A method for measuring the interface microstructure information of polymer-based nanometallic composite material

Abstract

This invention belongs to the field of interface performance measurement technology for nanocomposite materials, and provides a method for measuring the microscopic information of the interface of polymer-based nanocomposite materials. The method includes the following steps: S1: A dual-beam Raman system collects the interface Raman signal generated by plasmon resonance in the polymer-based nanocomposite material; S2: A dual-beam Raman system collects the intrinsic Raman signal of the polymer matrix; S3: A dual-beam Raman system collects the pure polymer Raman signal of the same polymer material without nanocomposite materials; S4: The interface Raman signal, intrinsic Raman signal, and pure polymer Raman signal are compared and analyzed to obtain the interface microscopic information. Using the method provided by this invention, the interface information of the polymer / nanocomposite material can be accurately and non-destructively obtained by combining the acquired interface Raman signal and intrinsic Raman signal.

Description

Technical Field

[0001] This invention belongs to the field of nanocomposite material interface performance measurement technology, specifically relating to a method for measuring the microscopic information of the interface of polymer-based nanocomposite noble metal composite materials. Background Technology

[0002] Polymer / nano-noble metal composites, consisting of a polymer matrix and nanofillers, are a class of advanced packaging materials that play a crucial role in the integrated circuit industry. They can be used as wafer-level epoxy molding compounds, chip-level substrate fillers, and thermal interface materials required for electronic packaging. [1] However, the high-temperature environment generated during the operation of electronic devices can accelerate the aging of polymer / nano-noble metal composite materials, leading to a decline in the performance and a shortened lifespan of the electronic devices. [2] Research on the aging mechanism of polymer / nano-precious metal composites is of great significance: by monitoring the aging process and remaining service life of polymer / nano-precious metal composites in real time, materials that no longer meet performance standards can be replaced in a timely manner, ensuring the efficient and safe operation of electronic devices; on the other hand, it can provide theoretical guidance for the development of polymer / nano-precious metal composites with better performance.

[0003] Current research on the aging mechanisms of polymer / nano-noble metal composites typically employs polymer characterization methods directly, often neglecting the crucial role of the interface between the nanofiller and the polymer in the composite material. The microstructure of the interface is influenced not only by factors such as the surface chemical modification of the nanofiller but also by the polymer type and microphase morphology. [3,4] These influencing factors can cause the microscopic properties of the molecular chains at the interface to differ significantly from those of the polymer matrix. [5,6] More importantly, the microscopic state of molecules at the interface, through the large specific surface area and high surface activity of the nanofiller, greatly influences the properties of the polymer / nano-noble metal composite material. [7] Therefore, studying the aging mechanism of the interface in polymer / nano-noble metal composites is crucial for understanding these composites and regulating their properties.

[0004] However, traditional characterization methods, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), or X-ray diffraction (XRD), are not accurate in obtaining information about the interface microstructure of polymer nanocomposites. These methods require disrupting the polymer nanocomposites to expose the interface for study, which destroys the original structure and results in information loss.

[0005] The biggest drawback of current technology is the inability to obtain accurate microscopic information about the interface of polymer / nano-precious metal composite materials.

[0006] References:

[0007] [1] Liu Peidong, Hu Xiaodan, Song Shihui, et al. Research progress on polymer-based electronic packaging materials [J]. Engineering Plastics Application, 2022, 50(07):160-167.

[0008] [2]Low, ZX, Budd PM, Mckeown NB, et al. Gas permeation properties, physical aging, and its mitigation in high free volume glassy polymers[J]. Chem. Rev., 2018, 118(12): 5871-5911.

[0009] [3]Gao,K.,Wan HX,Tsen EJL,et al.Unveiling the mechanism of thelocation of the grafted nanoparticles in a lamellar-forming block copolymer[J].Langmuir,2020,36(1):194-203.

[0010] [4]Gao, K., Zhao HH, Wang YC, et al. Heterogeneous dynamics of polymermelts exerted by chain loops anchored on the substrate: Insights from molecular dynamics simulation [J]. Langmuir, 2021, 37(42): 12290-12303.

[0011] [5] Zhao, HH, Wei XF, Fang Y., et al. Molecular dynamics simulation of the structural, mechanical, and reprocessing properties of vitrimers based on adynamic covalent polymer network [J]. Macromolecules, 2022, 55(4): 1091-1103.

[0012] [6] Chang, ZC, Wang YF, Zhang ZY, et al. Creep behavior of polymernanocomposites: Insights from molecular dynamics simulation[J]. Polymer, 2021, 228.

