Preparation method of composite particles with hairy structures on surfaces
阅读说明：本技术 一种表面具有多毛结构的复合颗粒的制备方法 (Preparation method of composite particles with hairy structures on surfaces ) 是由 杨振忠 万基平 梁福鑫 于 2019-04-24 设计创作，主要内容包括：本发明公开了一种表面具有多毛结构的复合颗粒的制备方法。所述制备方包括如下步骤：1)将无机纳米颗粒分散于有机溶剂中；2)向步骤1)的体系中加入引发剂和单体,所述单体进行阳离子聚合,即在所述无机纳米颗粒表面生成聚合物纳米纤维,至此即得到所述复合颗粒。本发明所提供的表面具有多毛结构的复合颗粒的制备方法,是通过阳离子沉淀聚合的方法,利用无机纳米颗粒表面的官能团对阳离子的淬灭作用,原位在颗粒表面生长聚合物纳米纤维。本发明方法,无机纳米颗粒的适用范围广,聚合物纤维的组成和形貌可以通过反应条件来控制。(The invention discloses a preparation method of composite particles with a hairy structure on the surface. The preparation method comprises the following steps: 1) dispersing inorganic nanoparticles in an organic solvent; 2) adding an initiator and a monomer into the system obtained in the step 1), and carrying out cationic polymerization on the monomer to generate polymer nano fibers on the surface of the inorganic nano particles, thereby obtaining the composite particles. The preparation method of the composite particle with the hairy structure on the surface provided by the invention is to grow the polymer nanofiber on the surface of the particle in situ by a cationic precipitation polymerization method and by utilizing the quenching effect of functional groups on the surface of inorganic nanoparticles on cations. The method has wide application range of the inorganic nano particles, and the composition and the appearance of the polymer fiber can be controlled by reaction conditions.)
1. A method for preparing composite particles with a hairy structure on the surface comprises the following steps:
1) dispersing inorganic nanoparticles in an organic solvent;
2) adding an initiator and a monomer into the system obtained in the step 1), and carrying out cationic polymerization on the monomer to generate polymer nano fibers on the surface of the inorganic nano particles, thereby obtaining the composite particles.
2. The method of claim 1, wherein: in the step 1), the inorganic nanoparticles are silica nanoparticles or ferroferric oxide nanoparticles.
3. The production method according to claim 1 or 2, characterized in that: in the step 1), the organic solvent is alkane;
dispersing the inorganic nanoparticles in the organic solvent under the action of a surfactant.
4. The production method according to claim 3, characterized in that: the surfactant is Span-80;
the volume concentration of the surfactant in the organic solvent is 0.5-5 per mill.
5. The production method according to any one of claims 1 to 4, characterized in that: in step 2), the cationic polymerization is carried out under stirring or ultrasound.
6. The production method according to any one of claims 1 to 5, characterized in that: in the step 2), the initiator is boron trifluoride diethyl etherate;
the volume concentration of the boron trifluoride diethyl etherate in the system is 0.5-5 per mill;
the temperature of the cationic polymerization is-78-60 ℃.
7. The production method according to any one of claims 1 to 6, characterized in that: in the step 2), the monomer is a monomer A, and the monomer A is divinylbenzene, styrene, benzyl chlorostyrene, methyl styrene or tert-butyl styrene;
the volume concentration of the monomer A in the system is 1-5%;
the time of the cationic polymerization is 30 s-20 min.
8. The production method according to any one of claims 1 to 6, characterized in that: in the step 2), the monomer comprises a monomer A and a monomer B, and the monomer A and the monomer B are sequentially added into the system;
the monomer A and the monomer B are divinylbenzene, styrene, benzyl chlorostyrene, methyl styrene or tert-butyl styrene which are different from each other;
The time for the cationic polymerization of the monomer A and the monomer B is 30 s-20 min.
