Preparation Of Multi-functional Super-wettability Materials And Their Application In Water Purification

In recent years,with the increasing pollution of oil in industrial production and during offshore oil extraction or transportation,exploring efficiency methods to collect and remove large amounts of organic pollutants from water is attracting global attention.Anisotropically wettable materials have become a hot spot in oil-water separation field because of their obvious opposite absorption properties for oil and water.When using this kind of materials for oil-water separation,the oil-water mixture can be collected and then filtered or in situ absorbing the oil from water by directly connected a pump with the materials,which greatly saves operating costs and has high efficiency.Based on this,in this paper,three kinds of multifunctional super-wettable materials were prepared by a simple solvent immersion method using nanoparticles with specific functions as the core,realizing the integration of oil-water separation,water purification,self-cleaning and photothermal performances.The main research contents and conclusions are as follows:（1）Fabrication and properties of superhydrophilic/underwater superoleophobic APTES-TiO₂ coated fabricSuperhydrophilic/underwater superoleophobicγ-aminopropyltriethoxysilane-TiO₂ coated fabric（APTES-TiO₂@fabric）was prepared by a simple soaking method under solvent-free conditions.The experimental results showed that APTES-TiO₂@fabric had good superhydrophilic underwater superoleophobicity（WAC=0°;UWOAC>152°）,oil-water separation ability（separation efficiencies>99%）and corrosion resistance to acid,alkali and salt.Meanwhile,APTES-TiO2@fabric also exhibited excellent photocatalytic performance,which can degrade methylene blue in water and organic dyes adsorbed on itself.APTES-TiO₂@fabric has good oil-water separation efficiencies and photocatalytic performances,and realizes the integration of oil-water separation,water purification and self-cleaning,which has certain reference significance for the treatment of wastewater in practical industry.（2）Fabrication and properties of photocatalytic superhydrophobic SH-ZnO-PDMS coated fabricSH-ZnO was formed by cross-linking ZnO and dodecyltrimethoxysilane（DTMS）and coated on fabrics.A kind of superhydrophobic SH-ZnO-PDMS@fabric was fabricated by using polydimethylsiloxane（PDMS）as an adhesive,which can enhance the binding force between SH-ZnO and the fabric,and improve the mechanical durability of the fabric.The experimental results showed that SH-ZnO₃-PDMS@fabric exhibited excellent superhydrophobicity（WAC=156.5°,SA=6.5°）and environmental stability（WAC:146.9～156.6°）.In the oil-water separation test,the separation efficiencies of SH-ZnO₃-PDMS@fabric for various oil-water mixtures were greater than 95.5%.Moreover,SH-ZnO₃-PDMS@fabric also exhibited good photocatalytic activity,which can degrade methylene blue in water and oleic acid pollutants on the surface under UV irradiation.This work provides a feasible method for constructing superhydrophobic materials with environmental durability,photocatalysis,and self-cleaning.（3）Preparation and properties of a superhydrophobic photothermal sponge（P-PDA-CS@MF）based on mussel bionics and candle sootPolydopamine（PDA）and candle soot（CS）were sequentially deposited on the melamine formaldehyde sponge（MF）framework,and the superhydrophobic P-CS-PDA@MF sponge was prepared using polydimethylsiloxane（PDMS）as the hydrophobic modifier.The experimental results showed that P-CS-PDA@MF sponge exhibited superhydrophobic performance（WAC=153.56°）,environmental stability（WAC:150.17～152.75°）,oil absorption capacity（oil absorption capacity:33.87～78.90 g/g）and demulsification capacity.More importantly,P-CS-PDA@MF exhibited excellent photothermal performance（ΔT=63°C）,which can accelerate the collection of high-viscosity oil（castor oil）under the assistance of simulated sunligh.In addition,the P-CS-PDA@MF sponge had excellent flame retardancy.The P-CS-PDA@MF sponge has excellent oil absorption and photothermal properties,which provides a feasible method for treating oily wastewater,emulsions,and high viscosity oils.