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Enhancing Dehydration Performance of Isopropanol by Introducing Intermediate Layer into sodium Alginate Nanofibrous Composite Pervaporation Membrane

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Advanced Fiber Materials 2019年第2期1卷 137-151页

作者： Peiyun Li Cheng Cheng Ke shen Tonghui Zhang Xuefen Wang benjamin s.hsiao state Key Lab for Modification of Chemical Fibers and Polymer Materials Donghua UniversityShanghai 201620People’s Republic of China Department of Chemistry Stony Brook UniversityStony BrookNY 11794USA

A novel three-tier composite membrane based on highly porous nanofibrous substrate was demonstrated for efficient iso-propanol dehydration by ***,polyethyleneimine(PEI)modified graphene oxide(GO)sheets were vacuum-assistant assembled onto porous electrospun polyacrylonitrile(PAN)nanofibrous substrate to achieve a smooth,hydrophilic and compact PEI-GO intermediate *** introduction of PEI chains endowed GO interlayer with sufficient interaction for bonding adjacent GO nanosheets to enhance stability in water/isopropanol mixture and also with the ascended inter-lamellar space to improve the water-sorption ability due to the abundant active amino *** from PEI-GO layer,a defect-free sodium alginate(sA)skin layer could be facilely manufactured with elaborately controlled thickness as thin as possible in order to reduce mass transfer resistant and enhance permeability ***,the interlayer would also contribute to enhance interfacial adhesion to promote the structure integrity of three-tier thin-film nanofibrous composite(TFNC)membrane in pervaporation dehydration *** fine-tuning of membrane preparation process,the sA/PEI(75)-GO-60/PAN TFNC membrane exhibited competitive pervaporation performance with the permeate flux of 2009 g/m2 h and the separation factor of 1276 operated at 70°C for dehydration of 90 wt%isopropanol *** unique three-tier composite membrane structure suggested an effective and facile approach to design novel membrane structure for further improvement of pervaporation performance.

关键词： Polyethyleneimine modified graphene oxide Intermediate layer Thin-film nanofibrous composite membrane Pervaporation membrane

MOLECULAR AND sUPRAMOLECULAR ORDERING IN CONFINED ENVIRONMENTs

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Chinese Journal of Polymer science 2000年第4期18卷 287-300页

作者： stephen Z.D.Cheng Bret H.Calhoun Roderic P.Quirk benjamin s.hsiao Maurice Morton Institute and Department of Polymer science The University of Akron Akron Ohio 44325-3909 USAMaurice Morton Institute and Department of Polymer Science The University of Akron Akron Ohio 44325-3909 USAMaurice Morton Institute and Department of Polymer Science The University of Akron Akron Ohio 44325-3909 USADepartment of ChemistryThe State University of New York at Stony Brook Stony Brook New York 11794-3400 USA

Crystal and phase morphologies and structures determined by self-organization of crystalline-amorphous diblockcopolymers, crystallization of the crystallizable blocks, and vitrification of the amorphous blocks are reviewed through asystematic study on a series of poly(ethylene oxide)-b-polystyrene (PEO-b-Ps) diblock copolymers. On the base ofcompetitions among these three processes, molecular and supramolecular ordering in confined environments can beinvestigated. In a concentration-fluctuation-induced disordered (D_(CF)) diblock copolymer, the competition between crystalli-zation of the PEO blocks and vitrification of the Ps blocks is momtored by time-resolved simultaneous small angle X-rayscattering (sAXs) and wide angle X-ray diffraction (WAXD) techniques. In the case of T_cs-rich), the crystallization of thePEO blocks is observed to be confined within the bicontinuous D_(CF) phase due to the rapid vitrification of the Ps-rich *** crystallization rate, crystal melting behavior, and crystallinity results further confirm the competition betweencrystallization and vitrification at different temperatures. In an ordered lamellar PEO-b-Ps diblock copolymer, the crystalli-zation of the PEO blocks is completely confined within the ordered lamellae due to rapid vitrification of the Ps layers asobserved by time-resolved sAXs and WAXD experiments. From the combined two-dimensional sAXs and WAXDmeasurements, the crystal orientation within the confined lamellar geometry is found parallel to the lamellar surface normalwhen it is isothermally crystallized at 35℃. In an ordered cylindrical PEO-b-Ps sample, the crystallization of the PEO blocksis also observed to be confined within the ordered cylinders because of rapid vitrification of the Ps matrix. The crystalorientation within the confined cylinders is found perpendicular to the cylinder axis as it is crystallized at 35℃.

