CN107903363B

CN107903363B - Polydimethylsiloxane hollow nano-microsphere and preparation method and application thereof

Info

Publication number: CN107903363B
Application number: CN201711172189.2A
Authority: CN
Inventors: 丁晓莉; 谭芳芳; 王鑫兰; 李晓峰; 赵红永; 张玉忠
Original assignee: Tianjin Polytechnic University
Current assignee: Tianjin Polytechnic University
Priority date: 2017-11-21
Filing date: 2017-11-21
Publication date: 2020-07-28
Anticipated expiration: 2037-11-21
Also published as: CN107903363A

Abstract

The invention relates to a nano material, in particular to a polydimethylsiloxane hollow nano microsphere, a preparation method and an application thereof, wherein the preparation process can be carried out according to the following method: polymerizing the oil-soluble polydimethylsiloxane prepolymer in the water-in-oil microemulsion, reacting for a certain time, and removing an oil phase solvent, a surfactant, water and the like to obtain the polydimethylsiloxane hollow nano-microsphere. The polydimethylsiloxane hollow nano-microsphere can be used for preparing gas separation membranes and pervaporation membranes.

Description

Polydimethylsiloxane hollow nano-microsphere and preparation method and application thereof

Technical Field

The invention relates to a nano technology and a high molecular technology, in particular to a polydimethylsiloxane hollow nano microsphere and a preparation method and application thereof.

Background

In order to increase the permeability of the gas separation membrane and the pervaporation membrane, the thickness of the separation membrane should be minimized. The addition of hollow microspheres in the membrane, which is equivalent to the reduction of the actual thickness of the membrane under the condition of a certain apparent thickness of the membrane, is a potential method for reducing the thickness of the separation membrane. However, in order to ensure that the gas passes through the hollow microsphere phase, the shell of the microsphere has a lower resistance than the matrix material, i.e., the intrinsic permeability coefficient of the material of the shell of the microsphere is greater than that of the matrix material. Polydimethylsiloxane is a rubbery material with a very large permeability coefficient and is widely applied in the fields of gas membrane separation and pervaporation. The permeability coefficient of the composite membrane is far higher than that of common glassy polymers, so that the composite membrane is very suitable for preparing hollow nano microspheres and is used for preparing gas separation hybrid membranes and pervaporation hybrid membranes. The invention mainly relates to polydimethylsiloxane hollow nano-microspheres prepared by a simple method and application thereof: namely, polydimethylsiloxane prepolymer, catalyst and cross-linking agent are directly added into the microemulsion, hollow nano microspheres are synthesized through cross-linking reaction, and the microspheres are blended with other polymers to prepare a membrane. The method is simple, has few steps, and can be used for gas separation membranes and pervaporation membranes.

Disclosure of Invention

The invention aims to provide polydimethylsiloxane hollow nano-microspheres which can be prepared by a simple method, and a preparation method and application thereof. The preparation scheme is as follows:

1) mixing the oil phase solvent with a certain amount of water, a certain amount of surfactant and a certain amount of cosurfactant to form water-in-oil type microemulsion;

2) dissolving a certain amount of polydimethylsiloxane prepolymer, a crosslinking agent and a catalyst in the microemulsion prepared in the step 1), and stirring to dissolve the polydimethylsiloxane prepolymer, the crosslinking agent and the catalyst; after reacting for a period of time, removing the surfactant, the solvent, the cosurfactant and the water to obtain the hollow nano-microsphere.

The content of the polydimethylsiloxane prepolymer is 0.1-10 wt% of the microemulsion oil phase solvent. The oil phase solvent comprises n-hexane, n-pentane, petroleum ether, n-heptane, toluene and cyclohexane. The surfactant may be present in an amount of 0.

The obtained hollow nano-microsphere is used as a dispersion phase to be blended with other polymers, and can be used for preparing gas separation membranes and pervaporation membranes.

The invention has the following advantages: hollow nano microspheres are generated by reaction in a microemulsion system, and the sizes of the microspheres are uniform. The polymer microsphere is used as a disperse phase, and the compatibility between the disperse phase and a matrix is better. The microspheres prepared from polydimethylsiloxane have high permeability coefficient.

