CN113105766A

CN113105766A - Superhard wear-resistant transparent film material with silicon-doped carbonized polymer dots as construction elements and preparation method thereof

Info

Publication number: CN113105766A
Application number: CN202110366494.5A
Authority: CN
Inventors: 杨柏; 潘凯波; 朱志承; 乐妲; 刘崇铭; 李睿; 王静博; 韩梅
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2021-04-06
Filing date: 2021-04-06
Publication date: 2021-07-13
Anticipated expiration: 2041-04-06
Also published as: CN113105766B

Abstract

A superhard wear-resistant transparent film material which is compounded on a nanoscale and takes silicon-doped carbonized polymer dots as a construction element and a preparation method thereof belong to the technical field of superhard wear-resistant scratch-resistant transparent film material preparation. Weighing the components in a molar ratio of 1: dissolving 0.1-4 parts of propylamino silsesquioxane and citric acid in deionized water, and carrying out hydrothermal reaction at 160-200 ℃ for 3-8 hours; then naturally cooling to room temperature to obtain a light yellow transparent Si-CPDs water solution, and then filtering by using a 0.22 mu m polyethersulfone filter membrane to obtain Si-CPDs curing liquid with silicon hydroxyl on the surface; the curing liquid is coated on the surface of a glass slide processed by Plasma for 3-5 minutes in a spinning, dip-coating or spraying manner, and is cured for 0.5-3 hours at the temperature of 60-200 ℃, so that the superhard wear-resistant transparent film layer is obtained. The film material can be used for preparing hard wear-resistant protective layers on the surfaces of displays, transparent optical devices and solar cells.

Description

Superhard wear-resistant transparent film material with silicon-doped carbonized polymer dots as construction elements and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of superhard wear-resistant scratch-resistant transparent film materials, and particularly relates to a superhard wear-resistant transparent film material which is compounded on a nanoscale and takes silicon-doped carbonized polymer points as construction elements and a preparation method thereof.

Background

The optical coating has wide application in the fields of displays, transparent optical devices, solar cells and the like. Optical coatings can be divided into two broad categories: polymeric optical coatings and inorganic optical coatings. The polymer optical coating has the advantages of light weight, impact resistance, easy processing and forming and the like, but the polymer has low surface hardness and poor wear resistance. Inorganic optical coatings have high refractive index and high abrasion resistance, but have the disadvantages of high density, brittle materials, difficult processing, and the like. And the inorganic-organic hybrid material has the advantages of the two materials. Therefore, in recent years, methods for hybridizing polymer coatings with inorganic nanoparticles have been continuously explored.

The pencil hardness of the currently applied organic-inorganic hybrid wear-resistant optical coating is below 6H, and the optical coating is difficult to resist repeated friction of steel wool, so that the use requirement of the optical protective coating cannot be well met. Therefore, the design and preparation of transparent coatings with ultrahard, wear-resistant and scratch-resistant properties are the problems to be solved at present.

Recently, carbonized polymer dots have been receiving much attention due to their advantages of excellent water solubility, low cost, easy preparation, and strong designability. The carbonized polymer dots are used as nano particles with a core-shell structure with the size less than 15nm, the nano particles are used as construction elements, and the mechanical property of the inorganic-organic hybrid optical thin film material is enhanced through the adjustment and control of a cross-linking structure in the silicon-doped core and the reactive active sites on the surface of the shell, so that the problems are hopeful to be solved.

Disclosure of Invention

The invention aims to provide a superhard wear-resistant transparent film material taking silicon-doped carbonized polymer dots as a construction element and a preparation method thereof. The organic-inorganic hybrid film material has good film forming property and uniform optical property, and the highest pencil hardness can reach 9H under the load of 1 Kg; under the load of 0.2Kg, the steel wool after 4000 times of repeated friction does not generate scratches. Therefore, the coating has practical application value in the aspect of wear-resistant and scratch-resistant film layers of optical devices.

