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A comparative study for petroleum removal capacities of the bacterial consortia entrapped in sodium alginate,sodium alginate/poly(vinyl alcohol),and bushnell haas agar
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作者 Sezen Bilen Ozyurek 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期705-715,共11页
The purpose of this study was to identify and compare the degradation efficiencies of free and entrapped bacterial consortia(Staphylococcus capitis CP053957.1 and Achromobacter marplatensis MT078618.1)to different pol... The purpose of this study was to identify and compare the degradation efficiencies of free and entrapped bacterial consortia(Staphylococcus capitis CP053957.1 and Achromobacter marplatensis MT078618.1)to different polymers such as Sodium Alginate(SA),Sodium Alginate/Poly(Vinyl Alcohol)(SA/PVA),and Bushnell Haas Agar(BHA).In addition to SA and SA/PVA,which are cost-effective,non-toxic and have different functional groups,BHA,which is frequently encountered in laboratory-scale studies but has not been used as an entrapment material until now.Based on these,the polymers with different surface morphologies and chemical compositions were analyzed by SEM and FT-IR.While the petroleum removal efficiency was higher with the entrapped bacterial consortia than with the free one,BHA-entrapped bacterial consortium enhanced the petroleum removal more than SA and SA/PVA.Accordingly,the degradation rate of bacterial consortia entrapped with BHA was 2.039 day^(-1),SA/PVA was 1.560,SA was 0.993,the half-life period of BHA-entrapped bacterial consortia is quite low(t_(1/2)=0.339)compared with SA(t_(1/2)=0.444)and SA/PVA(t_(1/2)=0.697).The effects of the four main factors such as:amount of BHA(0.5,1,1.5,2,2.5,3 g),disc size(4,5,6,7,8 mm),inoculum concentration(1,2.5,5,7.5,10 mL),and incubation period on petroleum removal were also investigated.The maximum petroleum removal(94.5%)was obtained at≥2.5 mL of bacterial consortium entrapped in 2 g BHA with a 7 mm disc size at 168 h and the results were also confirmed by statistical analysis.Although a decrease was observed during the reuse of bacterial consortium entrapped in BHA,the petroleum removal was still above 50%at 10th cycle.Based on GC-MS analysis,the removal capacity of BHA-entrapped consortium was over 90%for short-chain n-alkanes and 80%for medium-chain n-alkanes.Overall,the obtained data are expected to provide a potential guideline in cleaning up the large-scale oil pollution in the future.Since there has been no similar study investigating petroleum removal with the bacterial consortia entrapped with BHA,this novel entrapment material can potentially be used in the treatment of petroleum pollution in advanced remediation studies. 展开更多
关键词 Entrapment of bacterial consortia PETROLEUM RemovalBushnell Haas agar Sodium alginate Sodium alginate/poly(vinyl alcohol)
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Graphene quantum dots doped poly(vinyl alcohol)hybrid membranes for desalination via pervaporation
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作者 Yunyun Wan Lulu Yao Peng Cui 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第11期226-234,共9页
Pervaporation desalination by highly hydrophilic materials such as poly(vinyl alcohol)(PVA)based separation membrane is a burgeoning technology of late years.However,the improvement of membrane flux in pervaporation d... Pervaporation desalination by highly hydrophilic materials such as poly(vinyl alcohol)(PVA)based separation membrane is a burgeoning technology of late years.However,the improvement of membrane flux in pervaporation desalination has been a difficult task.Here,a novel hybrid membrane with doped graphene oxide quantum dots(GOQDs)which is rich in hydrophilic groups and small size into the matrix of PVA was prepared to improve the membrane flux.The membranes structures were described by field emission scanning electron microscopy(FESEM),atomic force microscopy(AFM),Fourier transform infrared(FT-IR),differential scanning calorimetry(DSC),thermogravimetric analysis(TGA)and X-ray diffraction(XRD).And more,Water contact angle,swelling degree,and pervaporation properties were carried out to explore the effect of GOQDs in PVA matrix.In addition,GOQDs content in the hybrid membrane,NaCl concentration,and feed temperature were investigated accordingly.Moreover,the hydrogen bonds between PVA chains were weakened by the interaction between GOQDs and PVA chains.Significantly,the hybrid membrane with optimized doped GOQDs content,200 mg·L^(-1),displays a high membrane flux of 17.09 kg·m^(-2)·h^(-1)and the salt rejection is consistently greater than 99.6%. 展开更多
关键词 PERVAPORATION DESALINATION Graphene oxide quantum dots poly(vinyl alcohol) Membranes
