Advanced Materials Interfaces
·
2019
·Vol. 6
·期 17
·1900787
·
IF 4.713
Huayuan Li,Yuan Gao,Pengli Zhu,Xiaomeng Du,Xuecheng Yu,Longquan Ma,Gang Li,Rong Sun,Ching-Ping Wong
Efficient heat dissipation becomes increasingly important for high power density devices. 2D layered material hexagonal (BN) has gained extensive attention due to its superior heat conduction performance. However, phonon scattering within the polymer composites makes it fail to reach the full potential of BN. In this work, a cationic polyelectrolyte namely branched polyethyleneimine (PEI) is utilized to building bridged structure between BN and poly(vinyl alcohol) (PVA) polymer. The PEI on the BN surface can help to restrict the agglomeration of the fillers to achieve more uniform distribution then building more effective thermal conductive channels. When filled with BN@PEI particles at the loading of 50 vol%, the thermal conductivity is increased to 14.22 W m −1 K −1 . The ultrahigh of thermal conductivity is mainly attributed to this linear polyelectrolyte bridged molecular which can be acted as a phonon transfer pathway between BN and PVA matrix and lead to the remarkably decrease of interface thermal resistance. In addition, mechanical performance of the BN@PEI/PVA composites is also attributed to the enhanced interfacial affinity between filler and polymer matrix. This work provides an effective universal strategy to design polymer composites to improve the efficiency of heat dissipation in next-generation high power products.
研究领域:
材料科学
·
热管理工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 58
·36313-36318
·
IF 3.108
Wen Zhu,Haizhi Wang,Guoshan Jing,Qianqian Liu,Chunxi Li,Hong Meng
Bipolar membrane processes have evolved as one of the most promising technologies in the field of acid and base production as well as many interesting separation applications. Herein, we report a rapid spray-crosslinked assembly for fabricating a high-performance polyelectrolyte bipolar membrane. Polyvinyl alcohol (PVA), glutaricdialdehyde (GA) and polyethyleneimine (PEI) are alternatively and successively sprayed onto a supporting cation-exchange membrane. GA crosslinked PVA and PEI are responsible for the interlayer and anion-exchange layer, respectively. Under optimal conditions, at a current density of 100 mA cm−2, the cell voltage of the BPM was as low as 1.79 V. Moreover, it has been demonstrated that the spray crosslinked membrane has good stability in acid and alkali harsh conditions. In contrast to the traditional casting method, spray assembly combined with chemical cross-linking can tune the membrane thickness at the nanoscale and microscale levels, as well as increase its charge density and ion-exchange capacity. This facile approach might open a new way to efficiently and flexibly produce various bipolar membranes with different polyelectrolytes.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 33
·e55829
·
IF 2.7
Tianyu Liu,Dandan Chen,Feng Gao,Yuchen Song,Zhuo Zheng,Jian Kang,Ruizhang Xu,Xiaojun Zhang,Yue Zhang,Zhihui Xie,Ming Xiang
Polyethylene-supported nanofiltration (NF) membranes have been reported for several cases in recent years. However, few have disclosed a NF membrane which achieves a high salt/water separation efficiency. Here, a novel polyamide NF membrane was prepared by conducting interfacial polymerization on poly(vinyl alcohol)-decorated polyethylene separator. The polyethylene-supported NF membranes were systematically investigated with respect to chemical structures, microscopic morphology, surface properties, as well as desalination performance. In particular, a distinctive morphology transformation occurred on the polyamide layers through regulating poly(vinyl alcohol) loading amounts. Performance testings demonstrated the optimal membrane reaches a water permeance over 17.4 L·m −2 ·h −1 ·bar −1 and Na 2 SO 4 rejection above 98.7%, as well as favorable performance stability. This work may provide some consideration for fabricating NF membranes with new support layers and good desalination performance.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2016
·
IF 3.997
Leishan Shao,Jingjing Li,Yu Guang,Yuliang Zhang,Heng Zhang,Xinyuan Che,Yinghan Wang
