A method for regulating micro-nano patterns of crystalline block copolymers

Abstract

The application discloses a method for regulating and controlling micro-nano patterns of crystalline block copolymer, which comprises the following steps: a solution of polyethylene oxide-poly(2-vinylpyridine) (PEO-P2VP) block copolymer is spin-coated on a silicon wafer to obtain a PEO-P2VP film; the spin-coated film is annealed at different temperatures, and then is placed into a Linkam hot stage to perform melt isothermal crystallization; by changing the annealing temperature, the melt temperature of melt heat treatment and the melt time, the lamellar patterns in the PEO-P2VP film can be regulated and controlled. b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). The method has the advantages of simple operation, low equipment requirement, and the ability to form nano-pattern arrays with controllable density, size and morphology on a large area, which opens up new possibilities for the application of multifunctional nano materials, and has extremely important significance for the future development of block copolymer materials.

Description

Technical Field

[0001] This invention belongs to the field of polymer micro and nanomaterial processing technology, specifically relating to a method for controlling the micro and nano patterns of crystalline block copolymers. Background Technology

[0002] PEO is chemically inert and non-toxic, exhibiting good solubility in common organic solvents and water. Its excellent physicochemical properties have led to increasing interest in PEO-related materials. Among them, PEO-containing block copolymers show great potential in materials science, nanotechnology, and life sciences. They have been used to manufacture surface coatings, utilizing their antifouling properties to prevent the adsorption of proteins, cells, bacteria, and other microorganisms.

[0003] Polymer ultrathin films have attracted widespread attention due to their importance in scientific and industrial applications, and are commonly used in the design and fabrication of nanomaterials (ultrathin polymer layers) and nanodevices (optoelectronic devices, semiconductor devices, magnetic dielectric storage devices). The mechanical properties of polymer ultrathin films are highly dependent on their micro / nano patterning, thus crystalline polymers play a crucial role in related fields. Researchers have consistently strived to develop new and simple strategies for precisely controlling the micro / nano patterns within thin films. Simultaneously, the high controllability of nanopatterns offers limitless possibilities for developing multifunctional nanostructures. Summary of the Invention

[0004] This invention provides a method for controlling the micro / nano patterning of crystalline block copolymers, by changing PEO- b - The annealing temperature of the P2VP film, the melting temperature and melting time for melt heat treatment, and the control of PEO- b -P2VP thin film lamellar pattern.

[0005] This invention is achieved through the following technical solution: a method for controlling the micro / nano patterning of crystalline block copolymers, characterized in that the method includes the following steps:

[0006] (1) PEO- b -P2VP raw material is completely dissolved in toluene solvent to obtain PEO- b -P2VP solution;

[0007] (2) Using a silicon wafer treated with ultraviolet light oxidation as a substrate, a solution was spin-coated onto the substrate using a spin coater to prepare PEO- b -P2VP thin film;

[0008] (3) Annealing the film in hot stands at different temperatures to obtain PEO- in different morphologies. b -P2VP initial crystal, then quickly remove the thin film sample from the hot stage and quench it to room temperature;

[0009] (4) Thin film melting isothermal crystallization was carried out under a nitrogen protective atmosphere, and the melting temperature and melting time of the melt heat treatment were changed to achieve the desired crystallization in PEO- b Different micro / nano structure patterns were prepared in the P2VP thin film. The heat treatment temperature program was as follows: the temperature was increased from room temperature to the melting temperature at a heating rate of 80 °C / min and held at that temperature for a period of time. Then the temperature was decreased to 50 °C at a cooling rate of 30 °C / min and isothermally crystallized at that temperature.

[0010] Furthermore, in step (1), PEO- b -P2VP has a number-average molecular weight of 42000-27000 g / mol, and the PEO- in the prepared solution b The mass fraction of -P2VP is 1.1 wt%.

[0011] Furthermore, in step (1), during the preparation of the solution, after the raw materials are mixed with toluene solvent, the solution is heated on a hot plate at 75 °C for 60 min, and stirred continuously to ensure that the raw materials are fully dissolved.

[0012] Furthermore, in step (2), the silicon wafer is subjected to ultraviolet light oxidation treatment for 45 min to improve the hydrophilicity of the silicon wafer.