The invention relates to a preparation method of a superhard wear-resistant transparent film layer with silicon-doped carbonized polymer dots as a construction element, which comprises the following steps:

(1) preparation of Si-CPDs by hydrothermal method

Weighing a mixture with a molar ratio of 1: dissolving 0.1-4 parts of propylamino silsesquioxane and citric acid in deionized water, and stirring until the materials are completely dissolved; transferring the obtained mixed solution into a polytetrafluoroethylene lined reaction kettle, and screwing the mixed solution to be completely sealed; placing the reaction kettle in an oven at 160-200 ℃ for reaction for 3-8 hours; then taking out the reaction kettle and naturally cooling to room temperature to obtain a light yellow transparent Si-CPDs water solution, and then filtering by using a 0.22 mu m polyethersulfone filter membrane to obtain a Si-CPDs solidified solution; cracking Si-O-Si of aminopropyl siloxane at high temperature and high pressure to form silicon hydroxyl, dehydrating, condensing and carbonizing amino and carboxyl to form a cross-linked carbonized structure, and finally forming Si-CPDs with silicon hydroxyl on the surface, wherein the structure of the amino siloxane is shown as a formula (I):

for convenience of explanation of the specific formation of the carbonized polymer dots, octaaminosilsesquioxane (formula I-1) and citric acid are exemplified (the reaction of other aminosilicones with citric acid is similar), the reaction principle of which is as shown in formula (II):

(2) obtaining a composite film layer by coating and curing

Spin coating, dip coating or spray coating the solution of Si-CPDs nano particles with silicon hydroxyl groups on the surface obtained in the step (1) on the surface of a glass slide treated by Plasma for 3-5 minutes, and curing at 60-200 ℃ for 0.5-3 hours to obtain a superhard wear-resistant scratch-resistant superhard wear-resistant transparent film layer with silicon-doped carbonized polymer points as a construction element, wherein the curing process is shown as a formula (III).

Drawings

Fig. 1 (a): transmission electron micrographs of Si-CPDs; fig. 1 (b): particle size histogram of Si-CPDs.

FIG. 2: is a Fourier infrared spectrogram of the ultrahard wear-resistant transparent film layer (namely the cured film 1 in the figure) which is composed of octa-amino silsesquioxane, Si-CPDs and silicon-doped carbonized polymer points as building elements.

FIG. 3: transmission spectrum of cured film 1 in example 1.

FIG. 4: cured film 1 element profile in example 1.

Fig. 5 (a): an optical micrograph of the cured film 1 of example 1 after the 9H pencil hardness test; fig. 5 (b): optical microscope photograph of cured film 7 of comparative example 1 after 2H pencil hardness test.

Fig. 6 (a): optical micrographs of the cured film 1 of example 1 after being rubbed with

steel wool

500, 1000, 2000, and 4000 times, respectively; fig. 6 (b): the optical microscope photographs of the cured film 7 in comparative example 1 were taken after 500, 1000, 2000, and 4000 steel wool rubs, respectively.

Table 1: performance data for cured films prepared in examples and comparative examples

Sample name	Film thickness/. mu.m	Light transmittance (550nm)	Hardness of pencil	Steel wool resistance test
					Cured film 1	52	99.2％	9H	4000 times of no trace
Cured film 2	45	99.5％	8H	2000 times no trace
					Cured film 3	61	99.1％	8H	2000 times no trace
Cured film 4	42	99.7％	6H	No trace for 1000 times
					Cured film 5	47	99.3％	9H	4000 times of no trace
Cured film 6	53	99.0％	9H	4000 times of no trace
					Cured film 7	55	99.6％	1H	500 severe marks
Cured film 8	61	99.2％	5H	500 severe marks

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the present invention is not limited thereto.

Example 1

Octapropylamino silsesquioxane (2.2g, 2.5mmol) and citric acid (0.72g, 3.75mmol) were weighed out and dissolved in 10mL of deionized water and stirred until completely dissolved. The resulting mixed solution was transferred to a 25mL teflon lined reactor and screwed to seal completely. The reaction kettle is placed in an oven at 180 ℃ and reacted for 5 hours. Then taking out the reaction kettle and naturally cooling to room temperature to obtain light yellow transparent Si-CPDs aqueous solution. Filtering the obtained Si-CPDs aqueous solution with a 0.22 mu m polyethersulfone filter membrane to obtain Si-CPDs curing solution 1, and directly coating and curing the solution or freeze-drying the solution to obtain dry powder for storage. When in use, the coating is dissolved in water again for coating and curing.

The slides were plasma treated (3 min) to make their surfaces hydrophilic. Sucking the Si-CPDs curing solution 1, uniformly coating the solution on the surface of a glass slide, transferring the glass slide to a 60 ℃ hot stage, drying and pre-curing the glass slide for 30 minutes, raising the temperature to 150 ℃ after solvent water is volatilized to be dry, and curing the glass slide for 2 hours. A yellowish transparent cured film 1 was obtained, and the respective performance data are shown in Table 1.