This study presents a straightforward route to fabricate robust poly(vinyl alcohol) (PVA)/polyethyleneimine-functionalized graphene (PVA/rGO/PEI) composite films by combining of surface modification, reduction and composite preparation. Branched polyethylenimine (PEI), as an effective reducing agent and surface modifier of graphene oxide (GO), has been presented to yield PEI-functionalized graphene in PVA aqueous solution. The obtained PVA/PEI-functionalized graphene composites exhibited significant improvements in strength and toughness. At a PEI: GO ratio of 0.5:1, the tensile strength and Young's modulus of PVA/rGO/0.5PEI composite increased by 55.8% and 43.1%, respectively from pure PVA, and the elongation at break also increased from 77.1% (for PVA/GO composite) to 147.3%. With regard to simultaneous strengthening and toughening effects, the strong interfacial interactions produced by the mechanism of hydrogen bonding between amine of PEI and hydroxyl groups of PVA play a key role, which not only increase load transfer efficiency but accelerate crystallization of PVA.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2010
·Vol. 35
·期 2
·360-368
·
IF 3.006
Xu Fang,Shili Xiao,Mingwu Shen,Rui Guo,Shanyuan Wang,Xiangyang Shi
We report the fabrication of water-stable electrospun polyethyleneimine (PEI)/polyvinyl alcohol (PVA) nanofibers that have super dye sorption capability. Electrospinning parameters including flow rate, applied voltage, and polymer concentration were optimized to obtain smooth and uniform PEI/PVA nanofibers. The nanofibers with a mean diameter of 490 ± 83 nm can be rendered water insoluble via crosslinking using glutaraldehyde vapor. The formed nanofibers with a smooth and uniform morphology before and after crosslinking were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and mechanical property testing. The sorption capability of the PEI/PVA nanofibers was confirmed by UV-vis spectrometry. We show that the water-stable nanofibrous mats can effectively absorb methyl blue, which is a typical dye used in the printing and dyeing industry. The dye sorption kinetics and isotherm follow the pseudo-second-order model and the Langmuir model, respectively. The developed polymer nanofiber system has a great potential in decolorizing dyeing wastewater for environmental remediation applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2016
·Vol. 218
·期 4
·1600449
·
IF 2.495
Yongjie Zhang,Qian Li,Wenbo Wang,Anru Guo,Jie Li,Huayi Li
Surface modification of carbon nanotubes (CNTs) with long polymer chains has attracted great attention since it promises high performance nanomaterials. However, due to the chemical inertness of both polyethylene (PE) and CNT, it still remains a challenge to covalently conjugate CNT with PE in a facile manner. In this report, trimethoxysilane terminated PE (TMS-PE) and trimethoxysilane modified multiwall carbon nanotube (TMS-MWNT) is prepared through radical mediated thiol-ene addition reaction between (3-mercaptopropyl)trimethoxysilane and vinyl terminated PE or pristine carbon nanotube, respectively. Subsequently, organotin-catalyzed hydrolytic co-condensation of TMS-PE and TMS-MWNT lead to PE covalently grafted mutliwall CNT (PE-Si-MWNT) with high graft ratio (17.5 wt%). Such reactions are robust and efficient and the reaction conditions are mild. In addition, the authors provide the very first evidence that end-grafted PE chains in PE-Si-MWNT, which are clearly observed in TEM images, can render high compatibility and good interfacial interactions between CNT and low density PE (LDPE) matrix and thus promote homogeneous dispersion of CNT into LDPE matrix as shown by scanning electron microscopy (SEM) characterization of brittle fracture surfaces of LDPE/PE-Si-MWNT nanocomposites.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Junhui Wu,Zhi Wang,Yao Wang,Wentao Yan,Jixiao Wang,Shichang Wang
It is known that some commercially antifouling reverse osmosis (RO) membranes are coated with polyvinyl alcohol (PVA) layers. In this work, a new antifouling RO membrane was prepared by surface grafting of a commercial RO membrane (RE4021-TE from Woongjin, without a PVA layer) with the positively charged and hydrophilic polyvinylamine (PVAm) which was synthesized in lab. To determine the similarities and differences between the PVAm-grafted and PVA-coated membranes, one lab-prepared PVA-coated membrane (also coating on the TE membrane) and two typical commercially antifouling RO membranes with PVA coating layers (BW30FR from Filmtec and LFC3 from Hydranautics) were used for