[0013] [7]Idumah,CI,Obele CMUnderstanding interfacial influence onproperties of polymer nanocomposites[J].Surf.Interfaces,2021,22. Summary of the Invention

[0014] To address the problem of obtaining accurate microscopic information about the interface of polymer / nano-noble metal composite materials, this invention provides a method for measuring the microscopic information of the interface of polymer-based nano-noble metal composite materials, wherein the polymer-based nano-noble metal composite material includes a polymer substrate and nano-noble metal fillers.

[0015] The method for measuring the interfacial microstructure of polymer-based nanocomposite noble metals includes the following steps:

[0016] S1: The dual-beam Raman system uses a first-wavelength laser to excite the plasmonic resonance of the polymer-based nano-noble metal composite material to obtain the interface Raman signal;

[0017] S2: The dual-beam Raman system uses a second-wavelength laser to collect the intrinsic Raman signal of the polymer matrix;

[0018] S3: The dual-beam Raman system uses the first wavelength and the second wavelength laser to collect pure polymer Raman signals of the same polymer material that does not contain nano-precious metals;

[0019] S4: Compare and analyze the interface Raman signal obtained in S1, the intrinsic Raman signal obtained in S2, and the Raman signal obtained in S3 to obtain the interface microscopic information.

[0020] Furthermore, the interface microscopic information includes vibrational information of molecular groups, micro-region stress information, molecular configuration and conformation information, and molecular aggregation state information.

[0021] Furthermore, the interface Raman signal in S1 includes first Raman characteristic peak information and first fluorescence background information. The first Raman characteristic peak information includes the number, position, width, intensity, area, and relative intensity of the first Raman characteristic peak.

[0022] Furthermore, the intrinsic Raman signal mentioned in S2 includes second Raman characteristic peak information and second fluorescence background information. The second Raman characteristic peak information includes the number, position, width, intensity, area, and relative intensity of the second Raman characteristic peak.

[0023] Furthermore, the multi-dimensional comprehensive analysis described in S3 includes a comparative analysis of the first Raman characteristic peak information, the second Raman characteristic peak information, the first fluorescence background information, and the second fluorescence background information.

[0024] Furthermore, the power of the first wavelength laser and the second wavelength laser is between 1mW and 100mW.

[0025] Furthermore, the integration time of the dual-beam Raman system is between 1s and 1000s.

[0026] Furthermore, the wavelengths of the first wavelength laser and the second wavelength laser are selected from any two of 266nm, 325nm, 514nm, 532nm, 633nm, 785nm, 830nm and 1064nm.

[0027] Furthermore, the polymer substrate is selected from one or more of epoxy resin, polyimide, and silicone.

[0028] Furthermore, the nano-precious metal filler is selected from one or more of gold, silver, and copper.

[0029] The method for detecting interface information of polymer / nano-noble metal composite materials using a dual-beam Raman system provided by this invention accurately and non-destructively obtains interface information of polymer / nano-noble metal composite materials by combining the acquired interface Raman signal and intrinsic Raman signal. Attached Figure Description

[0030] Figure 1 A flowchart of the method for measuring the interface microstructure of polymer-based nano-noble metal composite materials provided by the present invention;

[0031] Figure 2 A schematic diagram of the method for measuring the interface microstructure of polymer-based nano-noble metal composite materials provided by the present invention;

[0032] Figure 3 Microscopic images of simple polymers and polymer-based nano-noble metal composites are provided for this invention;

[0033] Figure 4 The interface Raman spectrum and intrinsic Raman spectrum provided in Embodiment 1 of the present invention. Detailed Implementation

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but this should not be construed as limiting the scope of the present invention.

[0035] To accurately and non-destructively obtain the interfacial microscopic information of polymer / nano-noble metal composite materials, this invention proposes a method for probing the interfacial information of polymer / nano-noble metal composite materials using a dual-beam Raman system. By endowing the composite material with enhanced Raman properties, and combining the dual-beam Raman system to obtain the surface-enhanced Raman signal at the interface, the polymer matrix signal outside the interface, and the pure polymer Raman signal of the same polymer material without nano-noble metal fillers, the molecular information at the interface can be accurately located.

[0036] This invention provides a method for measuring the interfacial microstructure of polymer-based nano-noble metal composite materials, wherein the polymer-based nano-noble metal composite material comprises a polymer substrate and nano-noble metal fillers.