Drawings

FIG. 1 Transmission Electron micrograph of hollow Nanownstrobes prepared with SY L GARD184 in example 1

FIG. 2 Electron micrograph of membrane prepared by hollow nanometer microsphere/polysulfone blending machine in example 3

Detailed Description

Example 1

Adopting Dow Corning SY L GARD184 silicon rubber suite, preparing water, n-hexane solution and isopropanol into microemulsion according to the mass ratio of 0.1: 0.48: 0.5, adding a component A (10 wt% of n-hexane) and a component B (10 wt% of the component A) in the SY L GARD184 suite, reacting for 4h, removing a solvent, a cosurfactant and water, and drying to obtain the hollow nano-microsphere.

Mixing the microsphere with a certain amount of methoxypolyethylene glycolUniformly mixing acid ester (PEGMEA), a certain amount of cross-linking agent (the mass ratio of the monomer to the cross-linking agent is 10: 1) and 100ppm of initiator (1-hydroxycyclohexyl phenyl ketone), defoaming, placing on a quartz glass plate, exposing the quartz glass plate to ultraviolet light for a certain time, and crosslinking to obtain a solid film. The separation membrane performance is shown in table 1. CO compared to when no microspheres are added₂The permeation rate is increased by 2-5 times, and the separation coefficient is not changed greatly.

TABLE 1

Crosslinking agent	CO₂Coefficient of permeability (10)^-7cm³(STP)·cm·cm^-2·s^-1·cmHg^-1)	CO₂/N₂Coefficient of separation
			Dipentaerythritol triacrylate	5.12	34.73
Dipentaerythritol tetraacrylate	7.53	38.79
			Dipentaerythritol pentaacrylate	1.89	45.32
Dipentaerythritol hexaacrylate	9.56	35.30

Example 2

A mezzanine RTV615 silicone rubber kit was used. Preparing water, n-heptane solution, sodium dodecyl sulfate and n-butanol into microemulsion; adding the component A (5 wt% of n-heptane) and the component B (10 wt% of the component A) in the kit, reacting for 2h, removing the surfactant, the solvent, the cosurfactant and the water, and drying to obtain the microspheres. Dispersing the microspheres in ethanol, placing the microspheres in a petri dish, and evaporating to remove the ethanol to obtain the polydimethylsiloxane hollow microsphere membrane. O is₂Permeability coefficient 9 × 10^-7cm³(STP)·cm·cm^-2·s^-1·cmHg^-1The density of the film is improved by 9 times compared with that of polydimethylsiloxane₂/N₂The separation coefficient is 3.33, which is improved by 70 percent compared with a polydimethylsiloxane dense homogeneous film.

Example 3

A certain amount of polydimethylsiloxane hollow nanospheres (prepared in example 1) were doped into polysulfone to prepare a separation membrane.

Testing the gas separation performance: o is₂Permeability coefficient 2 × 10^-8cm³(STP)·cm·cm^-2·s^-1·cmHg^-1Is improved by 150 times than the polysulfone dense homogeneous film, O₂/N₂The separation coefficient is 4.3, which is reduced by 23 percent compared with the polysulfone dense homogeneous membrane.

Example 4

Dissolving a certain amount of alpha cellulose in N-methylmorpholine oxide to prepare a 12 wt% solution, adding a certain amount of polydimethylsiloxane hollow nano-microspheres (prepared in example 2), uniformly mixing to prepare a membrane solution, defoaming, coating the membrane solution on a cellulose acetate porous basement membrane, curing in water to form a membrane, drying, and performing pervaporation under the conditions of a downstream vacuum degree of 5mmHg absolute negative pressure, a cold well condensation and collection, an upstream operating temperature of 35 ℃ and a feeding solution of 10 wt% isopropanol aqueous solution (2L min.)^-1). The properties are shown in Table 2.

TABLE 2

The above examples do not indicate a limited scope of application of the patent. Any person skilled in the art can easily apply the teachings of the patent to any other possible system.

Claims

1. A preparation method of polydimethylsiloxane hollow nano-microspheres is characterized by comprising the following steps:

preparing microemulsion by water, normal hexane and isopropanol according to the mass ratio of 0.1: 0.48: 0.5, adding the component A and the component B in the SY L GARD184 suite, reacting for 4h, removing the normal hexane, the isopropanol and the water, and drying to obtain hollow nano microspheres;

the dosage of the component A in the adding kit is 10 wt% of n-hexane; component B was used in an amount of 10 wt% of component A.