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Improving physical properties of poly(vinyl alcohol)/montmorillonite nanocomposite hydrogels via the Hofmeister effect
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作者 郭蓉蓉 余德帅 +6 位作者 黄一帆 王森 付聪 朱水洪 易佳 王涵淇 林友辉 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第8期6-14,共9页
Hydrogel is a kind of three-dimensional crosslinked polymer material with high moisture content.However,due to the network defects of polymer gels,traditional hydrogels are usually brittle and fragile,which limits the... Hydrogel is a kind of three-dimensional crosslinked polymer material with high moisture content.However,due to the network defects of polymer gels,traditional hydrogels are usually brittle and fragile,which limits their practical applications.Herein,we present a Hofmeister effect-aided facile strategy to prepare high-performance poly(vinyl alcohol)/montmorillonite nanocomposite hydrogels.Layered montmorillonite nanosheets can not only serve as crosslinking agents to enhance the mechanical properties of the hydrogel but also promote the ion conduction.More importantly,based on the Hofmeister effect,the presence of(NH_(4))_(2)SO_(4)can endow nanocomposite hydrogels with excellent mechanical properties by affecting PVA chains'aggregation state and crystallinity.As a result,the as-prepared nanocomposite hydrogels possess unique physical properties,including robust mechanical and electrical properties.The as-prepared hydrogels can be further assembled into a high-performance flexible sensor,which can sensitively detect large-scale and small-scale human activities.The simple design concept of this work is believed to provide a new prospect for developing robust nanocomposite hydrogels and flexible devices in the future. 展开更多
关键词 nanocomposite hydrogels Hofmeister effect network structure poly(vinyl alcohol) MONTMORILLONITE
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Controlled delivery of ibuprofen from poly(vinyl alcohol)-poly(ethylene glycol) interpenetrating polymeric network hydrogels 被引量:4
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作者 Subhraseema Das Usharani Subuddhi 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2019年第2期108-116,共9页
Hydrogels composed of poly(vinyl alcohol)(PVA) and poly(ethylene glycol)(PEG) were synthesized using glutaraldehyde as crosslinker and investigated for controlled delivery of the common anti-inflammatory drug, ibuprof... Hydrogels composed of poly(vinyl alcohol)(PVA) and poly(ethylene glycol)(PEG) were synthesized using glutaraldehyde as crosslinker and investigated for controlled delivery of the common anti-inflammatory drug, ibuprofen(IBF). To regulate the drug delivery, solid inclusion complexes(ICs) of IBF in β–cyclodextrin(β–CD) were prepared and added to the hydrogels. The ICs were prepared by the microwave irradiation method, which is more environmentally benign. The formation of IC was confirmed by various analytical techniques and the synthesized hydrogels were also characterized. Controlled release of drug was achieved from the hydrogels containing the ICs in comparison to the rapid release from hydrogels containing free IBF.The preliminary kinetic analysis emphasized the crucial role of β–CD in the drug release process that influences the polymer relaxation, thereby leading to prolonged release. The cytotoxicity assay validated the hydrogels as non-toxic in nature and hence can be utilized for controlled delivery of IBF. 展开更多
关键词 HYDROGELS poly(vinyl alcohol) poly(ethylene glycol) IBUPROFEN Controlled delivery systems
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A Hybrid Membrane of Poly(vinyl alcohol) and Phosphotungstic Acid for Fuel Cells 被引量:10
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作者 李磊 王宇新 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第5期614-617,共4页
Proton conducting membranes composed of phosphotungstic acid (PWA) and poly(vinyl alcohol) (PVA)were prepared. Conductivity and Fourier transform infrared spectrometer(FTIR) measurements show that most ofthe acid embe... Proton conducting membranes composed of phosphotungstic acid (PWA) and poly(vinyl alcohol) (PVA)were prepared. Conductivity and Fourier transform infrared spectrometer(FTIR) measurements show that most ofthe acid embedded are stable in the PVA matrix when the membrane is immerged in water or methanol solution atroom temperature. Conductivity of the composite membranes scatters around 10-3 S.cm-1 at room temperature.The methanol crossover through the membranes is about an order of magnitude lower than that through Nafion117 membrane. 展开更多
关键词 fuel cell proton conductor composite membrane poly(vinyl alcohol) phosphotungstic acid
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Compatibility and Properties of Biodegradable Blend Films with Gelatin and Poly(vinyl alcohol) 被引量:3
