Preparation Of PVDF Hollow Fiber Membrane By Mercapto-olefin Click Reaction And Its Humidification Performance

Air humidity has an important impact on human health and industrial production environment,and air humidity regulation is of great significance.There are many traditional humidifying methods.But"white powder"and droplets in the humidified air,damaging furniture and walls,is produced via the traditional methods.Aiming at these shortcomings,hollow fiber membrane was proposed to humidify the air.Membrane humidification method combine membrane separation technology and air humidification technology simultaneously.In order to exert the humidifying function of hollow fiber membrane humidifier and improve the membrane flux and humidifying efficiency,the super-hydrophobic modification of hollow fiber membrane was proposed in this paper.With polyvinylidene fluoride(PVDF)ultrafiltration membrane as the base membrane,silica was prepared by sol-gel method.POSS-S-PDMS polymer was formed by thiol-ene click reaction between octylenyl POSS and sulfhydryl PDMS.Silicon dioxide and POSS-S-PDMS polymers are coated on the film surface by coating method.To ensure long-term stability,the film surface and the coating,the coating and the coating were all connected by chemical bonds to improve the durability of the coating.Thus,a kind of SiO₂-PDMS-POSS stable super hydrophobic film was prepared.The experiment explored the influence of octavinyl polyhedral oligomeric silsesquioxane(OV-POSS)content,sulfhydryl polydimethylsiloxane(PDMS-SH)content,DMPA content,coating time,silica particle size,etc.The membrane and the composite membrane were characterized.The experimental results showed that when the silica particle size was 252 nm,the POSS content was 0.04 wt%,the PDMS content was 0.1 wt%,DMPA content was 0.015 wt%,and the coating time was 10s,the contact angle of the composite film reached 156°,specific humidification power(SHP)was 0.627 kg/(m²·h),water vapor diffusion rate was 0.014 m/s,and humidification efficiency was increased from 48%to 58.32%.The average contact angle of the composite membrane was reduced by only about 5°after 6 hours of ultrasonic treatment,and it still had strong hydrophobicity.The super-hydrophobic composite membrane was in a stable state within the 180 min humidification experiment.