comparisons. Successful synthesis of PVAm was confirmed by the results of the ATR-FTIR and 1 H-NMR analyses. ATR-FTIR, XPS and zeta potential measurements of the membranes together indicated that the PVAm was successfully grafted onto the TE membrane surface. The membrane surface became more hydrophilic and smoother after the PVAm grafting. More importantly, for the TE membrane, the membrane surface charge climbed from negative to positive values after the grafting of PVAm with increasing concentrations, while the surface was still negatively charged after the PVA coating though the charge density was reduced. Besides, the PVAm grafting had smaller influence on the membrane permselectivity than the PVA coating: after the PVAm grafting (with a concentration of 0.20 w/v%) the salt rejection was slightly increased and the water flux decreased by 12.4%, but after the PVA coating the salt rejection was slightly declined and the water flux decreased by 35.4%. Fouling behaviors of the membrane grafted with 0.20 w/v% PVAm and the other three membranes with PVA coating layers were investigated and compared using two proteins (bovine serum albumin (BSA) and lysozyme), one polysaccharide (sodium alginate, SA), one surfactant (dodecyltrimethylammonium bromide, DTAB) and one colloid (colloidal ferric hydroxide, Fe(OH) 3 ) as model foulants. The results showed that the PVAm-grafted membrane exhibited better antifouling property than the two commercially antifouling RO membranes with PVA coating layers. In addition, fouling behavior of the lab-prepared PVA-coated membrane indicated that lower initial water flux resulted in less initial flux decline in the fouling process. This work provides a new potential strategy for improvement of antifouling property of commercial RO membranes besides the traditional PVA coating process .
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2023
·
IF 2.8
Hao Wang,Liwei Zheng,Bo Yuan,Shiwei Guo,Chungang Yuan
Polyethyleneimine (PEI) based positive charge nanofiltration (NF) membranes have unique advantages in the removal of heavy metals. The regulation mechanism of the interlayer when PEI was used as monomer was still not clear. In this study, a PVA-based interlayer was constructed on the origin PES sublayer to tailor the interfacial polymerization in PEI systems. It was proved that the PVA interlayer can further elevate the PWP and rejections of heavy metals. Moreover, the absorption effect of interlayers could contribute to better removal of heavy metals. More negative charges of interlayer could result in a more enough and uniform absorption of PEI monomer as well as a slower diffusion rate of PEI monomer during the interfacial polymerization reaction, thus forming a loose top surface but dense sub-separating layer. This study provides new insight into the effect of interlayer on the performance of PEI-based nanofiltration membrane.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2024
·
IF 3.6
Min Xiao,Zifeng Wang,Yanru An,Yingqi Dai,Xinghao Wang,Zhigang Zhu
Microneedles offer minimally invasive, user-friendly, and subcutaneously accessible transdermal drug delivery and have been widely investigated as an effective transdermal delivery system. Ibuprofen is a common anti-inflammatory drug to treat chronic inflammation. It is crucial to develop microneedle patches capable of efficiently delivering ibuprofen through the skin for the effective treatment of arthritis patients requiring repeated medication. In this study, the mechanical properties of a new type of polymer microneedle were studied by finite element analysis, and the experimental results showed that the microneedle could effectively deliver drugs through the skin. In addition, a high ibuprofen-loaded microneedle patch was successfully prepared by micromolding and subjected to evaluation of its infrared spectrum morphology and dissolve degree. The morphology of microneedles was characterized by scanning electron microscopy, and the mechanical properties were assessed using a built linear stretching system. In the in-vitro diffusion cell drug release test, the microneedle released 85.2 ± 1.52% (210 ± 3.7 μg) ibuprofen in the modified Franz diffusion within 4 h, exhibiting a higher drug release compared to other drug delivery methods. This study provides a portable, safe and efficient treatment approach for arthritis patients requiring daily repeated medication.