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作者 高喜平 汤克勇 +2 位作者 LIU Jie ZHENG Xuejing ZHANG Yuqing 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第2期351-356,共6页
The blend films with gelatin and poly(vinyl alcohol) (PVA) were prepared by a solution casting method. The compatibility between gelatin and PVA in the blend films was investigated. The transmittance, Fourier-tran... The blend films with gelatin and poly(vinyl alcohol) (PVA) were prepared by a solution casting method. The compatibility between gelatin and PVA in the blend films was investigated. The transmittance, Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), thermogravimetry analysis (TG), and differential scanning calorimetry (DSC) were employed to characterize the resultant blend films. According to optic result, the opacity of the blend film at the ratio of 20/80 (w/w, Gel to PVA) was the lowest, indicating the best compatibility between Gel and PVA at the ratio. The results oflR, XRD, DSC, and TG revealed an intensive interaction and good compatibility between them in the blend film at the ratio. The mechanical properties and solubility showed that PVA content in the blend films obviously affected the elongation at break and solubility. The mechanical properties and water resistance of gelatin film may be improved by the introduetion of PVA. 展开更多
关键词 GELATIN polyvinyl alcohol blend films compatibility PROPERTIES
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Research on the Long Time Swelling Properties of Poly (vinyl alcohol)/Hydroxylapatite Composite Hydrogel 被引量:1
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作者 De-kun Zhang~(1,3), Da-gang Wang~2, Jun-jie Duan~(1,3), Shi-rong Ge~(2,3)1. School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116, P. R. China2. School of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, P. R. China3. Biotribology Center, National Key Laboratory of Tribology, Tsinghua University, Beijing 100083, P. R. China 《Journal of Bionic Engineering》 SCIE EI CSCD 2009年第1期22-28,共7页
Poly(vinyl alcohol)/hydroxylapatite(PVA/HA)composite hydrogel was prepared by repeated freezing and thawing.The water loss properties of the resultant hydrogel were investigated by using optical microscope.Long time i... Poly(vinyl alcohol)/hydroxylapatite(PVA/HA)composite hydrogel was prepared by repeated freezing and thawing.The water loss properties of the resultant hydrogel were investigated by using optical microscope.Long time immersion tests of PVA/HA composite hydrogel were carried out in the diluted calf serum solution to study the change laws of swelling properties with the freezing-thawing cycles and HA content.The micro-morphologies of PVA/HA composite hydrogel after long time immersion were observed by means of the high-accuracy 3D profiler.The results show that the swelling process of PVA/HA composite hydrogel is the converse process of its water loss.Long time swelling ratio curves of PVA/HA composite hydrogel in the calf serum solution are manifested as four stages of quick increase,decrease,slow decrease and stable balance,and its equilibrium swelling ratio decreases with the increase of freezing-thawing cycles and HA content.It is revealed that the network structure of the composite hydrogel immersed for a long period is significantly improved with the increase of HA content. Perfect network structures of PVA/HA composite hydrogel as well as full and equilibrium tissues after swelling equilibrium are obtained when the HA content is 3% and the number of freezing-thawing cycles is 7. 展开更多
关键词 poly (vinyl alcohol) HYDROXYAPATITE composite hydrogel swelling property morphology
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Miscibility of Poly(hydroxybutyrate)/Poly(vinyl alcohol)Melt Blends Plasticized With Glycerol 被引量:2
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作者 Deliane da Silva Cabral Antonio JoséFelix Carvalho 《Journal of Renewable Materials》 SCIE 2019年第4期325-333,共9页
Poly(hydroxybutyrate)/poly(vinyl alcohol)(PHB/PVA)blends plasticized with glycerol were prepared by melt blending of PHB and glycerol plasticized PVA.The PHB/PVA-glycerol compositions were 90:10,75:25 and 50:50 w/w,be... Poly(hydroxybutyrate)/poly(vinyl alcohol)(PHB/PVA)blends plasticized with glycerol were prepared by melt blending of PHB and glycerol plasticized PVA.The PHB/PVA-glycerol compositions were 90:10,75:25 and 50:50 w/w,being the concentration of glycerol in the PVA mixture of 10 wt%.The blends were characterized by infrared spectroscopy,dynamic-mechanical thermal analysis,and scanning electron microscope of the fragile fractured surface.The results showed one single phase blend,indicating miscibility corroborated by the presence of a single glass transition temperature.The blending method proved to be an efficient way to tune PHB properties keeping its biodegradable nature since both PVA and glycerol are fully biodegradable materials. 展开更多
