Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated ...Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated through thermal difference.This technology offers strong desalination capabilities and efficiently harnesses low-grade thermal energy sources,including geothermal and waste heat,making it a cost-effective solution for freshwater scarcity.Nevertheless,hydrophobic membranes are prone to contamination by surfactants,inorganic salts,and other substances in feed solutions.To address this,low-surface-energy composite nano-inorganic materials composed of carbon nanotubes and silica were modified and synthesized via organosilicon chemistry.A superhydrophobic surface exhibiting a water contact angle of157.96°was successfully fabricated using above nano-materials on poly(vinylidene fluoride)(PVDF)membrane surface with micro-nano structures via a one-step spray-coating method.Compared to unmodified PVDF membra ne,the superhydrophobic membrane demonstrated superior resistance to common scaling agents such as CaCl_(2),Mg(OH)_(2),CaCO_(3),and CaSO_(4),while maintaining stable permeate flux(13.4 kg·m^(-2)·h^(-1))during MD tests.Additionally,the modified membra ne exhibited enhanced wetting resistance when treating feed solutions containing sodium dodecyl sulfate(SDS),significantly extending the operational lifespan of the membrane.Due to its outstanding performance,this superhydrophobic membrane is expected to promote the practical application of MD technology in the treatment of complex wa stewater and efficient seawater desalination.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22308085)Science and Technology Plan Project of Shijiazhuang(Nos.241130547A and241791337A)Natural Science Foundation of Hebei Province(No.B2020208083)。
文摘Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated through thermal difference.This technology offers strong desalination capabilities and efficiently harnesses low-grade thermal energy sources,including geothermal and waste heat,making it a cost-effective solution for freshwater scarcity.Nevertheless,hydrophobic membranes are prone to contamination by surfactants,inorganic salts,and other substances in feed solutions.To address this,low-surface-energy composite nano-inorganic materials composed of carbon nanotubes and silica were modified and synthesized via organosilicon chemistry.A superhydrophobic surface exhibiting a water contact angle of157.96°was successfully fabricated using above nano-materials on poly(vinylidene fluoride)(PVDF)membrane surface with micro-nano structures via a one-step spray-coating method.Compared to unmodified PVDF membra ne,the superhydrophobic membrane demonstrated superior resistance to common scaling agents such as CaCl_(2),Mg(OH)_(2),CaCO_(3),and CaSO_(4),while maintaining stable permeate flux(13.4 kg·m^(-2)·h^(-1))during MD tests.Additionally,the modified membra ne exhibited enhanced wetting resistance when treating feed solutions containing sodium dodecyl sulfate(SDS),significantly extending the operational lifespan of the membrane.Due to its outstanding performance,this superhydrophobic membrane is expected to promote the practical application of MD technology in the treatment of complex wa stewater and efficient seawater desalination.