[0013] Furthermore, in step (2), PEO is... -b- The P2VP solution was uniformly dropped onto the silicon wafer, and the spin coating operation was specifically performed by spin coating at a speed of 4000 rpm for 30 s.

[0014] Furthermore, in step (3), the annealing process is carried out at a temperature of 25 °C ~ 35 °C and an annealing time of 40 min.

[0015] Furthermore, in step (4), during the melting heat treatment process, the melting temperature is 59.5 °C ~ 60.7 °C and the melting time is 1 s ~ 180 min.

[0016] Furthermore, in step (4), during the isothermal crystallization process, the crystallization temperature is 50 °C and the crystallization time is 10 min ~ 90 min.

[0017] Compared with the prior art, the present invention has the following positive and beneficial effects:

[0018] Due to thermodynamic instability and kinetic hindrance, large-scale control of the ordering of nanopatterns has always been a challenge. The method described in this invention can form a nanopattern array with controllable density, size, and morphology over a large area through simple heat treatment, thereby achieving the regulation of lamellar patterns in polymer films at the micro- and nanoscale. This is of great significance for obtaining micro- and nanopatterns with predetermined properties.

[0019] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only four of the drawings in this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 The PEO- after annealing at 25 °C as described in Example 1 b -Atomic force microscopy characterization results of P2VP thin film samples after being treated at different melting temperatures and then isothermally crystallized at 50 °C for 10 min;

[0022] Figure 2 The PEO- after annealing at 30 °C as described in Example 1 b -Atomic force microscopy characterization results of P2VP thin film samples after being treated at different melting temperatures and then isothermally crystallized at 50 °C for 10 min;

[0023] Figure 3 The PEO- after annealing at 35 °C as described in Example 1 b -Atomic force microscopy characterization results of P2VP thin film samples after being treated at different melting temperatures and then isothermally crystallized at 50 °C for 10 min;

[0024] Figure 4 The PEO- after annealing at 25 °C as described in Example 2 b -Atomic force microscopy characterization results of P2VP thin film samples after different melting times and isothermal crystallization at 50 °C for 90 min. Detailed Implementation

[0025] The present invention will now be described in more detail through specific embodiments to facilitate understanding of the technical solution of the present invention. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders. In addition, the method embodiments may include additional steps or omit the steps shown. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0026] The PEO- used in the following examples b -P2VP (polyoxyethylene- b The poly(2-vinylpyridine) was purchased from Polymer Source, Canada, with molecular weights ranging from 42,000 to 27,000 g / mol. The PEO block has a main chain structure of -CH2-CH2-O-, exhibiting good flexibility and ease of crystallization, with a number-average molecular weight of 42,000 g / mol and a glass transition temperature of approximately –67°C. The P2VP amorphous block has a number-average molecular weight of 27,000 g / mol. T g The temperature was approximately 87 °C. The silicon wafers used were P100 wafers manufactured by Zhejiang Lijing Optoelectronics Technology Co., Ltd. The hot stage was a Linkam hot and cold stage, and the spin microscope was a KW-4A model manufactured by the Institute of Microelectronics, Chinese Academy of Sciences. The atomic force microscope (AFM) used was purchased from Bruker Corporation, USA (model: Icon), and the ellipsometer used was an alpha-SE from JA Woollam Co., USA.

[0027] Example 1

[0028] This example is used to verify the effects of annealing temperature and melting temperature on PEO. -b- The effects of P2VP crystallization patterns include the following steps:

[0029] (1) Preparation of PEO -b- P2VP solution:

[0030] Using toluene as solvent, and PEO with a number average molecular weight of 42000-27000 g / mol -b- P2VP was used as the solute, and a solution with a concentration of 1.1 wt% was prepared. The solution was then placed on a hot plate at 75 °C and heated for 60 min, with constant stirring to ensure that the solute was fully dissolved.