关键词 Blend miscibility melt processing poly(hydroxybutyrate) poly(vinyl alcohol)
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Thermal and structural studies of poly (vinyl alcohol) and hydroxypropyl cellulose blends 被引量:3
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作者 Osiris W. Guirguis Manal T. H. Moselhey 《Natural Science》 2012年第1期57-67,共11页
Polymers and polymeric composites have steadily reflected their importance in our daily life. Blending poly(vinyl alcohol) (PVA) with a potentially useful natural biopolymers such as hydroxypropyl cellulose (HPC) seem... Polymers and polymeric composites have steadily reflected their importance in our daily life. Blending poly(vinyl alcohol) (PVA) with a potentially useful natural biopolymers such as hydroxypropyl cellulose (HPC) seems to be an interesting way of preparing a polymeric blends. In the present work, blends of PVA/HPC of compositions (100/0, 90/10, 75/25, 50/50, 25/75, and 0/100 wt/wt%) were prepared to be used as bioequivalent materials. Thermal analyses [differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)], and X-ray diffraction (XRD) were employed to characterize and reveal the miscibility map and the structural properties of such blend system. The obtained results of the thermal analyses showed variations in the glass transition temperature (Tg) indicating the miscibility of the blend systems. Moreover, the changes in the melting temperature (Tm), shape and area were attributed to the different degrees of crystallinity and the existence of polymer-polymer interactions between PVA and HPC molecules. The X-ray diffraction (XRD) analysis showed broadening and sharpening of peaks at different HPC concentrations with PVA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo-polymers PVA and HPC is possible. The results showed that HPC doped in PVA film can improve the thermal stability of the film under investigation, leading to interesting technological applications. 展开更多
关键词 poly(vinyl alcohol) (PVA) HYDROXYPROPYL Cellulose (HPC) Differential CANNING CALORIMETRY (DSC) THERMOGRAVIMETRIC Analysis (TGA) X-Ray Diffraction (XRD)
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Preparation and Swelling Behavior of Physically Crosslinked Hydrogels Composed of Poly(vinyl alcohol) and Chitosan 被引量:1
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作者 何广华 熊富良 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第6期816-820,共5页
The physically crosslinked poly(vinyl alcohol)/chitosan (CS) composite hydrogels were prepared by cyclic freezing/thawing techniques, and the microstructure and swelling behavior of the hydrogels in the simulated ... The physically crosslinked poly(vinyl alcohol)/chitosan (CS) composite hydrogels were prepared by cyclic freezing/thawing techniques, and the microstructure and swelling behavior of the hydrogels in the simulated gastric (pH 1.0) and intestinal (pH 7.4) media were investigated. The experimental results of infrared spectra (IR), scanning electron microscope (SEM) and differential scanning calorimetry (DSC) demonstrated that poly(vinyl alcohol) and chitosan had good miscibility in the composite hydrogels, and the addition of chitosan perturbed the formation of poly(vinyl alcohol) crystallites. The swelling kinetics results indicated that the composite hydrogels had good pH sensitive properties to the acidic environments, and with the increase of chitosan content in the blend, the maximum swelling degreed and the swelling rate both increased, but it led to more dissolution at pH 1.0. And the composite hydrogels also exhibited good reversible swelling behavior with pH value of the swelling medium altering between 1.0 and 7.4. In addition, the higher freezing/thawing cycle times resulted in the lower swelling rate. Therefore, the swelling behavior of the composite hydrogels could be adjusted by changing the chitosan contents and the freezing/thawing cycle times. 展开更多
关键词 polyvinyl alcohol CHITOSAN HYDROGELS freezing/thawing
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DEVELOPMENT OF A CATALYST FOR SOLUTION OF POLY(VINYL ALCOHOL) IN NON-AQUEOUS MEDIUM 被引量:1
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作者 Prafulla Chetri Narendra Nath Dass Neelotpal Sen Sarma 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第4期501-506,共6页
Chloro ethane dimethyl sulfoxide,C_2H_5Cl·DMSO(ECI·DMSO)was prepared by interaction of acrylic acid with conc.Hydrochloric acid in dimethyl sulfoxide(DMSO)and subsequent decarboxylation with H_2O_2 solution.... Chloro ethane dimethyl sulfoxide,C_2H_5Cl·DMSO(ECI·DMSO)was prepared by interaction of acrylic acid with conc.Hydrochloric acid in dimethyl sulfoxide(DMSO)and subsequent decarboxylation with H_2O_2 solution.The formation of the compound was confirmed by spectral and analytical methods;the molecular weight was determined by cryoscopic method.The solubility of poly(vinyl alcohol)(PVA)in different solvents or mixed solvents at 40℃,50℃and 60℃temperature in the presence of 0.01% of EC1·-DMSO was determined.It tu... 展开更多