The morphology of the prepared Si-CPDs is quasi-spherical through observation of a transmission electron microscope, the average size of the Si-CPDs is 4.5nm, the size distribution of the Si-CPDs is 3-6.5 nm, and the Si-CPDs have good monodispersity (figure 1(a) and figure 1 (b)). By characterizing the infrared spectra of octapropylamino silsesquioxane, Si-CPDs1 and cured film 1 (FIG. 2), it was shown that abundant groups including hydroxyl, carbonyl, amide bonds, etc. were present in Si-CPDs. The starting material octapropylamino silsesquioxane I can be found_Si-OH/I_Si-O-Si＝I₉₃₀/I₁₁₃₅0.3857, carbonized polymer point I_Si-OH/I_Si-O-Si＝I₉₃₀/I₁₁₃₅0.6207, which shows that the content of silicon hydroxyl groups increases by the hydrothermal reaction. After thermal curing, I of the cured coating_Si-OH/I_Si-O-Si＝I₉₃₀/I₁₁₃₅0.4769, the silicon hydroxyl content decreases. The light transmittance of the cured film 1 is characterized (fig. 3), the light transmittance is over 99% at 500-900nm, the light transmittance is lower than 60% at 300-400nm, and the cured film 1 has the light absorption characteristic in the ultraviolet A region. The element distribution of the cured film is represented by an energy spectrum, and the uniform distribution of elements such as carbon, nitrogen, oxygen, silicon and the like on the film can be seen, which indicates that the film is inorganic-organic homogeneous hybridization (figure 4). The cured film 1 was tested for pencil hardness (FIG. 5(a)), and no scratch occurred at 9H. Comparative example the pencil hardness of the cured film appeared severe at 2HHeavy scratch (fig. 5 (b)). The film layer was tested for steel wool rub resistance, and cured film 2 was not scratched after 4000 cycles under a load of 200g (fig. 6 (a)). The cured film of comparative example was subjected to 500 cycles, and severe scratches were formed on the surface (FIG. 6 (b)).

Example 2

Octopropylamino silsesquioxane (2.2g, 2.5mmol) was weighed out. Citric acid (0.48g, 2.5mmol) was dissolved in 10mL of deionized water and stirred to dissolve completely. The resulting mixed solution was transferred to a 25mL teflon lined reactor and screwed to seal completely. The reaction kettle is placed in an oven at 180 ℃ and reacted for 5 hours. Then taking out the reaction kettle and naturally cooling to room temperature to obtain light yellow transparent carbonized polymer dot aqueous solution. Filtering the obtained Si-CPDs aqueous solution by using a polyethersulfone filter membrane with the diameter of 0.22 mu m to obtain Si-CPDs curing solution 2; the coating film was cured in the same manner as in example 1 to obtain cured film 2, and the respective property data are shown in Table 1.

Example 3

Octopropylamino silsesquioxane (2.2g, 2.5mmol) was weighed out. Citric acid (0.145g, 0.8mmol) was dissolved in 10mL of deionized water and stirred to dissolve completely. The resulting mixed solution was transferred to a 25mL teflon lined reactor and screwed to seal completely. The reaction kettle is placed in an oven at 180 ℃ and reacted for 5 hours. Then taking out the reaction kettle and naturally cooling to room temperature to obtain light yellow transparent carbonized polymer dot aqueous solution. Filtering the obtained carbonized polymer dot aqueous solution by using a polyether sulfone filter membrane with the diameter of 0.22 mu m to obtain Si-CPDs curing liquid 3; the coating film was cured in the same manner as in example 1 to obtain a cured film 3, and the respective property data are shown in Table 1.

Example 4

Hexapropylamino silsesquioxane (1.65g, 2.5mmol) and citric acid (0.54g, 2.81mmol) were weighed out and dissolved in 10mL of deionized water, and stirred to dissolve completely. The resulting mixed solution was transferred to a 25mL teflon lined reactor and screwed to seal completely. The reaction kettle is placed in an oven at 180 ℃ and reacted for 5 hours. Then taking out the reaction kettle and naturally cooling to room temperature to obtain light yellow transparent Si-CPDs aqueous solution. Filtering the obtained Si-CPDs aqueous solution by using a polyethersulfone filter membrane with the diameter of 0.22 mu m to obtain Si-CPDs curing solution 4; the coating film was cured in the same manner as in example 1 to obtain a cured film 4, and the respective property data are shown in Table 1.

