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Method for preparing diluted magnetic polymer dispersed liquid crystal through photo-initiated free radical tandem reaction and product thereof

A technology of dispersing liquid crystals and series reactions, applied in optics, nonlinear optics, instruments, etc., can solve problems such as the influence of liquid crystal quality and difficulty in determining the degree of change, and achieve the effects of low saturation voltage, reduced action voltage, and high contrast

Inactive Publication Date: 2022-03-08
SOUTHWEST UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, doping nanoparticles affects the microstructure of polymer-dispersed liquid crystals (PDLCs) in multiple ways, so it is difficult to determine the properties of polymer-dispersed liquid crystals (PDLCs) doped with nanoparticles may be relative to those without nanoparticles. Degree of Variation in Polymer Dispersed Liquid Crystals (PDLC)
[0004] Due to the generation of free ions during the synthesis of liquid crystals, the quality of the synthesized liquid crystals is affected

Method used

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  • Method for preparing diluted magnetic polymer dispersed liquid crystal through photo-initiated free radical tandem reaction and product thereof
  • Method for preparing diluted magnetic polymer dispersed liquid crystal through photo-initiated free radical tandem reaction and product thereof
  • Method for preparing diluted magnetic polymer dispersed liquid crystal through photo-initiated free radical tandem reaction and product thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0050] A method for preparing dilute magnetic polymer dispersed liquid crystals by light-induced free radical tandem reaction, the specific preparation method is as follows:

[0051] 1. Preparation of γ-Fe 2 o 3 Magnetic nanoparticles: (1) Preparation of FeOOH@Mg(OH) 2 Precursor: Add alkaline medium (aqueous sodium hydroxide solution with a concentration of 0.7mol / L) to FeCl at a volume ratio of 10:1 3 with Mg(NO 3 ) 2 The mixed aqueous solution (FeCl in the mixed aqueous solution 3 with Mg(NO 3 ) 2 The molar ratio is 2:1), heated to boil for 5min and then cooled to room temperature to form FeOOH@Mg(OH) by chemical precipitation 2 , with dilute HNO equivalent to 5 times the volume of the precipitate 3 Aqueous solution (concentration of 0.01mol / L) was washed until the pH value of the cleaning solution was 8, centrifuged (cleaning and separation can be repeated), dehydration, drying and grinding to obtain FeOOH@Mg(OH) 2 Precursor; (2) Preparation of γ-Fe 2 o 3 Magneti...

Embodiment 2

[0062] With the 0.04% gamma-Fe in embodiment 1 2 o 3 The volume fraction of magnetic nanoparticles becomes 0.06%, and all the other conditions are the same as in Example 1, and the same preparation obtains the intermediate product liquid crystal colloid (its specific magnetization curve is as follows: figure 1 Shown in b) and the final product dilute magnetic polymer dispersed liquid crystal (scanning electron micrograph of which is shown in Figure 4 shown).

Embodiment 3

[0064] A method for preparing dilute magnetic polymer dispersed liquid crystals by light-induced free radical tandem reaction, the specific preparation method is as follows:

[0065] 1. Preparation of γ-Fe 2 o 3 Magnetic nanoparticles: (1) Preparation of FeOOH@Mg(OH) 2 Precursor: Add alkaline medium (aqueous sodium hydroxide solution with a concentration of 0.5mol / L) to FeCl at a volume ratio of 8:1 3 with Mg(NO 3 ) 2 The mixed aqueous solution (FeCl in the mixed aqueous solution 3 with Mg(NO 3 ) 2 The molar ratio is 2:1), heated to boil for 3min and then cooled to room temperature to form FeOOH@Mg(OH) by chemical precipitation 2 , with dilute HNO equivalent to 10 times the volume of the precipitate 3 Wash with an aqueous solution (concentration of 0.005mol / L) until the pH of the cleaning solution is 8, centrifuge (cleaning and separation can be repeated), dehydrate, dry and grind to obtain FeOOH@Mg(OH) 2 Precursor; (2) Preparation of γ-Fe 2 o 3 Magnetic nanoparticl...

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Abstract

The invention relates to a method for preparing diluted magnetic polymer dispersed liquid crystal through photo-initiation free radical tandem reaction and a product thereof, and belongs to the technical field of dispersed liquid crystal preparation. The preparation method comprises the following steps: dispersing gamma-Fe2O3 magnetic nanoparticle powder wrapped by oleic acid, which is formed by gamma-Fe2O3 magnetic nanoparticles and oleic acid, into n-hexane, and dispersing and mixing formed n-hexane intermediate colloid and liquid crystal to form gamma-Fe2O3-based liquid crystal magnetic colloid; and carrying out ultraviolet irradiation polymerization reaction on the diluted magnetic polymer dispersed liquid crystal, a photoinitiator and a polymer monomer in a sample box to obtain the diluted magnetic polymer dispersed liquid crystal. According to the method, gamma-Fe2O3 magnetic nanoparticles wrapped by oleic acid are adopted to optimize the electromagnetic performance of the liquid crystal, the finally prepared polymer dispersed liquid crystal has the advantages that the scattering and absorption effects of the nanoparticles can be neglected, and the form, size and distribution of liquid crystal droplets can be kept unchanged; however, the electro-optical property of the polymer dispersed liquid crystal can be changed along with the concentration of the doped gamma-Fe2O3 magnetic nanoparticles.

Description

technical field [0001] The invention belongs to the technical field, and relates to a method for preparing dilute magnetic polymer-dispersed liquid crystal through a series reaction of free radicals induced by light and a product thereof. Background technique [0002] Liquid crystal is a liquid crystal material with orientation order but no position order formed by molecular interaction. It has been widely studied and applied because of its special physical and chemical properties. The liquid crystal is mixed with the polymer precursor (including photoinitiator and polymer monomer), and through the method of polymerization reaction, the polymer dispersed liquid crystal composite material in which micron-sized liquid crystal droplets are dispersed in the polymer matrix can be prepared. Polymer dispersed liquid crystal (PDLC) has an electro-optic effect based on light scattering characteristics, that is, under the control of applied voltage, the light intensity passing through...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F292/00C08F2/48G02F1/1334
CPCC08F292/00C08F2/48G02F1/1334
Inventor 何正红孟祥申林跃强刘晓东李建
Owner SOUTHWEST UNIVERSITY
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