关键词 Chloro ethane dimethyl sulfoxide polyvinyl alcohol CATALYST SOLUBILITY
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Effect of Polyvinyl Alcohol with a Thiol End Group on the Properties of Polyacrylic Dispersions and Spray-dried Powder 被引量:1
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作者 林劲冬 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2007年第2期261-265,共5页
The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly (vinyl alcohol) with a thiol end group (PVA-SH) as protective colloid.... The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly (vinyl alcohol) with a thiol end group (PVA-SH) as protective colloid. The dispersions can be transformed into corresponding redispersible powder via a spray dryingcooling process. On-line FT-IR monitoring shows that grafting polymer of PVA-g-PMMA was formed mainly at the stage-1 of the emulsion polymerization. TEM images show, the PVA-SH shell was fragmentary when adding SDS at initial stage and integrated when adding at particle growing or final stage. The particle size turns to be smaller when delayed adding SDS surfactant. Triethanolamine, a co-regulator of PVA-SH, controlled the M to 50 000-70 000 and reduced the PDI to 1.5-1.7. The acrylic dispersions with 0.8wt%-1.5wt% PVA-SH1 can be spray-dried into super dispersible polymer powder (SDPP), which can easily disperse in water and form recon- stituted dispersions with an average particle size smaller than 1 micron. 展开更多
关键词 thiol poly vinyl alcohol polymeric emulsifier emulsion polymerization redispersible powder
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Adsorptive Stripping Voltammetric Study of the Enhancement of Copper(Ⅱ) by Poly(vinyl alcohol), Starch and Polyallylamine 被引量:1
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作者 Ming SONG Hui Min MA Yue Xian HUANG and Shu Quan LIANG (Institute of Chemistry. Academia Sinica, Beijing 100080) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第6期529-532,共4页
Adsorptive enhancements of several water-soluble polymers on copper(Ⅱ) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode. Increases in peak current of cu(Ⅱ) were observed in al... Adsorptive enhancements of several water-soluble polymers on copper(Ⅱ) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode. Increases in peak current of cu(Ⅱ) were observed in alkaline carbonate media. The enhancing power of poly(vinyl alcohol), starch and polyallylamine is 15, 4. 1, and 2.5 times, repectively 展开更多
关键词 II by poly Starch and polyallylamine vinyl alcohol Adsorptive Stripping Voltammetric Study of the Enhancement of Copper poly
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Optimization of the Electrospinning Conditions by Box-Behnken Design to Prepare Poly(Vinyl Alcohol)/Chitosan Crosslinked Nanofibers 被引量:1
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作者 Vinícius R. Viana Willian H. Ferreira +2 位作者 Edwin G. Azero Marcos L. Dias Cristina T. Andrade 《Journal of Materials Science and Chemical Engineering》 2020年第4期13-31,共19页
Electrospun poly(vinyl alcohol)/chitosan nanofibers had their solution and process parameters optimized using a Box-Behnken design and desirability function. Four factors (applied voltage, flow rate, distance tip-to-p... Electrospun poly(vinyl alcohol)/chitosan nanofibers had their solution and process parameters optimized using a Box-Behnken design and desirability function. Four factors (applied voltage, flow rate, distance tip-to-plate and amount of chitosan) were varied to produce electrospun mats with a low fiber diameter. An empirical model was developed for each response using response surface methodology (RSM), which revealed that flow rate had no significant influence on the assessed responses. With desirability function, the optimal conditions to produce the nanofibers were applied voltage of 13.1 kV, 30% chitosan concentration and distance tip-to-plate of 10 cm. The fiber diameter and standard deviation were 196.5 ± 28.3 nm, compared to the predicted values of 185.9 ± 26.8 nm. The desirability function allied with Box-Benhken design proved themselves important tools to predict process parameters for the development of nanofibers. The mats were crosslinked with glutaraldehyde for 24 h and 48 h and presented good water stability and enhanced mechanical properties. 展开更多
关键词 ELECTROSPINNING poly(vinyl alcohol) CHITOSAN Box-Behnken Design
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Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes 被引量:1
