JOURNAL OF POLYMER RESEARCH
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2024
·Vol. 32
·期 1
·1-10
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IF 2.6
Gu Kaifeng,Fang Chuanjie,Wang Jianyu,Zhu Liping
Nanofiltration (NF) is one of the most promising separation technologies of this century. It plays a major role in the chemical, medical, food, and other fields. The separation and permeation performance of NF membranes is closely related to microstructure. In this study, aqueous phase amine monomers are pre-crosslinked during the preparation of NF membranes. Trimesic acid (TMA) is used as a cross-linking agent with polyethyleneimine (PEI), whereby the resulting aqueous-phase monomer is interfacially polymerized with the organic-phase monomer to form a separation layer with internal lithium-ion permeation channels. The physicochemical structure of nanofiltration membranes is analyzed in detail. The pre-crosslinking process is optimized and the NF membrane performance can achieve 97% rejection of MgCl 2 , 15% rejection of LiCl, and 34 L m −2 h −1 permeate flux. The resulting NF membranes also show stable desalination performance in tests with mixed salt solutions. This study provides a new nanofiltration membrane structure and performance optimization scheme, which is favorable for magnesium-lithium separation systems.
研究领域:
化学工程
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材料科学
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环境工程
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DOI
高影响因子
CARBOHYDRATE POLYMERS
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2024
·
IF 10.7
Jixiao Hao,Shuai Yan,Hua Yuan,Cong Du,Yeqiang Tan
Facing the severe problem of microplastic pollution, there is an urgent need to develop biodegradable fibers to replace the petrochemical fibers. Sodium alginate , a biomass polysaccharide , has gained widespread attentions recently for the fiber manufacture. However, the limited mechanical strength of alginate fibers restricts their usages as load-bearing fabrics and reinforcement fibers . Here, we develop a novel strategy to prepare alginate multifilaments using pre-crosslinked sodium alginate solutions. The increase in the pre-crosslinking ratio effectively hinders the disentanglement of sodium alginate chains at high stretches, causing an increase in the shear viscosity of the solution ascertained from the capillarity-driven thinning process from 4.5 Pa·s to 9.9 Pa·s and facilitating the high alignment and orientation of sodium alginate chains. The resultant fibers possess a breaking strength of 474 MPa, elongation at break of 16 %, Young's modulus of 14.4 GPa, and toughness of 51.8 MJ/m 3 , exceeding most biomass fibers without reinforcement additives. The high orientation degree of 0.865 and high spinnability of alginate multifilaments enable their applications in multi-channel encryption fabrics that exhibit distinct information under various optical conditions. This rheological regulation of spinning solutions provides a facile yet effective strategy to enhance the mechanical performance and broaden application scenarios of alginate fibers.
研究领域:
材料科学
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环境科学
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生物工程
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
·
IF 8.025
Qiong Xiao,Mingze Ma,Jun Chen,Yonghui Zhang,Fuquan Chen,Huifen Weng,Anfeng Xiao
In this study, a new method for preparing macroporous rigid agarose microspheres was developed by one-step pre-crosslinking method with cyclic anhydride. Three different cyclic anhydrides, namely, maleic anhydride, succinic anhydride, and glutaric anhydride, were used to pre-crosslink agarose. The reaction temperature and the amount of cyclic anhydride in the pre-crosslinking process were optimized to endow agarose with stronger cross-linking. Under the optimal cross-linking condition, macroporous rigid agarose microspheres with homogeneous particle size were successfully obtained by adjusting emulsification method. Cryo-scanning electron microscopy was used to characterize the morphology of cross-linked agarose gel and microspheres. The addition of cyclic anhydride increased the gel aperture of cross-linked agarose microspheres, thereby making the macropores in the microspheres more dense and enhancing the mass transfer in the particles. Under low pressure , the cross-linked agarose microsphere column can effectively separate model proteins at linear flow rates three times higher than the agarose microsphere column. These results indicate that the developed agarose microspheres are a promising high-speed chromatographic medium.