[0037] The method for measuring the interfacial microstructure of polymer-based nanocomposite noble metals includes the following steps:

[0038] S1: The dual-beam Raman system uses a first-wavelength laser to excite the plasmonic resonance of the polymer-based nano-noble metal composite material to obtain the interface Raman signal;

[0039] S2: The dual-beam Raman system uses a second-wavelength laser to collect the intrinsic Raman signal of the polymer matrix;

[0040] S3: The dual-beam Raman system uses the first wavelength and the second wavelength laser to collect pure polymer Raman signals of the same polymer material that does not contain nano-precious metals;

[0041] S4: Compare and analyze the interface Raman signal obtained in S1, the intrinsic Raman signal obtained in S2, and the pure polymer Raman signal obtained in S3 to obtain the interface microstructure information.

[0042] When light waves (electromagnetic waves) are incident on the interface between a metal and a dielectric, the free electrons on the metal surface undergo collective oscillation. The electromagnetic wave couples with the free electrons on the metal surface to form a near-field electromagnetic wave that propagates along the metal surface. If the oscillation frequency of the electrons matches the frequency of the incident light wave, plasmon resonance occurs. In the plasmon resonance state, the energy of the electromagnetic field is effectively converted into the collective vibrational energy of the free electrons on the metal surface. This forms a special electromagnetic mode where the electromagnetic field is confined to a very small area on the metal surface and is amplified. This phenomenon is called surface plasmon resonance. Plasmon resonance amplifies the Raman scattering signal at the composite material interface, making it easier to capture the interface Raman signal.

[0043] By comparing the interface Raman signal, the intrinsic Raman signal, and the pure polymer Raman signal, the microscopic information of the interface of polymer-based nano-noble metal composite materials can be obtained accurately and non-destructively, and then the interface properties can be determined through the interface microscopic information.

[0044] Specifically, the interface microscopic information includes vibrational information of molecular groups, micro-region stress information, molecular configuration and conformation information, and molecular aggregation state information.

[0045] Specifically, the interface Raman signal in S1 includes first Raman characteristic peak information and first fluorescence background information. The first Raman characteristic peak information includes the number, position, width, intensity, area, and relative intensity of the first Raman characteristic peak.

[0046] The intrinsic Raman signal described in S2 includes second Raman characteristic peak information and second fluorescence background information. The second Raman characteristic peak information includes the number, position, width, intensity, area, and relative intensity of the second Raman characteristic peak.

[0047] The multi-dimensional comprehensive analysis described in S3 includes a comparative analysis of the first Raman characteristic peak information, the second Raman characteristic peak information, the first fluorescence background information, and the second fluorescence background information.

[0048] Preferably, the power of the first wavelength laser and the second wavelength laser is between 1mW and 100mW. Too low a power will result in no noticeable signal, while too high a power may damage the sample.

[0049] Preferably, the integration time of the dual-beam Raman system is between 1s and 1000s. Too short a time results in no noticeable signal, while too long a time can lead to signal overflow. The integration time needs to be set according to the power; generally, the higher the power, the shorter the integration time.

[0050] Preferably, the wavelengths of the first and second wavelength lasers are selected from any two of 266nm, 325nm, 514nm, 532nm, 633nm, 785nm, 830nm, and 1064nm. Generally, different noble metal nanofillers require different laser wavelengths to generate resonance, and different laser wavelengths are required to collect information from different polymer matrices. Therefore, it is necessary to select two suitable wavelengths to build a dual-beam Raman system based on different types of noble metal fillers and polymer matrices.

[0051] Preferably, the polymer substrate is selected from one or more of epoxy resin, polyimide, and silicone.

[0052] Preferably, the nano-precious metal filler is selected from one or more of gold, silver and copper.

[0053] Example 1: Dual-beam Raman detection of polydimethylsiloxane / silver nanowires

[0054] S1: The polydimethylsiloxane / silver nanowire material to be tested is observed under a 3D ultra-depth microscope, and the silver nanowires mixed into the matrix can be seen.

[0055] The purpose of this step is to observe whether the silver wires are uniformly distributed in polydimethylsiloxane. Under the premise of uniform distribution, the interface micro information obtained by the method for measuring the interface micro information of polymer-based nano-noble metal composite materials provided by this invention is more accurate and can truly reflect the microstructure of the interface.

[0056] S2: Cut the polydimethylsiloxane / silver nanowire material into a small square of 1 cm * 1 cm * 0.2 cm, place its lower surface on aluminum foil and place it together on the sample stage of the Raman detection platform, keeping its upper surface flat.

[0057] S3: First, a dual-beam Raman system with a wavelength of 532nm, a laser power of 0.37W, and an integration time of 20s was used to perform Raman detection on the surface of each sample to obtain the interface Raman signal.

[0058] S4: Then, use a dual-beam Raman system to excite at a wavelength of 785nm, a laser power of 0.37W, and an integration time of 30s to perform Raman detection at the same point to obtain the intrinsic Raman signal.