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作者 O.Gil-Castell R.Cerveró +2 位作者 R.Teruel-Juanes J.D.Badia A.Ribes-Greus 《Journal of Renewable Materials》 SCIE 2019年第7期655-665,共11页
Crosslinked poly(vinyl alcohol)(PVA)based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells(DEFC).The membranes were functionalised by means of the addition of gr... Crosslinked poly(vinyl alcohol)(PVA)based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells(DEFC).The membranes were functionalised by means of the addition of graphene oxide(GO)and sulfonated graphene oxide(SGO)and crosslinked with sulfosuccinic acid(SSA).The chemical structure was corroborated and suitable thermal properties were found.Although the addition of GO and SGO slightly decreased the proton conductivity of the membranes,a significant reduction of the ethanol solution swelling and crossover was encountered,more relevant for those functionalised with SGO.In general,the composite membranes were stable under simulated service conditions.The addition of GO and SGO particles permitted to buffer the loss and almost retain similar proton conductivity than prior to immersion.These membranes are alternative polyelectrolytes,which overcome current concerns of actual commercial membranes such as the high cost or the crossover phenomenon. 展开更多
关键词 Direct ethanol fuel cell graphene oxide poly(vinyl alcohol) proton exchange membranes proton conductivity
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Synthesis and properties of physically crosslinked poly (vinyl alcohol) hydrogels 被引量:1
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作者 MA Ru-yin XIONG Dang-sheng 《Journal of China University of Mining and Technology》 EI 2008年第2期271-274,共4页
The present study is an investigation of the properties of poly(vinyl alcohol),which would be a better contact lens mate- rial than conventional HEMA in some ways.A transparent PVA hydrogel was prepared from a PVA sol... The present study is an investigation of the properties of poly(vinyl alcohol),which would be a better contact lens mate- rial than conventional HEMA in some ways.A transparent PVA hydrogel was prepared from a PVA solution in a mixed solvent consisting of water and a water-miscible organic solvent,DMSO,by the freezing-thawing method.The water content,visible light transmittance,mechanical and swelling properties of the hydrogels were evaluated as a function of PVA concentration and number of freeze-thaw cycles.The results show that the properties of PVA hydrogels depend on the polymer concentration,the number of freeze-thaw cycles and the addition of the organic solvent. 展开更多
关键词 poly vinyl alcohol HYDROGEL freezing-thawing method swelling property
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Chemical and physical properties of poly (vinyl alcohol) hydrogel films formed by irradiation 被引量:1
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作者 YANG Zhangshan ZHU Nankang +2 位作者 YANG Shuqin QIANG Yizhong WANG Chunlei (Department of Radiation Medicine, Suzhou Medical college, Suzhou 215007) 《Nuclear Science and Techniques》 SCIE CAS CSCD 1999年第1期24-27,共4页
Chemical and physical properties of poly(vinyl alcohol) (PVA) hydrogel films were investigated as a function of production factors. The experimental results show that the gel fraction depends strongly on the radiation... Chemical and physical properties of poly(vinyl alcohol) (PVA) hydrogel films were investigated as a function of production factors. The experimental results show that the gel fraction depends strongly on the radiation dose, the degree of swelling is inversely dependent on the concentration of PVA solution, the tensile strength depends mainly on the PVA blending ratio and the elongation at break is inversely dependent on the radiation dose. 展开更多
关键词 薄膜 聚水凝胶薄膜 辐照形成
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The Impact of Clay Loading on the Relative Intercalation of Poly(Vinyl Alcohol)-Clay Composites 被引量:1
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作者 Moustafa M. Zagho Mahmoud M. Khader 《Journal of Materials Science and Chemical Engineering》 2016年第10期20-31,共13页
