figure is different source-drain voltage (V DS ) under the source-drain current (I DS ) with gate voltage (V GS ) changes; Figure 4 c in the figure is the transfer curve of programming (Pro) / erasing (Era) threshold voltage; Figure 5 a in the figure is the read-write-erase-program cycle curve of the test memory device (repeating write-read-erase-read operations on the memory for many times); Figure 5 b in the figure is a retention time curve of the test memory device (under a fixed read voltage, the source-drain current variation with time in the write state and the erase state of the test memory).

[0156] according to Figure 4 From the ab in Example 1, it can be seen that the DIW-Au@PS 5k -SH / PS 2K / The memory device made of Si has good P-type field effect performance;

[0157] according to Figure 4 From the c in Example 1, it can be seen that the DIW-Au@PS 5k -SH / PS 2K The memory device made of / Si has a large bipolar storage window.

[0158] according to Figure 5 From the ab in Example 1, it can be seen that the DIW-Au@PS 5k -SH / PS 2K The memory devices made of / Si have good durability and strong stability.

[0159] 5. The nanoparticle monolayer films prepared in Examples 2-4 were tested by atomic force microscopy and scanning electron microscopy, and the test results were Figure 6 to Figure 7 As shown. Among them, Figure 6 Kelvin probe microscope surface potential image of the colloidal nanoparticle monolayer composite film prepared in Example 2-4; Figure 7 This is a scanning electron microscope image of the colloidal nanoparticle monolayer composite film prepared in Example 2-4.

[0160] according to Figure 6 It can be seen that the surface potential of the nanoparticle monolayer films prepared in Examples 2-4 shows a decreasing trend as the concentration of the free polymer increases, indicating that the addition of the free polymer can change the dielectric properties of the nanoparticle monolayer films.

[0161] according to Figure 7 It can be seen that as the concentration of free polymer increases, the spacing between the nanoparticles in the nanoparticle monolayer film prepared in Examples 2-4 tends to increase, indicating that the addition of free polymer can change the particle spacing of the nanoparticle monolayer film, and it is expected to prepare a patterned nanoparticle array by regulating the concentration of free polymer.

[0162] 6. Preparation of DIW-Au@PS 12k -SH / PS 2K-C1 / Si and DIW-Au@PS 12k -SH / Si was used for macroscopic morphology characterization, and the results were Figure 8 As shown. Among them, Figure 8 DIW-Au@PS 12k -SH / PS 2K -C1 / Si and DIW-Au@PS 12k -Optical photograph of SH / Si.

[0163] according to Figure 8 It can be seen that the nanoparticle monolayer film formed by direct writing printing with the nanoparticle colloid ink of the present application has a complete film morphology when desorbed on the water surface, while the nanoparticle monolayer film formed by direct writing printing with the nanoparticle colloid ink without adding free polymer in comparative example 2 is broken when desorbed on the water surface, indicating that the mechanical properties of the prepared nanoparticle monolayer film can be effectively improved by adding free polymer for compounding in the present application.

[0164] 7. Prepared DIW-Au@PS 12k -SH / PS 2K -C1 / PET was used to characterize the macroscopic and microscopic morphology. The results were Fig. 9 As shown. Among them, Fig. 9 a in the equation is DIW-Au@PS 12k -SH / PS 2K - Optical images of C1 / PET; Fig. 9 b in the figure is DIW-Au@PS 12k -SH / PS 2K -Scanning electron micrograph of C1 / PET.

[0165] according to Fig. 9 It can be seen that DIW-Au@PS 12k -SH / PS 2K -C1 / PET retains the original macroscopic and microscopic morphology.

[0166] 8. The nanoparticle monolayer films prepared in Examples 6 and 7 were characterized by scanning electron microscopy. Fig.10 As shown. Among them, Fig.10 a in the table is DIW-Au@PCL 4k -SH / PCL 2K / SEM image of Si; Fig.10 b in the figure is DIW-Au@PMMA 8K -SH / PMMA 2k / Si scanning electron microscope image.

[0167] according to Fig.10 It can be seen that the DIW-Au@PCL prepared in Example 6 4k-SH / PCL 2K / Si and DIW-Au@PMMA prepared in Example 7 8K -SH / PMMA 2k The surface of / Si is uniform and void-free, and the nanoparticles are arranged in an orderly hexagonal stack.

[0168] 9. SC-Au@PS formed by blade coating in Example 8 5k -SH / PS 2K / Si were characterized by optical photographs and scanning electron microscopy, and the results were Fig.11 As shown. Among them, Fig.11 a in the equation is SC-Au@PS 5k -SH / PS 2K Optical photograph of / Si; Fig.11 b in the figure is SC-Au@PS 5k -SH / PS 2K / Si scanning electron microscope image.

[0169] according to Fig.11 It can be seen that the SC-Au@PS formed by blade coating 5k -SH / PS 2K The / Si surface is also uniform without obvious impurities, and microscopically it is arranged in a long-range orderly hexagonal stacking pattern.

[0170] 10. Preparation of DIW-Au@PS 5k -SH / Si and DIW-Au@PS 12k -SH / Si was characterized by scanning electron microscopy, and the results were Fig.12 As shown. Among them, Fig.12 a in the equation is DIW-Au@PS 5k -SEM image of SH / Si, Fig.12 b in the figure is DIW-Au@PS 12k -Scanning electron microscope image of SH / Si.