研究领域:
药剂学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2013
·Vol. 46
·期 34
·345303
·
IF 2.528
Pan Wang,Han Zhu,Shiyong Bao,MingLiang Du,Ming Zhang
Two strategies are demonstrated to fabricate AgNPs/PVA and AgNPs/(PVA/PEI) nanofibre hybrids. In the first approach, we synthesized AgNPs in poly(vinylalcohol) (PVA) solution and then electrospun the AgNPs/PVA solution into the AgNPs/PVA nanofibres. In the other one, the polyethylenimine (PEI) was introduced to improve the water-stability of PVA and then the AgNPs were immobilized on electrospun PVA/PEI nanofibres to fabricate the AgNPs/(PVA/PEI) nanofibres. Field-emission scanning electron microscopy, transmission electron microscopy, ultraviolet–visible spectroscopy and x-ray photoelectron spectroscopy (XPS) were utilized to investigate the morphology and the growth mechanism of the hybrids. The investigations demonstrate that both of the obtained AgNPs/PVA hybrids and AgNPs/(PVA/PEI) hybrids exhibit good water-stability and good antibacterial activity against E. coli and S. aureus.
研究领域:
材料科学
·
微生物学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2016
·
IF 3.902
Wenwen Wang,Hao Zhang,Zhifeng Zhang,Mengying Luo,Yuedan Wang,Qiongzhen Liu,Yuanli Chen,Mufang Li,Dong Wang
In this study, poly(vinyl alcohol- co -ethylene) (PVA- co -PE) nanofibrous membrane was activated by sodium hydroxide and cyanuric chloride, and then the activated membranes were functionalized by 1,3-propanediamine, hexamethylenediamine and diethylenetriamine to be affinity membranes for bilirubin removal, respectively. The chemical structures and morphologies of membranes were investigated by SEM, FTIR and XPS. And the adsorption ability of different amine-functionalized nanofibrous membranes for bilirubin was characterized. Furthermore, the effects of temperature, initial concentration of bilirubin, NaCl concentration and BSA concentration on the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane were studied. Results indicated that the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane could reach 85 mg/g membrane when the initial bilirubin concentration was 200 mg/L while the adsorption capacity could be increased to 110 mg/g membrane if the initial bilirubin concentration was more than 400 mg/L. The dynamic adsorption of diethylenetriamine-functionalized nanofibrous membrane showed that the ligands of amine groups on the membrane surface could be used as far as possible by recirculating the plasma with certain flow rates. Therefore, the diethylenetriamine-functionalized PVA- co -PE nanofibrous membrane possessed high adsorption capacity for bilirubin and it can be candidate as affinity membrane for bilirubin removal.
研究领域:
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS & DESIGN
·
2018
·
IF 4.525
Yafei Xiao,Wenjuan Huang,Kaijun Xu,Mingxin Li,Minmin Fan,Ke Wang
A series of anion exchange membranes (AEMs) consisting of polyvinyl alcohol/branched polyethyleneimine (PVA/BPEI) were simply prepared by casting method using glutaraldehyde (GA) as crosslinking agent, then quaternized with benzyl chloride and alkalized in KOH solution. Subsequently, the comparative analysis was performed to select the optimal ratio of PVA to BPEI and crosslinking degree of AEMs. The structure and properties of AEMs were verified by FT-IR, XRD, TGA, mechanical analysis, water uptake test, swelling ratio test, ion exchange capacity (IEC) test, ionic conductivity measurement, and alkaline/oxidative stability test. The results showed that the maximum value of ionic conductivity was 86.0 mS/cm at 80 °C with IEC value of 2.35 meq/g. Moreover, the AEM had excellent chemical stability, as the ionic conductivity decreased by <15% in 1 M KOH at 80 °C for 7 days. These results indicated that polyethyleneimine is a promising raw material for the preparation of alkaline anion-exchange membranes used in fuel cell.
研究领域:
材料科学
·
化学工程
·
燃料电池技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）