Polymer clay nanocomposites (PCN) materials are industrially applied because of their unique properties. However many of their physical and chemical properties have not been determined. The formed structures of polyme... Polymer clay nanocomposites (PCN) materials are industrially applied because of their unique properties. However many of their physical and chemical properties have not been determined. The formed structures of polymer/clay nanocomposite depend on the nature of interactions between polymer chains and clay platelets. According to the possible modes of interactions between polymer matrix and clay sheets, these nanocomposites can be classified into: intercalated, flocculated and exfoliated nanocomposites. In this work, the morphology of the nanocomposite was studied using X-ray diffraction (XRD) and nanoscaning electron microscopy (NSEM). XRD and NSEM measurements confirmed the intercalation between poly(vinyl alcohol) chains and cloisite&reg;20A sheets. Because of the intercalation between the clay platelets and the PVA chains, as the clay concentration increases as the band intensities in FT-IR spectra increase. On the other hand, the XRD did not provide clear shift of any of the clay peaks for PVA/cloisite&reg; 10A nanocomposites and confirm the non-intercalation between PVA matrix and cloisite&reg;10A platelets. The relative intercalation (RI) of PVA/Cloisite&reg;20A nanocomposites declined with increase in the clay loadings. In contrast, for PVA/Cloisite&reg;10A, RI values slightly increased with increasing the clay loading. 展开更多
关键词 poly(vinyl alcohol) Cloisite NANOCOMPOSITES Relative Intercalation FT-IR Spectra
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Microstructure and Mechanical Properties of Poly (Vinyl Chloride) Modified by Silica Fume /Acrylic Core-Shell Impact Modifier Blends 被引量:1
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作者 黄健 马保国 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第5期886-891,共6页
This research explored replacing acrylic core-shell impact modifier (AIM) by silica fume to toughen PVC. 100%, 75%, 50% and 25% of AIM (8 phr) were substituted by silica fume in PVC respectively, and then processe... This research explored replacing acrylic core-shell impact modifier (AIM) by silica fume to toughen PVC. 100%, 75%, 50% and 25% of AIM (8 phr) were substituted by silica fume in PVC respectively, and then processed by dry blending and twin-screw extrusion. Severe silica fume agglomeration was observed by scanning electron microscope (SEM) in the PVC matrix when 8 phr pure silica fume was used and processed by screw speed of 20 rpm. Its tensile strength was thereby reduced by 38% comparing to unmodified PVC. The silica fume was successfully dispersed while the screw speed was slowed down to 10 rpm to give a stronger screw torque and a longer melt residential time in the extruder. The tensile strength was ’recovered’ to a level comparable to unmodified PVC. Impact test were performed on all formulations extruded at 10 rpm screw speed and synergetic toughening effect was found with 50% substitution and it had the impact strength that was comparable to 8 phr pure AIM toughened PVC. 展开更多
关键词 silica fume acrylic impact modifier synergetic effect poly vinyl chloride) tensile strength impact modification twin screw extrusion
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Innovative approach to boosting the chemical stability of AZ31 magnesium alloy using polymer-modified hybrid metal oxides
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作者 Mosab Kaseem Ananda Repycha Safira +3 位作者 Mohammad Aadil Tehseen Zehra Muhammad Ali Khan Arash Fattah-alhosseini 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1068-1081,共14页
Meeting the demands of complex and advanced applications requires the development of high-performance hybrid materials with unique properties.However,the integration of polymeric frameworks with MgO/WO_(3) composite l... Meeting the demands of complex and advanced applications requires the development of high-performance hybrid materials with unique properties.However,the integration of polymeric frameworks with MgO/WO_(3) composite layers faces challenges due to the lack of understanding of the formation mechanism and the challenge of determining the impact of self-assembled architecture on anticorrosive properties.In this study,we aimed to enhance the corrosion resistance of the MgO layer produced by plasma electrolysis(PE)of AZ31 Mg alloy by incorporating WO_(3) with partially phosphorated poly(vinyl alcohol)(PPVA).Two types of porous MgO layers were produced using the PE process with an alkaline-phosphate electrolyte,one with and one without WO_(3) nanoparticles,which were subsequently immersed in an aqueous solution of PPVA.Incorporating PPVA into the WO_(3)-MgO layer resulted in hybrids being deposited in a fragmented manner,creating a“laminar reef-like structure”that sealed most of the structural defects in the layer.The PPVA-sealed WO_(3)-based coating exhibited superior corrosion resistance compared to the other samples.Computational analyses were employed to explore the mechanism underlying the formation of PPVA/WO_(3) hybrids on the MgO layer.These findings suggest that PPVA-WO_(3)-MgO hybrid coatings can potentially improve corrosion resistance in various fields. 展开更多
关键词 Plasma electrolysis poly(vinyl alcohol) Tungsten trioxide SEALING CORROSION DFT.
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