Preparation And Application Of Fluoropolymer With Special Structure Based Via Emulsion Template Method

Emulsion template method can be used to prepare special structural materials?such as porous materials,hollow microsphere materials?,which has attracted people's attention because of its superb advantages such as simple method,controllable and adjustable material structure.These materials are being used in chemical industries?such as catalyst carriers,chemical reagent carriers,etc.?,pharmaceuticals?such as immobilization and separation of enzymes and proteins?,environmental protection?such as gas adsorbents,purification of water pollutants,etc.?,special functional materials?such as energy storage materials,thermal insulation materials,sound insulation materials?and so on.The low polarity and strong electronegativity of the fluorine atoms gives the fluoropolymers with many excellent properties,such as low surface energy,high heat resistance,good chemical stability,etc.If the fluoropolymer material is functionalized by special structure,the porous material or hollow microsphere material not only retains the inherently excellent surface properties of the fluorine-containing material,but also gives its structural characteristics,which greatly expands the application range of the fluoro-materials.However,the preparation of high-performance fluorine-containing structural materials using the emulsion template method has been a challenge due to the lack of suitable surfactants to stabilize the fluorine-containing high internal phase emulsions.Based on this cause,the research was conducted for the simple and efficient preparation of special structural fluorine-containing materials by the emulsion template method,combining the performance advantages of fluorine-containing materials.In this research,commercial surfactants,self-assembled amphiphilic fluorine-containing macromolecular surfactants,and nanoparticle to stabilize emulsions were explored.The preparation and application of materials under various conditions were also done.The main research content of the paper includes the following sections:?1?In the first section,a suitable commercial surfactant Hypermer-B246,was selected as stabilizer for preparation of highly viscous fluorine-containing w/o high internal phase emulsion system with 2,2,2-trifluoroethyl methacrylate?TFEMA?as a main monomer,and divinylbenzene?DVB?as crosslinker.This part explored the effect of crosslinker DVB ratio in oil phase,the concentration of surfactant Hypermer-B246,the volume of water dispersed phase on the size of the emulsion droplet,and the structure and morphology of the porous material.The state of the emulsion was observed using an optical microscope during the experiment and the structure of the pores of the material was characterized by scanning electron microscopy?SEM?.The water contact angle test showed the material owned excellent hydrophobicity,and the weight loss test and acid and alkali resistance test proved that the material had excellent thermal properties as well as chemical resistance.The prepared porous fluorine-containing materials were used for oil-water separation application.The results showed that the materials exhibited rapid adsorption effects on various organic solvents,and the saturated adsorption capacity was up to 10.5 times the weight of the materials themselves.Meanwhile,the material was utilized cyclically after 10 times by adsorption-centrifugal separation,it still maintained a high adsorption capacity.?2?In second section,fluorine-containing porous materials were prepared by synthesizing amphiphilic fluorine-containing block macromolecular surfactant to stabilize high internal phase emulsions.The macromolecular surfactant mPEG_5k-b-PHFBMA-CTA was successfully demonstrated by using thermogravimetry?TGA?test,gel permeation chromatography?GPC?and nuclear magnetic resonance?¹H NMR?analysis.The experimental results showed that the concentrations of amphiphilic fluoropolymer macromolecular surfactant,the length of hydrophobic fluorine-containing segment PHFBMA,and the place where the water-soluble and oil-soluble initiators are located had great influence on the structure of porous materials.Then the water contact angle test and the water absorption experiments were used to analyze the pore surface hydrophilicity compared with those of prepared with Hypermer-B246.The mechanical properties of porous materials prepared under different conditions were also tested.?3?In third section,fluorine-containing hollow microspheres were prepared using a single nano-silica particle to stabilize multiple Pickering fluorinated emulsions.First,the influencing conditions for preparation of multiple Pickering fluorinated emulsions were explored,such as oil-water volume ratio,nano-silica concentration,basic salts,neutral salts,acidic salts solution and their concentrations in the aqueous phase.As a result,acidic salts and neutral salts solution were capable to form stable multiple Pickering emulsion but basic salts solution were not stable.With increasing of the concentration of nano-silica particle from 0.5wt%to 1.5wt%,size of multiple Pickering emulsion droplet was reduced.Fluoro-containing hollow microspheres were successfully prepared after polymerization.