[0171] according to Fig.12 It can be seen that the DIW-Au@PS formed by direct writing printing 12k -SH / Si and DIW-Au@PS 5k Obvious overlapping line traces can be observed on -SH / Si. The internal nanoparticles are unevenly distributed, with both unfilled areas and multi-layer stacked areas. The possible reasons for this phenomenon are: (1) the nanoparticle deposition speed is too fast, and the nanoparticles are deposited on the substrate before the two adjacent printing lines are completely fused together; (2) the influence of the coffee ring effect. When the solvent evaporates, the evaporation rate at the edge of the printing line is higher than that in the middle area, causing capillary flow from the middle to the edge, and ultimately causing the nanoparticles to be enriched at the edge of the printing line.

[0172] 11. Prepared DIW-Au@PS 5k -SH / P4VP 2k / Si、DIW-Au@PS 5k -SH / PCL 2k / Si and DIW-Au@PS 5k -SH / PMMA 2k / Si was characterized by scanning electron microscopy, and the results were Fig.13 As shown. Among them, Fig.13 DIW-Au@PS 5k -SH / P4VP 2k / Si、DIW-Au@PS 5k -SH / PCL 2k / Si and DIW-Au@PS 5k -SH / PMMA 2k / Si scanning electron microscope image.

[0173] according to Fig.13 It can be seen that in Comparative Example 3, the addition of the thiol-terminated polymer (PS 5k When the solubility parameter difference between the free polymer (P4VP) and Au@PS-SH) is greater than 2, the compatibility between the free polymer and Au@PS-SH NPs is poor, the film morphology is severely phase-separated, and the nanoparticles are disorderly arranged on the substrate ( Fig.13 a); and in Comparative Example 4, a thiol-terminated polymer (PS 5k -SH) with a solubility parameter difference of less than 2 for free polymers (PCL 2k ), the compatibility of the free polymer and Au@PS-SH NPs is within the critical value, the film morphology has weak phase separation, and the nanoparticles are orderly arranged on the substrate ( Fig.13 b); while in Comparative Example 5, a thiol-terminated polymer (PS 5k -SH) with a solubility parameter difference of less than 1 for free polymer (PMMA 2k ), the free polymer has good compatibility and the nanoparticles are highly ordered on the substrate ( Fig.13 c). Therefore, the present application preferably adds a free polymer having a solubility parameter difference of less than 2 with the thiol-terminated polymer, and more preferably adds a free polymer having a solubility parameter difference of less than 1 with the thiol-terminated polymer.

[0174] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0175] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A nanoparticle colloid ink, characterized in that: The composition comprises the following solute components and an ink solvent having a boiling point higher than 150°C: (a) Thiol-terminated polymer-grafted core-shell nanoparticles; (b) a free polymer having a solubility parameter that differs from that of the thiol-terminated polymer by less than 2.

2. The nanoparticle colloid ink according to claim 1, characterized in that: The thiol-terminated polymer is one of a thiol-terminated polystyrene homopolymer, a thiol-terminated polyepoxy homopolymer, and a thiol-terminated polyacrylate homopolymer; and, The free polymer is one of polystyrene homopolymer, polyepoxy homopolymer and polyacrylate homopolymer.

3. The nanoparticle colloid ink according to claim 1, characterized in that: The nanoparticle core constituting the thiol-terminated polymer-grafted core-shell nanoparticles is one of metal nanoparticles, metal oxide nanoparticles, and SiO2 nanoparticles; And / or, the metal nanoparticles are gold nanoparticles, silver nanoparticles and combinations thereof; And / or, the metal oxide nanoparticles are ZnO2 nanoparticles, Fe3O4 nanoparticles and combinations thereof.

4. The nanoparticle colloid ink according to claim 3, characterized in that: The shape of the nanoparticle core is one of a sphere, a cube and a polyhedron; Wherein, the diameter of the spherical nanoparticle core is 5-50nm.

5. The nanoparticle colloid ink according to claim 1, characterized in that: The dispersed concentration of the solute component is: (a) Thiol-terminated polymer-grafted core-shell nanoparticles 20-80 mg / mL; (b) Free polymer 1-10 mg / mL.

6. The nanoparticle colloid ink according to claim 1, characterized in that: The ink solvent is one of butylbenzene, dimethyl adipate, diphenyl ether and cyclooctanone.

7. The nanoparticle colloid ink according to claim 1, characterized in that: The molecular weight of the free polymer is 2000-5000 g / mol; The molecular weight of the thiol-terminated polymer is 2000-50000 g / mol.

8. A nanoparticle monolayer film, characterized in that: The invention comprises a nanoparticle array formed by printing using the nanoparticle colloid ink described in any one of claims 1 to 6.

9. A method for preparing the nanoparticle monolayer film according to claim 8, characterized in that: Include: Setting the nanoparticle array; The nanoparticle colloid ink is used to print and construct the nanoparticle array on the surface of a substrate, and then solvent annealing and water immersion desorption are performed in sequence.

10. Use of the nanoparticle monolayer film according to claim 8 in preparing nano floating gate memory, surface Raman enhancement substrate, and solar cell.

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