[0059] S5: Analyze the differences between the interface Raman spectrum and the intrinsic Raman spectrum under different light beams (number of characteristic peaks, shift, relative intensity, fluorescence background signal, etc.). Observe the characteristic peaks of the two spectra. If a characteristic peak that is not present in the 785nm spectrum appears in the Raman spectrum of the 532nm laser, then the information of this characteristic peak represents the interface Raman signal at the interface of the composite material.

[0060] S6: Using this dual-beam Raman system to detect pure polydimethylsiloxane material, a pure polymer Raman signal is obtained. If no difference in the spectrum as in step S5 is produced, it can be further proved that the characteristic peak information obtained in step S5 is the interface micro information at the interface of the composite material.

[0061] In Example 1, the pure polymer Raman signal obtained in S6 was: Figure 4 In Figure a, the interface Raman signal obtained in S3 is Figure 4 The upper curve in figure b, the intrinsic Raman signal obtained in S4 is Figure 4The lower curve in Figure b is shown in Figure a. In Figure a, the Raman signals of the pure polymer at different laser wavelengths show little difference. However, in Figure b, after adding silver lines, the Raman signal at 532 nm is significantly stronger than that at 785 nm, proving that the silver lines enhance the 532 nm wavelength laser. This indicates that the Raman signal at 532 nm after adding silver lines is the interface signal between the silver lines and the polymer. Furthermore, compared to the 532 nm Raman spectrum of the pure polymer, the interface signal has two additional characteristic peaks at 1597 and 2501, indicating that the molecular microstate of the polymer at the interface differs from that in the bulk.

Claims

1. A method for measuring the interfacial microstructure of a polymer-based nanocomposite material, wherein the polymer-based nanocomposite material comprises a polymer substrate and nanocomposite material fillers, characterized in that, Includes the following steps: S1: The dual-beam Raman system uses a first-wavelength laser to excite plasmonic resonance in the polymer-based nano-noble metal composite material to obtain Raman signals from the interface and the polymer bulk. S2: The dual-beam Raman system uses a second-wavelength laser to collect the intrinsic Raman signal of the polymer matrix; S3: The dual-beam Raman system uses the first wavelength and the second wavelength laser to collect pure polymer Raman signals of the same polymer material that does not contain nano-precious metals; S4: Compare and analyze the interface Raman signal obtained in S1, the intrinsic Raman signal obtained in S2, and the pure polymer Raman signal obtained in S3 to obtain the interface microstructure information.

2. The method for measuring the interfacial microstructure of polymer-based nano-noble metal composite materials as described in claim 1, characterized in that, The interface microscopic information includes vibrational information of molecular groups, micro-region stress information, molecular configuration and conformation information, and molecular aggregation state information.

3. The method for measuring the interfacial microstructure of polymer-based nano-noble metal composite materials as described in claim 1, characterized in that, The interface Raman signal described in S1 includes first Raman characteristic peak information and first fluorescence background information. The first Raman characteristic peak information includes the number, position, width, intensity, area, and relative intensity of the first Raman characteristic peak. The intrinsic Raman signal described in S2 includes second Raman characteristic peak information and second fluorescence background information. The second Raman characteristic peak information includes the number, position, width, intensity, area, and relative intensity of the second Raman characteristic peak. The comparative analysis described in S4 includes a comparative analysis of the first Raman characteristic peak information, the second Raman characteristic peak information, the first fluorescence background information, and the second fluorescence background information.

4. The method for measuring the interfacial microstructure of polymer-based nanocomposite noble metals as described in claim 1, characterized in that, The power of the first wavelength laser and the second wavelength laser is between 1 mW and 100 mW.

5. The method for measuring the interfacial microstructure of polymer-based nano-noble metal composite materials as described in claim 1, characterized in that, The integration time of the dual-beam Raman system is between 1s and 1000s.

6. The method for measuring the interfacial microstructure of polymer-based nano-noble metal composite materials as described in claim 1, characterized in that, The wavelengths of the first wavelength laser and the second wavelength laser are selected from any two of 266nm, 325nm, 514nm, 532nm, 633nm, 785nm, 830nm and 1064nm.

7. The method for measuring the interfacial microstructure of polymer-based nano-noble metal composite materials as described in claim 1, characterized in that, The polymer substrate is selected from one or more of epoxy resin, polyimide, and silicone.

8. The method for measuring the interfacial microstructure of polymer-based nano-noble metal composite materials as described in claim 1, characterized in that, The nano-precious metal filler is selected from one or more of gold, silver and copper.

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