9. Composite particles prepared by the process of any one of claims 1 to 8.
Technical Field
The invention relates to a preparation method of composite particles with a hairy structure on the surface, and belongs to the technical field of high polymer nano materials.
Background
Hairy structures are very common in Nature and can impart specific properties to organisms such as sensing (J.CellSci.,2010,123, 499-. For example, the water strider leg is distributed with a large number of long and thin bristles with a multi-scale structure, which can prevent water drops from infiltrating, and the water strider leg is macroscopically super-hydrophobic, so that the water strider can quickly walk or run on the water surface. The gecko has super strong adhesion force from a large number of micron-sized bristles on the sole, the tail ends of the bristles are forked to form hundreds of finer shovel-shaped villi, and the multi-scale fibrous surface structure can form super strong adhesion force with a substrate, so that the gecko can crawl on vertical walls and ceilings.
Inspired by the nature, scientists have conducted intensive research on the bionic hairy structure. Most of the reported hairy structures are composed of carbon nanotubes or one-dimensional inorganic nanomaterials, which can be prepared by chemical vapor deposition (adv. mater, 2010,22, 1654-doped 1658), hydrothermal method (adv. mater, 2010,22, 1654-doped 1658), solvothermal (Soft Matter,2009,5, 4687-doped 4697) and the like. However, the conditions for these preparation methods are relatively severe, and high temperature or high pressure is generally required. The polymer hairy structure is mainly prepared by a template method (Proc. Natl. Acad. Sci. USA,2009,106, 5639-152 44; J. colloid Interface Sci. 2012,372, 231-238). However, the template method is complicated in preparation process, cannot be used for large-scale preparation, and is not suitable for preparing hairy structures on curved surfaces. Therefore, the development of a simple and feasible method for mass production of polymer hairy structures is a problem that researchers have paid great attention to and have not been able to solve well, and further research is urgently needed.
Disclosure of Invention
The invention aims to provide a preparation method of composite particles with hairy structures on the surfaces, which has mild reaction conditions and high reaction speed and can be prepared in large batch.
The preparation method of the composite particle with the hairy structure on the surface provided by the invention is to grow the polymer nanofiber on the surface of the particle in situ by a cationic precipitation polymerization method and by utilizing the quenching effect of functional groups on the surface of inorganic nanoparticles on cations.
The method has wide application range of the inorganic nano particles, and the composition and the appearance of the polymer fiber can be controlled by reaction conditions.
Specifically, the preparation method of the composite particle with the hairy structure on the surface comprises the following steps:
1) dispersing inorganic nanoparticles in an organic solvent;
2) adding an initiator and a monomer into the system obtained in the step 1), and carrying out cationic polymerization on the monomer to generate polymer nano fibers on the surface of the inorganic nano particles, thereby obtaining the composite particles.
The composite particles prepared by the method consist of the inorganic nanoparticles and the polymer nanofibers, and the polymer nanofibers are uniformly distributed on the surfaces of the inorganic nanoparticles, wherein the diameter of the polymer nanofibers is 50-100 nm, the length of the polymer nanofibers is 0-2 microns, but not zero.
The principle of the method for preparing the composite nano-particles is as follows: under the action of the initiator, the monomer is subjected to cationic polymerization, is precipitated from the solution and is deposited on the surface of the inorganic nano-particles, so that a polymer thin layer is formed on the surface of the particles. As the reaction proceeds, the initiator phase separates from the polymer and the internal stresses in the polymer shell cause the initiator to be extruded as small droplets onto the polymer surface. And the initiator liquid drop continuously initiates the monomer to grow to form the nano-fiber, so as to obtain the composite particle with the hairy structure.
In the preparation method, in the step 1), the inorganic nanoparticles are silica nanoparticles or ferroferric oxide nanoparticles;
the silica nanoparticles may have a particle size of 200nm to 10 μm, such as 1.5 μm;
the particle size of the ferroferric oxide nano particles can be 200 nm-400 nm, such as 300 nm.
