Fabrication And Characterization Of Superhydrophobic And Superoleophilic MoS₂ Sponge

In recent years,with the rapid growth of the global energy demand,the pace of exploration,exploitation and supply of crude oil has accelerated noticeably.Offshore oil spills have occurred frequently,causing serious damage to fragile marine ecology.In addition,the willful spill of industrial oily wastewater also has brought great challenge to the fresh water resources for human survival.Therefore,how to separate the oil/water mixture in a efficient and eco-friendly manner and protect the water environment,has already become a worldwide problem.In this dissertation,superhydrophobic MoS₂ sponge for oil-water separation was prepared based on facile and effective method,and its related properties were investigated in detail.The main works are listed as follows:?1?The hollow spherical-flower like MoS₂ with superhydrophobicity was prepared by CTAB-assisted hydrothermal process.With the increase of CTAB content,the morphology of as-prepared MoS₂ was gradually changed from cluttered-sheet-stack structure to regular hollow-spherical-flower structure,and its morphology got coarse and reunited with excessive CTAB added,while the corresponding contact angle increased firstly and then decreased.The superhydrophobic spherical-flower like MoS₂ with contact angle of 156° can be obtained with 0.2g CTAB.?2?By coating as-prepared superhydrophobic MoS₂ onto the hydrophilic melamine sponge,superhydrophobic and superoleophilic MoS₂ sponge?SMS?was prepared through the repeated dipping-drying process.The SMS with water contact angle of 154° was obtained when MoS₂ was soaked for 6 times,while the maximum contact angle can be up to 155°±2° as MoS₂ loading rate reached13.54%,exhibiting a excellent self-cleaning performance.The SMS can maintain stable hydrophobicity for a long time under the harsh conditions such as strong acid,alkali and high/low temperature.In terms of oil-water separation performance,the SMS can absorb its own weight of 66.25¹57.93 times for different organic solvents,which is closely related to the density of organic solvents,and also displays a stable repeatability of oil absorption.In the application,the SMS could carry on a simple oil-water separation process through absorption or filtration.Moreover,a continuous efficient oil-water separation in situ apparatus can be achieved via connecting theSMS with a pump and some pipes.?3?The superhydrophobic MoS₂/PDMS sponge?SMPS?was prepared by a PDMS curing method,which can effectively improve the durability of SMS.The SMPS with water contact angle of 148±2° can hold its hydrophobicity in acid/alkali and high/low temperature conditions.Moreover,the contact angles of SMPS are 146.7° and 140.2°after the cycle experiments of 20 times extrusion or friction respectively,showing good mechanical durability.Even the oil absorption capacity of the SMPS is only29.07⁶7.26 times its own weight for various organic solutions,but it shows more durable hydrophobicity and circulating oil absorption capacity.Based on a simple pump-oil separation device,the presented SMPS in this work could provide a feasible solution for disposing large-scale oils sewage.