[0031] (2) Preparation of PEO -b- P2VP film:

[0032] Take a P100 type silicon wafer and place it under a UV lamp for 45 min to oxidize it to improve its hydrophilicity. After the treatment, place the silicon wafer on a spin coater and apply the PEO prepared in step (1). -b- A P2VP solution (0.01 ~ 0.04 g) was uniformly dropped onto a silicon wafer, and then spin-coated at 4000 rpm for 30 s to obtain a PEO film with a thickness of 36 nm. -b- P2VP film;

[0033] (3) PEO -b- P2VP thin film annealing to prepare initial crystals:

[0034] Three groups of PEO -b- P2VP spin-coated thin film samples were placed in Linkam hot stages at different temperatures (25 °C, 30 °C, 35 °C) for 40 min to obtain initial crystals with different morphologies. The thin film samples were then quickly removed from the hot stage and quenched to room temperature.

[0035] (4) PEO -b- Melt isothermal crystallization of P2VP thin film:

[0036] The film was placed in a Linkam hot stage and melted isothermally crystallized under a nitrogen protective atmosphere. The heat treatment temperature program was as follows: the temperature was increased from room temperature to the melting temperature (59.5 °C, 59.7 °C, 60.0 °C, 60.2 °C, 60.5 °C, 60.7 °C) at a heating rate of 80 °C / min and held at that temperature for 3 min, then cooled to 50 °C at a cooling rate of 30 °C / min and isothermally crystallized at that temperature for 10 min.

[0037] The crystal obtained by isothermal crystallization of the thin film was characterized using atomic force microscopy. The characterization results are as follows: Figure 1-3 As shown;

[0038] like Figure 1 The image shows six groups of PEO- annealed at 25 °C for 40 min. b Atomic force microscopy (AFM) characterization results of P2VP thin film samples after being treated at different melting temperatures and then isothermally crystallized at 50 °C for 10 min. Figure 1 The results show that PEO- can be tuned at the micro-nano scale by changing the melting temperature. b -Density of small crystals within the P2VP crystal pattern.

[0039] like Figure 2 The image shows six groups of PEO- annealed at 30 °C for 40 min. b- Atomic force microscopy characterization results of P2VP thin film samples after being treated at different melting temperatures and then isothermally crystallized at 50 °C for 10 min.

[0040] like Figure 3 The image shows six groups of PEO- annealed at 35 °C for 40 min. b - Atomic force microscopy characterization results of P2VP thin film samples after being treated at different melting temperatures and then isothermally crystallized at 50 °C for 10 min.

[0041] Depend on Figure 1-3 The results show that PEO- can be tuned at the micro-nano scale by changing the annealing temperature. b -Density of small crystals within the P2VP crystal pattern.

[0042] Example 2

[0043] This example is used to verify the effect of melting time on PEO. -b- The effects of P2VP crystallization patterns include the following steps:

[0044] (1) Preparation of PEO -b- P2VP solution:

[0045] Using toluene as solvent, and PEO with a number average molecular weight of 42000-27000 g / mol -b- P2VP was used as the solute, and a solution with a concentration of 1.1 wt% was prepared. The solution was then placed on a hot plate at 75 °C and heated for 60 min, with constant stirring to ensure that the solute was fully dissolved.

[0046] (2) Preparation of PEO -b- P2VP film:

[0047] Take a P100 type silicon wafer and place it under a UV lamp for 45 min to oxidize it to improve its hydrophilicity. After the treatment, place the silicon wafer on a spin coater and apply the PEO prepared in step (1). -b- A P2VP solution (0.01 ~ 0.04 g) was uniformly dropped onto a silicon wafer, and then spin-coated at 4000 rpm for 30 s to obtain a PEO film with a thickness of 36 nm. -b- P2VP film;

[0048] (3) PEO -b- P2VP thin film annealing to prepare initial crystals:

[0049] PEO -b- The P2VP spin-coated thin film sample was placed in a Linkam hot stage at 25 °C for annealing to obtain initial crystals. The thin film sample was then quickly removed from the hot stage and quenched to room temperature.

[0050] (4) PEO -b- Melt isothermal crystallization of P2VP thin film:

[0051] The film was placed in a Linkam hot stage and melted isothermally crystallized under a nitrogen protective atmosphere. The heat treatment temperature program was as follows: the temperature was increased from room temperature to 60.7 °C at a heating rate of 80 °C / min and held at this temperature for different melting times (1 s, 1 min, 30 min, 60 min, 180 min), then cooled to 50 °C at a cooling rate of 30 °C / min and isothermally crystallized at this temperature for 90 min.