In the above preparation method, in step 1), the organic solvent is alkane; the alkane can be n-hexane or n-heptane;
dispersing the inorganic nanoparticles in the organic solvent under the action of a surfactant.
In the preparation method, the surfactant is Span-80 (Span 80);
the volume concentration of the surfactant in the organic solvent is 0.5-5 per mill.
In the above preparation method, in the step 2), the cationic polymerization is performed under stirring or ultrasound.
In the preparation method, in the step 2), the initiator is boron trifluoride ethyl ether (BFEE);
the volume concentration of the boron trifluoride diethyl etherate in the system is 0.5-5 per mill;
the cationic polymerization is carried out at a temperature of-78 ℃ to 60 ℃, for example, at room temperature.
In the above preparation method, in step 2), the monomer is a monomer a, and the monomer a is divinylbenzene, styrene, benzyl chlorostyrene, methylstyrene or tert-butylstyrene, that is, a monomer is adopted to polymerize to generate a homopolymer nanofiber;
The volume concentration of the monomer A in the system is 1-5%;
the time of the cationic polymerization is 30 s-20 min.
In the preparation method, in the step 2), the monomer comprises a monomer A and a monomer B, and the monomer A and the monomer B are sequentially added into the system, namely two different monomers are adopted for polymerization;
the monomer A and the monomer B are both Divinylbenzene (DVB), styrene (St), benzyl chlorostyrene (VBC), methylstyrene (MSt) or tert-butylstyrene (tSt), and are different, thereby copolymerizing to produce nanofibers of a block copolymer;
the volume concentration of the monomer A in the system is 1-5%;
the volume concentration of the monomer B in the system is 0-5% but not zero;
the time for the cationic polymerization of the monomer A and the monomer B is 5-20 min, preferably 5-10 min, 5min or 10 min.
In the composite particle with the hairy structure prepared by the invention, the mass fraction of the inorganic nano-particles is 10-50%, such as 25-40%, 25%, 30% or 40%.
The composite particles prepared by the method have super-hydrophobic and super-oleophylic characteristics, and can be used for separating oil-water mixtures.
The preparation method of the composite particle with the hairy structure on the surface, provided by the invention, is that the polymer nanofiber grows on the surface of the inorganic nanoparticle in situ through cationic precipitation polymerization, and the method has the following advantages:
1. the method has mild reaction conditions, can be used for reaction at room temperature, and is easy for batch preparation
2. The reaction speed is high, and the reaction is completed within 30 min.
3. The method has strong universality and the composition of the particles and the fibers can be adjusted.
Drawings
FIG. 1 is SiO2Electron micrograph of microspheres.
FIG. 2 shows the composite microsphere PDVB @ SiO prepared in example 12Electron micrograph of (a).
FIG. 3 is Fe3O4Electron micrograph of microspheres.
FIG. 4 shows the magnetic hairy microsphere PVBC-PDVB @ Fe prepared in example 43O4Electron micrograph of (a).
FIG. 5 shows the magnetic hairy microsphere PVBC-PDVB @ Fe prepared in example 4 of the present invention3O4Photograph for oil-water separation (left image is oil-water mixture, right image is separated photograph).
Detailed Description
The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.
Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.
The ferroferric oxide microspheres used in the following examples are prepared according to the following method:
5.4g FeCl3·6H2O stirred and dispersed in 200mL of ethylene glycol with sonication, followed by the addition of 14.4g of sodium acetate and sonication for about 30min, gave a yellow homogeneous solution.
It was transferred to a Teflon lined autoclave and reacted at 200 ℃ for 12 h. Naturally cooling, magnetically separating, washing with water and ethanol for 3 times, and vacuum drying at 45 deg.C for 12 hr to obtain black product.
The particle size was about 250nm, paramagnetic and the magnetic saturation was 76.67 emu/g.
FIG. 3 shows the magnetic particles Fe prepared3O4Electron micrograph of (a).