Pervaporation performance and characterization of hydrophilic ZSM-5 zeolite membranes for high inorganic acid and inorganic salts

The hydrophilic ZSM-5 zeolite membranes are applied to separate the inorganic acid solutions and inorganic acid/inorganic salt mixtures by pervaporation,and the membrane presents good stability,dehydration,and desalination performance.Influences of inorganic acid type(H_(2)SO_(4),H_(3)PO_(4),HNO_(3),and HCl),H_(2)SO_(4)concentration(1e6 mol·L^(-1)),test temperature(60-90℃)and inorganic acid/inorganic salt type(2 mol·L^(-1)H_(2)SO_(4)and sulfate,2 mol·L^(-1)H3PO4 and phosphate)on the pervaporation performance are investigated in this work.Either for concentrating 3%(mass)H_(2)SO_(4)solution or consecutive dehydrating 20%(mass)H_(2)SO_(4)solution,the hydrophilic ZSM-5 zeolite membrane has a good dehydration performance and stability.Even though the H_(2)SO_(4)concentration and test temperature are increased to 6 M and 90℃,only H_(2)O molecules could pass through the membrane and pH value of the permeation is kept neutral.Besides,the membrane has good dehydration and desalination performance for H_(2)SO_(4)/sulfates and H_(3)PO_(4)/phosphate mixtures,and the rejection of natrium salt,molysite,and magnesium is almost 100%.

Hydrophilic polymeric membrane supported on silver nanoparticle surface decorated polyester textile:Toward enhancement of water flux and dye removal

A novel mixed matrix nanofiltration membrane was constructed by coating a casting solution containing polyvinylidene fluoride(PVDF),polyethylene glycol(PEG)as hydrophilic agent,zeolitic like framework-67(ZIF-67),ethylenediamine as cross-linking agent on Ag-nanoparticle-decorated polyester textile(PT)support(PT/AgNPs/PVDF-PEG/ZIF-67).PT/Ag-NPs/PVDF-PEG/ZIF-67 morphology,crystalline structure,surface chemical composition and hydrophilicity of PT/Ag-NPs/PVDF-PEG/ZIF-67 were fully characterized by field emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and water contact angle technique,respectively.PT/Ag-NPs/PVDF-PEG/ZIF-67 was applied in cross module set-up for removal of contaminated water containing rose bengal(RB)dye.The effect of operational parameters such as dye concentration,solution pH and flow rate on performance of PT/Ag-NPs/PVDF-PEG/ZIF-67 were investigated and optimized by central composite design(CCD).Casting solution containing 0.5 wt.%ZIF-67 as optimum value showed the good wettability,high pure water flux(PWF;35.8 L·m-2·h-1),flux recovery ratio(FRR;90%),dye removal efficiency(96.41%).The selectivity factor of 12.72 and 14.42 was found to be for RB in the presence of amido black and methylene blue as interferent dyes,respectively,which showed a good selective recognition ability for RB dye.

Severe prelenticular membrane formation on the surface of a hydrophilic acrylic intraocular lens after cataract surgery in an eye with an Ahmed valve implant

【正】Dear Sir,Iam Yong-Sun Ahn,from the Department of Ophthalmology of St.Vincent Hospital of Suwon,Kyungki-do,South Korea.Cataracts are a common problem in eyes with a glaucoma drainage device(GDD),because tube shunt surgery increases the incidence and progression of cataracts[1].An Ahmed valve,the most commonly inserted GDD,is composed of a silicone tube connected to a flat plate sewn to the sclera,and aqueous humor flows from the

Synergistic action of non-solvent induced phase separation in preparation of poly(vinyl butyral) hollow fiber membrane via thermally induced phase separation

A systematic study of air gap distance effects on the structure and properties of poly(vinyl butyral)hollow fiber membrane via thermally induced phase separation(TIPS)has been carried out.The results show that the hollow fiber membrane prepared at air gap zero has no skin layer; the pore size near the outer surface is larger than that near the inner surface; and the special pore channel-like structure near the outer surface is formed,which is quite different with the typical sponge-like structure caused by TIPS and the finger-like structure caused by non-solvent induced phase separation(NIPS),because of the synergistic action of non-solvent induced phase separation at air gap zero.The pore size gradually decreases from outer surface layer to the intermediate layer,but increases gradually from intermediate layer to the inner surface layer.With the increase of air gap distance,the pore size near the outer surface gets smaller and a dense skin layer is formed,and the pore size gradually increases from the outer surface layer to the inner surface layer.Water permeability of the hollow fiber membrane decreases with air gap distance,the water permeability decreases sharply from 45.50×10-7 to 4.52×10-7 m3/(m2·s·kPa)as air gap increases from 0 to 10 mm at take-up speed of 0.236 m/s,further decreases from 4.52×10-7 to 1.00×10-8 m3/(m2·s·kPa)as the air gap increases from 10 to 40 mm.Both the breaking strength and the elongation increase with the increase of air gap distance.The breaking strength increases from 2.25 MPa to 4.19 MPa and the elongation increases from 33.9% to 132.6% as air gap increases from 0 mm to 40 mm at take-up speed 0.236 m/s.