[0052] The crystal obtained by isothermal crystallization of the thin film was characterized using atomic force microscopy. The characterization results are as follows: Figure 4 As shown;

[0053] like Figure 4 The image shows five groups of PEO- after annealing at 25 °C. b Atomic force microscopy (AFM) characterization results of P2VP thin film samples after different melting times followed by isothermal crystallization at 50 °C for 90 min. Figure 4 The results show that PEO- can be tuned at a smaller scale (individual small crystals within the array pattern) by changing the melting time. b - The morphology of the P2VP crystal pattern.

[0054] The results of Examples 1 and 2 show that by changing PEO- b The annealing temperature and melting temperature for heat treatment of P2VP films can be controlled at the micro-nano scale. b - The density of small crystals inside the lamellar pattern obtained by P2VP isothermal crystallization; furthermore, by changing the melting time of the molten heat treatment, the morphology of the lamellar pattern can be controlled at a smaller scale (individual small crystals inside the array pattern), thereby significantly affecting the overall micro-nano pattern.

[0055] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. Therefore, all equivalent changes or modifications made to the structure, features, and principles described in the claims of this invention should be included within the scope of the patent application. Thus, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. More other equivalent embodiments may be included without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for controlling the micro / nano patterning of crystalline block copolymers, characterized in that, The method includes the following steps: (1) PEO- b -P2VP raw material is completely dissolved in toluene solvent to obtain PEO- b -P2VP solution; (2) Using a silicon wafer treated with ultraviolet light oxidation as a substrate, a solution was spin-coated onto the substrate using a spin coater to prepare PEO- b -P2VP thin film; (3) Annealing the film in hot stands at different temperatures to obtain PEO- in different morphologies. b -P2VP initial crystal, then quickly remove the thin film sample from the hot stage and quench it to room temperature; (4) Thin film melting isothermal crystallization was carried out under a nitrogen protective atmosphere, and the melting temperature and melting time of the melt heat treatment were changed to achieve the desired crystallization in PEO- b Different micro / nano structure patterns were prepared in the P2VP thin film. The heat treatment temperature program was as follows: the temperature was increased from room temperature to the melting temperature at a heating rate of 80 °C / min and held at the temperature for a period of time, and then the temperature was decreased to 50 °C at a cooling rate of 30 °C / min and isothermally crystallized at the temperature. In step (3), during the annealing process, the annealing temperature is 25 °C ~ 35 °C and the annealing time is 40 min; In step (4), during the melting heat treatment process, the melting temperature is 59.5 °C ~ 60.7 °C and the melting time is 1s ~ 180 min; In step (4), during the isothermal crystallization process, the crystallization temperature is 50 °C and the crystallization time is 10 min ~ 90 min.

2. The method for controlling the micro / nano patterning of crystalline block copolymers according to claim 1, characterized in that, In step (1), the number-average molecular weight of the PEO block is 42000 g / mol, and the number-average molecular weight of the P2VP amorphous block is 27000 g / mol. The prepared solution contains PEO- b The mass fraction of -P2VP is 1.1 wt%.

3. The method for controlling the micro / nano patterning of crystalline block copolymers according to claim 1, characterized in that, In step (1), during the preparation of the solution, after the raw materials are mixed with toluene solvent, the solution is heated on a hot plate at 75 °C for 60 min, and stirred continuously to ensure that the raw materials are fully dissolved.

4. The method for controlling the micro / nano patterning of crystalline block copolymers according to claim 1, characterized in that, In step (2), the silicon wafer is subjected to ultraviolet light oxidation treatment for 45 min to improve the hydrophilicity of the silicon wafer.

5. The method for controlling the micro / nano patterning of crystalline block copolymers according to claim 1, characterized in that, In step (2), PEO -b- The P2VP solution was uniformly dropped onto the silicon wafer, and the spin coating operation was specifically performed by spin coating at a speed of 4000 rpm for 30 s.

Images