Example 5

Tetraaminopropylcyclotetrasilanol (1.19g, 2.5mmol) citric acid (0.36g, 1.88mmol) was weighed out and dissolved in 10mL of deionized water, and stirred to dissolve completely. The resulting mixed solution was transferred to a 25mL teflon lined reactor and screwed to seal completely. The reaction kettle is placed in an oven at 180 ℃ and reacted for 5 hours. Then taking out the reaction kettle and naturally cooling to room temperature to obtain light yellow transparent Si-CPDs aqueous solution. Filtering the obtained Si-CPDs aqueous solution by using a polyethersulfone filter membrane with the diameter of 0.22 mu m to obtain Si-CPDs curing solution 5; the coating film was cured in the same manner as in example 1 to obtain a cured film 5, and the respective property data are shown in Table 1.

Comparative example 1

Octapropylamino silsesquioxane (2.2g, 2.5mmol) was weighed out and dissolved in 10mL of deionized water, and stirred to be completely dissolved. The resulting mixed solution was transferred to a 25mL teflon lined reactor and screwed to seal completely. The reaction kettle is placed in an oven at 180 ℃ and reacted for 5 hours. Then taking out the reaction kettle and naturally cooling to room temperature to obtain colorless and transparent Si-CPDs aqueous solution. The obtained Si-CPDs aqueous solution is filtered by a polyethersulfone filter membrane with the diameter of 0.22 mu m to obtain the Si-CPDs curing solution 7.

The slides were plasma treated (3 min) to make their surfaces hydrophilic. Absorbing the Si-CPDs curing solution 7, uniformly coating the solution on the surface of the glass slide, transferring the glass slide to a 60 ℃ hot stage, drying and pre-curing the glass slide for 30 minutes, raising the temperature to 150 ℃ after solvent water is volatilized to be dry, and curing the glass slide for 2 hours. A colorless and transparent cured film 7 was obtained, the properties of which are shown in Table 1.

Comparative example 2

Octapropylamino silsesquioxane (2.2g, 2.5mmol) and citric acid (0.72g, 3.75mmol) were weighed out and dissolved in 10mL of deionized water, and stirred to be completely dissolved, thereby obtaining a solidified solution 8. The slides were plasma treated (3 min) to make their surfaces hydrophilic. Absorbing the curing liquid 8, uniformly coating the curing liquid on the surface of the glass slide, transferring the glass slide to a hot table at 60 ℃, drying and pre-curing the glass slide for 30 minutes, raising the temperature to 150 ℃ after solvent water is volatilized to be dry, and curing the glass slide for 2 hours. A yellowish, transparent cured film 8 was obtained, the properties of which are shown in Table 1.

Claims

1. A method for preparing a superhard wear-resistant transparent film layer with silicon-doped carbonized polymer dots as a construction element comprises the following steps:

(1) preparation of Si-CPDs by hydrothermal method

Weighing a mixture with a molar ratio of 1: dissolving 0.1-4 parts of propylamino silsesquioxane and citric acid in deionized water, and stirring until the materials are completely dissolved; transferring the obtained mixed solution into a polytetrafluoroethylene lined reaction kettle, and screwing the mixed solution to be completely sealed; placing the reaction kettle in an oven at 160-200 ℃ for reaction for 3-8 hours; then taking out the reaction kettle and naturally cooling to room temperature to obtain light yellow transparent Si-CPDs aqueous solution, and then filtering with a 0.22 mu m polyethersulfone filter membrane to obtain Si-CPDs curing liquid with silicon hydroxyl on the surface;

(2) obtaining a composite film layer by coating and curing

And (2) spin-coating, dip-coating or spray-coating the Si-CPDs curing liquid with the surface containing silicon hydroxyl groups obtained in the step (1) on the surface of a glass slide treated by Plasma for 3-5 minutes, and curing at 60-200 ℃ for 0.5-3 hours to obtain the superhard wear-resistant and scratch-resistant superhard wear-resistant transparent film layer with silicon-doped carbonized polymer points as construction elements.

2. The method for preparing a superhard wear-resistant transparent film layer using silicon-doped carbonized polymer dots as a construction element according to claim 1, wherein the method comprises the following steps: the structure of the aminosilicone is shown in one of the following,

3. a superhard wear-resistant transparent film layer with silicon-doped carbonized polymer dots as a construction element is characterized in that: is prepared by the method of claim 1 or 2.