关键词： Poly(ethylene oxide)-b-polystyrene diblock copolymer Molecular ordering, supramolecular ordering, Confined environment

Evolution of Morphology and structure During Crystallization and Melting in syndiotactic Polypropylene

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应用化学 2001年第5期18卷 280-288页

作者： Zhi-Gang WANG benjamin s.hsiao Charles C.HAN state University of New York at stony Brook Department of ChemistryStony BrookNY 11794-3400 Polymers Division and Center for Neutron Research National Institute of Standards and TechnologyGaithersburgMD 20899

structure and morphology development during isothermal crystallization and subsequent melting of syndiotactic polypropylene(sPP) was studied by time-resolved simultaneous small-angle X-ray scattering(sAXs) and wide-angle X-ray diffraction(WAXD) methods with synchrotron radiation and differential scanning calorimetry(DsC). The time and temperature dependent parameters such as long period, L , crystal lamellar thickness, l c, amorphous layer thickness, l a, scattering invariant, Q , crystallinity, X c, lateral crystal sizes, L 200 and L 020 , and unit cell parameters a and b were extracted from sAXs and WAXD profiles. Decreasing long period and crystal thickness indicate that thinner secondary crystal lamellae are formed. The decreases in unit cell parameters a and b during isothermal crystallization process suggest that crystal perfection takes place. The changes in the morphological parameters (the invariant, Q , crystallinity, X c, long period, L , and the crystal thickness, l c) during subsequent melting were found to follow a two-stage melting process, corresponding to the dual endotherm behavior in the DsC scan. We conclude that the dual melting peaks are due to the melting of secondary and primary lamellae(first peak) and the subsequent recrystallization-melting process(second peak). Additional minor endothermic peak located at the lowest temperature was also detected and might be related to melting of secondary, thinner and defective lamellae. WAXD showed that during melting, thermal expansion was greater along the b axis than that along the a axis.

关键词：间规聚丙烯结晶熔化晶体结构 DCs sAXs WAXD

The Influence of Ethyl Branch on Formation of shish-Kebab Crystals in Bimodal Polyethylene under shear at Low Temperature

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Chinese Journal of Polymer science 2021年第8期39卷 1050-1058,I0008页

作者： Zong-Bao Wang Yi-Min Mao Xu-Ke Li Yi-Guo Li Chatchai Jarumaneeroj Boonyakeat Thitisak Piyawan Tiyapiboonchaiya Wonchalerm Rungswangd benjamin s.hsiao Ningbo Key Laboratory of specialty Polymers School of Materials Science and Chemical EngineeringNingbo UniversityNingbo 315211China Department of Materials science and Engineering University of MarylandCollege ParkMaryland 20742USA NIsT Center for Neutron Research National Institute of Standards and TechnologyGaithersburgMaryland 20899USA sCG Chemicals Co. Ltd.Siam Cement Group(SCG).1 Siam Cement Rd.BangsueBangkok 10800Thailand UsA Department of Chemistry Stony Brook UniversityStony BrookNY 11794-3400USA

Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was *** situ small-angle X-ray scattering(sAXs)and wide-angle X-ray diffraction(WAXD)techniques were used to monitor the formation and evolution of shish-kebab structure sheared at low temperature in simple shear mode and low *** the bimodal PE with no branch formed shish-kebab crystals at the shear temperature of 129℃,and the shish length increased with the crystallization time,while bimodal PE with branch has no observable shish under the same *** degree of crystallization for bimodal PE with no branch increased with time up to above 7%,while those with ethyl branch increased continually up to above 23%.Furthermore,bimodal PE's Hermans orientation factor with no branch increased to 0.60,while those with ethyl branch only increased to a value below *** study indicated that the shish-kebab crystal formed at the low temperature of 129℃is due to the stretch of entangled chains under shear for the bimodal PE with no *** partly oriented lamellar crystals were formed for the bimodal PE with ethyl *** the results at the shear temperatures higher,closed to,and lower than the melting point,the modulation of shish crystals formation owing to different mechanisms of the coil-stretch transition and the stretched network by changing shear temperature was achieved in the bimodal PE samples.

关键词： Bimodal polyethylene shish-kebab Ethyl branch shear

New Breakthroughs on Ultra-Filtration Membranes for Water Purification

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New Breakthroughs on Ultra-Filtration Membranes for Water Pu...