研究领域:
生物化学
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材料科学
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分离技术
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DOI
PubMed
高影响因子
Polymers
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2022
·Vol. 14
·期 10
·1992
·
IF 4.967
Weijing Zhao,Jie Cao,Fucheng Wang,Fajuan Tian,Wenqian Zheng,Yuqian Bao,Kaiyue Zhang,Zhilin Zhang,Jiawen Yu,Jingkun Xu,Ximei Liu,Baoyang Lu
Stretchable, adhesive, and conductive hydrogels have been regarded as ideal interfacial materials for seamless and biocompatible integration with the human body. However, existing hydrogels can rarely achieve good mechanical, electrical, and adhesive properties simultaneously, as well as limited patterning/manufacturing techniques posing severe challenges to bioelectronic research and their practical applications. Herein, we develop a stretchable, adhesive, and conductive Ti3C2Tx-polyacrylic acid hydrogel by a simple pre-crosslinking method followed by successive direct ink writing 3D printing. Pre-polymerization of acrylic acid can be initiated by mechanical mixing with Ti3C2Txnanosheet suspension, leading to the formation of viscous 3D printable ink. Secondary free radical polymerization of the ink patterns via 3D printing can achieve a stretchable, adhesive, and conductive Ti3C2Tx-polyacrylic acid hydrogel. The as-formed hydrogel exhibits remarkable stretchability (~622%), high electrical conductivity (5.13 S m−1), and good adhesion strength on varying substrates. We further demonstrate the capability of facilely printing such hydrogels into complex geometries like mesh and rhombus patterns with high resolution and robust integration.Keywords:MXene;conductive hydrogel;3D printing;pre-crosslinking;adhesion
研究领域:
材料科学
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生物医学工程
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纳米技术
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3D打印
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DOI
PubMed
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2022
·Vol. 95
·期 3
·479-491
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IF 2.081
Lin Zhengwei,Zhang Qinghong,Wang Gongliang,Mao Jie,Hoch Martin,Shi Xinyan
Moisture crosslinking of polyolefins has attracted increasing attention because of its high efficiency, low cost, and easy processing. However, the crucial shortcoming of moisture crosslinking is that the side reaction of peroxide scorch (precrosslinking) simultaneously occurs in silane grafting. It has been recognized that making peroxide precrosslinking useful is an effective way to broaden the application of moisture crosslinking. A novel foaming process combined with moisture crosslinking is proposed. The matrix of ethylene–propylene–diene terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide as initiator. Foaming was then carried out with azodicarbonamide (AC) as the blowing agent by making use of precrosslinking. Subsequently, the EPDM-g-VTES foams were immersed in a water bath to achieve moisture crosslinking with dibutyl tin dilaurate as the catalyst. The results showed that VTES was grafted onto EPDM and the EPDM-g-VTES foams were successfully crosslinked by moisture. The EPDM-g-VTES compounds with AC obtained great cells by compression molding with the help of precrosslinking. The mechanical property of the EPDM-g-VTES foam was improved by moisture crosslinking. The moisture-cured foam with 4 wt% AC had an expansion ratio of about three times, which could bear large deformation and showed a high energy-absorption effect.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Kai Zhou,Changsheng Guo,Feng Gan,John H. Xin,Hui Yu
In existing separation membranes, it is difficult to quickly produce large-area graphene oxide (GO) nanofiltration membranes with high permeability and high rejection, which is the bottleneck of industrialization. In this study, a pre-crosslinking rod-coating technique is reported. A GO-P-Phenylenediamine (PPD) suspension was obtained by chemically crosslinking GO and PPD for 180 min. After scraping and coating with a Mayer rod , the ultra-thin GO-PPD nanofiltration membrane with an area of 400 cm 2 and a thickness of 40 nm was prepared in 30 s. The PPD formed an amide bond with GO to improve its stability. It also increased the layer spacing of GO membrane, which could improve the permeability. The prepared GO nanofiltration membrane had a 99 % rejection rate for dyes such as methylene blue, crystal violet, and Congo red. Meanwhile, the permeation flux reached to 42 LMH/bar, which was 10 times that of the GO membrane without PPD crosslinking, and it still maintained excellent stability under strongly acidic and basic conditions. This work successfully solved the problems of GO nanofiltration membranes, including the large-area fabrication, high permeability and high rejection.
研究领域:
材料科学
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纳米技术
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膜技术
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化学工程
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产品关联
DOI
PubMed
高影响因子
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