Hydrophilic/underwater superoleophobic graphene oxide membrane intercalated by TiO2 nanotubes for oil/water separation

Membrane technology for oil/water separation has received increasing attention in recent years. In this study, the hydrophilic/underwater superoleophobic membrane with enhanced water permeability and antifouling ability were fabricated by synergistically assembling graphene oxide （GO） nanosheets and titanium dioxide （TiO2） nanotubes for oil/water separation. GO/TiO2 membrane exhibits hydrophilic and underwater superoleophobic properties with water contact angle of 62° and under water oil contact angle of 162.8°. GO/TiO2 membrane shows greater water permeability with the water flux up to 531 L/ （m^2·h·bar）, which was more than 5 times that of the pristine GO membrane. Moreover, GO/TiO2 membrane had excellent oil/water separation efficiency and anti-oil-fouling capability, as oil residual in filtrate after separation was below 5 mg/L and flux recovery ratios were over 80%.The results indicate that the intercalation of TiO2 nanotubes into adjacent GO nanosheets enlarged the channel structure and modified surface topography of the obtained GO/TiO2 membranes, which improved the hydrophilicity, permeability and anti-oil-fouling ability of the membranes, enlightening the great prospects of GO/TiO2 membrane in oil-water treatment.

G-CNTs/PVDF mixed matrix membranes with improved antifouling properties and filtration performance

Although carbon nanomaterials have been widely used as effective nanofillers for fabrication of mixed matrix membranes(MMMs)with outstanding performances,the reproducibility of the fabricated MMMs is still hindered by the non-homogenous dispersion of these carbon nanofillers in membrane substrate.Herein,we report an effective way to improve the compatibility of carbon-based nanomaterials with membrane matrixes.By chemically conjugating the oxidized CNTs(o-CNTs)and GO using hexanediamine as cross-linker,a novel carbon nanohybrid material(G-CNTs)was synthesized,which inherited both the advanced properties of multi-walled carbon nanotubes(CNTs)and graphene oxide(G0).The G-CNTs incorporated polyvinylidene fluoride(PVDF)MMMs(GCNTs/PVDF)were fabricated via a non-solvent induced phase separation(NIPS)method.The filtration and antifouling performances of G-CNTs/PVDF were evaluated using distillate water and a1g/L bovine serum albumin(BSA)aqueous solution under 0.10 MPa.Compared to the MMMs prepared with o-CNTs,GO,the physical mixture of o-CNTs and GO and pure PVDF membrane,the G-CNTs/PVDF membrane exhibited the highest water flux up to 220 L/m%and a flux recovery ratio as high as 90%,as well as the best BSA rejection rate.The excellent performances should be attributed to the increased membrane pore size,porosity and hydrophilicity of the resulted membrane.The successful synthesis of the novel nanohybrid G-CNTs provides a new type of nanofillers for MMMs fabrication.

Preparation and characterization of antibacterial microporous membranes fabricated by poly(AMS-co-DMAEMA)grafted polypropylene via melt-stretching method

Polypropylene microporous membranes are typical hydrophobic separation membranes, but the high hydrophobicity and lack of functionality easily cause bacterial adhesion, thus inducing membrane pollution. Poly（AMS-co-DMAEMA） （PAD） was designed and synthesized by copolymerization of a-methyl styrene （AMS） and functional monomer 2-（dimethylamino）ethyl methacrylate （DMAEMA）, and then grafted onto PP chains by melt blending. Microporous membranes of blended PP containing different contents of PAD are made by casting and stretching, and the polycation microporous membrane is then obtained via quaternization. The permeability and porosity of the microporous membrane achieve the best when the grafting efficiency reaches 42.16%, and the hydrophilicity of the microporous membrane is improved. The results show that the modified membranes fabricated in this method have good antibacterial properties.

Improved blending strategy for membrane modification virtue of surface segregation using surface-tailored amphiphilic nanoparticles

Membrane modification is one of the most feasible and effective solutions to membrane fouling proble.m which tenaciousl.y hampers .the furher au .gmentation of me .rnbrane sep.aration technology.Blending modification with nanoparticles （NPs）, owing to the convenience of being incorporated in established membrane.p.rodu. ction lines, possesses an advantag, eous viability in practical applications.However, the existing blending strategy suffers from a low utilization efficiency due to NP encasement by membrane matrix. The current study proposed an improved blending modification approach with amphiphilic NPs （aNPs）, which were prepared through silanization using 3-（Trimethoxysilyl）propyl methacrylate （TMSPMA） as coupling agents and ZnO or SiO2 as pristine NPs （pNPs）, respectively.The Fourier transform infrared and X-ray photoelectron spectroscopy analyses revealed thepresence of appropriate organic components in both the ZnO and SiO2 aNPs, which verified the success of the silanization process. As compared with the pristine and conventional pNP-blended membranes, both the ZnO aNP-blended and SiO2 aNP-blended membranes with proper silanization （100% and 200% w/w） achieved a significantly increased blending efficiency with more NPs scattenng on the internal and external membrane surfaces under scanning electron microscope observation. This improvement contributed to the increase of membrane hydrophilicity. Nevertheless, an extra dosage of the TMSPMA led to an encasement of NPs, thereby adversely affecting the properties of the resultant membranes. On the basis of all the tests, 100% （w/w） was selected as the optimum TMSPMA dosage for blending modification for both the ZnO and SiO2 types.