A sTUDY OF sTRUCTURE AND PROPERTY CHANGEs OF BIODEGRADABLE POLYGLYCOLIDE AND POLY(GLYCOLIDE-co-LACTIDE)FIBERs DURING PROCEssING AND IN VITRO DEGRADATION

2009年全国高分子学术论文报告会

作者： benjamin s.hsiao Chemistry Department Stony Brook UniversityStony BrookNew York 11794-3400USA

＜正＞Usable water is a resource that shall require considerable *** magnitude and the need for advanced technology related to water treatment,especially for China and the United states,will be briefly *** order to tackle the water treatment problem,large scale production capability has to be taken into *** the present context,advances in electro-spinning and related technologies become *** non-woven structure has unique features,including interconnected pores,very large surface-to-volume ratio,and ease of surface modifications which enable such scaffolds to have many biomedical and industrial *** water purification, we can take advantage of these unique properties to drastically improve flux capacity at low operating pressure but retain their resistance to *** flux means less time to filter the same amount of water,which in turn increases energy and cost *** results on the use of such filters for oil-water separations are presented.

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Chinese Journal of Polymer science 2003年第2期21卷 159-167页

作者： Bruce X.Fu benjamin s.hsiao Gavin Chen Jack Zhou susan Lin Jenny Yuan Ilya Koyfman Dennis D Jamiolkowski Edward Dormier Department of Chemistry State University of New York at Stony Brook Stony BrookNY 11794-3400 USA Ethicon Worldwide A Johnson & Johnson Company P. O. Box 151 Somerville. New Jersey 08876-0151 USA

structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA)fibers were investigated during several industrial processing stages and in vitro degradation by means of wide-angle X-raydiffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the orientation stage, the PGAfibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similarconditions. In the hot-stretching and post-annealing stages, after fibers were braided, PGA samples were found to gain morecrystallinity and higher T_g than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate ofdegradation. DMA results showed that a great deal of internal stress that was built during orientation and hot-stretchingstages was released in the post-annealing stage for a1l PGA and PGA-co-PLA samples. During earlier stages of in vitrodegradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. Theheat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLAsamples, indicating the amorphous portions of the polymers lost orientation after a short period in the buffer solution, mostlikely due to relaxation of the cleaved chains.

关键词： Polyglycolide Poly(glycolide-co-lactide) Bioabsorbable Fiber processing in vitro Degradation

Electro-spinning Technology and its Applications

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Electro-Spinning Technology and its Applications

A Particle-Gel Platform for Controlled Drug Release

2005年全国高分子学术论文报告会

作者： benjamin Chu benjamin s．hsiao Chemistry Department stony Brook University Stony BrookNY 11794-3400 Chemistry Department stony Brook University Stony BrookNY 11794-3400

＜正＞In recent years,there has been an explosive growth of research activities to explore the development of electro-spinning technology and the applications of electro-spun *** 600 scientific papers have been publis...

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A Particle-Gel Platform for Controlled Drug Release

2007年全国高分子学术论文报告会

作者： benjamin Chu benjamin s．hsiao Chemistry Department stony Brook University stony Brook Chemistry Department stony Brook University stony Brook

＜正＞Medicated smart gels,containing lidocaine（as an anesthetic model drug）and Pluronic-based block copolymers（poly（ethylene oxide）-b-poly（propylene oxide）-b-poly（ethylene oxide））in water,can be fine-tuned ...

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甲壳素晶须增强PBC纳米纤维的制备及性能

东华大学学报（自然科学版） 2015年第5期41卷 572-578,614页

作者：邵梅玲东华大学材料科学与工程学院上海201620 东华大学纤维材料改性国家重点实验室上海201620

为了提高脂肪族聚碳酸丁二脂（PBC）纳米纤维的力学性能,首先利用酸解法制得纳米级甲壳素晶须,然后与PBC进行共混复合,通过静电纺丝法制得复合纳米纤维.研究表明,制得的甲壳素晶须长度范围为180-680nm,直径分布范围为15-30nm,平均长径比... 详细信息

为了提高脂肪族聚碳酸丁二脂（PBC）纳米纤维的力学性能,首先利用酸解法制得纳米级甲壳素晶须,然后与PBC进行共混复合,通过静电纺丝法制得复合纳米纤维.研究表明,制得的甲壳素晶须长度范围为180-680nm,直径分布范围为15-30nm,平均长径比为14.85.将晶须分散到甲酸中24h后,对其表面形貌的研究发现,在短时间内甲酸并不会改变晶须形貌,这也为下一步试验提供了依据.对将不同含量的晶须添到PBC中制得的复合纳米纤维的基本性能进行研究,结果表明,当晶须质量分数为5.0%时,制得的纳米纤维表面光滑、直径分布均匀,且随着更多晶须的加入,复合纤维的热稳定性及力学性能得到显著提高.

关键词：脂肪族聚碳酸丁二脂甲壳素晶须静电纺丝纳米纤维