SCIENCE OF THE TOTAL ENVIRONMENT
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2024
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IF 8.2
Qiyin Tan,Yue Shen,Jiahao Sun,Tao Jian,Wen Lu,Sijin Wu,Zengjian Zhao,Qian Lei,Hongjun Lin
Organics and divalent cations are the primary barriers constraining the performance of membrane technology, while the interactions between them and the detailed mechanisms of their impacts are still lacking in-depth analysis. In this study, sodium alginate and xanthan gum were selected as polysaccharides models, and the formation of transparent extracellular polymer particles (TEP) was assessed to examine the effect of Ca 2+ and polysaccharides type on membrane fouling from both qualitative and quantitative perspectives. The results revealed that higher Ca 2+ concentrations led to a greater abundance of TEP, and the transformation of TEP microstructure is a key factor for the membrane fouling change indicated by specific filtration resistance (SFR). TEP formed by sodium alginate underwent a transformation from amorphous-TEP (a-TEP) form to particle-TEP (p-TEP), corresponding to a unimodal pattern of SFR variation. With increasing Ca 2+ concentration, the molecular interactions of xanthan gum became stronger, resulting in larger fibrous a-TEP and a continuous SFR increase. According to the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, TEP formed by xanthan gum exhibited higher adhesion energy, thus causing more severe membrane fouling. The SFR variation of the TEP system can be satisfactorily explained by the conception of chemical potential change in the filtration process depicted in Flory-Huggins theory. This study is the first work to introduce models regarding chemical potential and TEP microstructure, linking the system chemical potential and TEP microstructure with membrane fouling indicated by SFR. As all, this study provided a new perspective for analyzing the polysaccharide fouling behavior via TEP determination and further enhanced the understanding through thermodynamic analysis.
研究领域:
环境科学
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生物学
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产品关联
DOI
PubMed
高影响因子
WATER ENVIRONMENT RESEARCH
·
2025
·Vol. 97
·期 7
·e70121
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IF 1.9
Zhi-Ke Wang,BaoFen Sun,Ting-Ting Li
In this study, an adsorbent capable of rapidly adsorbing heavy metal ions was prepared using PVA crosslinked with PF127DA and AA/AM. The swelling behavior of the hydrogel in salt solutions was investigated based on the Flory–Huggins theory model. The results indicated that the theoretical predictions of the hydrogel's volume swelling ratio, derived from the Flory–Rehner swelling theory and the Donnan equilibrium, were in agreement with the experimental swelling data of the hydrogel in water and salt solutions. With the increase in the amount of crosslinking agent PF127DA, the water absorption swelling ratio of the composite material was reduced by half, with the volume swelling ratio decreasing from 3.56 to 2.33. When the concentration of cations in the salt solution increased from 10 −5 mol/L to 10 −1 mol/L, the volume swelling ratio of the hydrogel showed a decreasing trend, which in turn affected the adsorption performance of the pollutant. Therefore, increasing the amount of crosslinking agent can enhance the colloidal strength, provided that its swelling properties are not compromised. Additionally, the presence of high concentrations of salt can affect the adsorption behavior of the hydrogel, and appropriate measures should be taken in practical applications to avoid its impact on adsorption behavior. Graphical The study prepared adsorbent, analyzed PF127DA's effect on hydrogel, and found it affects swelling and has high Pb adsorption capacity for heavy metal removal.
研究领域:
材料科学
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环境科学
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高分子化学
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化学工程
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产品关联
DOI
PubMed
高影响因子
LANGMUIR
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2020
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IF 3.557
Chuyi Liao,Chungen Hsu,Xiaogong Wang
This study focused on mussel-like surface adhesion and photoinduced cooperative deformation of a unique type of Janus particles (JPs), composed of an isosorbide-based molecular glass bearing push–pull type azo chromophore (IAC-4) and a 2,6-pyridinedicarboxamide-containing poly(dimethylsiloxane) oligomer (H2pdca-PDMS). The JPs were obtained by the solvent evaporation method in an aqueous medium with the dispersed phase of a solution of IAC-4 and H2pdca-PDMS in dichloromethane (DCM). The JP formation and its mechanism were investigated by electron microscopy, in situ optical microscopy, and theoretical analysis. The results showed that the Janus structures form through gradual segregation between the two components in the droplets induced by the evaporation of DCM, which follows the ternary phase diagrams calculated according to Flory–Huggins theory. In the following stage, the gradual coalescence of small domains in droplets is controlled by dynamic factors. After being deposited on a substrate, the JPs exhibit unidirectional adhesion with the H2pdca-PDMS parts spreading on the substrate, while the IAC-4 parts orientate away from the substrate. The mussel-like adhesion is caused by the interfacial interaction of H2pdca-PDMS with the hard surfaces (i.e., glass and silicon substrates) and its strong ability to spread and wet the surfaces to increase the contact area with the surfaces. Upon irradiation with linearly and circularly polarized laser beams at 488 nm, respectively, a series of unique surface morphologies are observed because of the photoinduced deformation of the IAC-4 parts along the electric vibration direction of the polarized light and the cooperative deformation of the H2pdca-PDMS parts of the JPs. The cooperative deformation reveals the strong interfacial interaction and cohesiveness between the IAC-4 and the H2pdca-PDMS phases in JPs. No peeling-off from the substrate is observed after the large-scale deformation, which also indicates the strong adhesion of the JPs on the substrate surfaces. This study not only demonstrates the mussel-like adhesion and unique cooperative deformation behavior but also supplies new insights into the interfacial interaction in JPs as well as that with hard surfaces, thus opening a new avenue for surface modification and functionalization.
研究领域:
材料科学
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表面化学
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纳米技术
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2021
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IF 8.742
Xixia Liu,Xingchen Lu,Zonghuan Wang,Xiaohui Yang,Guangli Dai,Jun Yin,Yong Huang
Poly(lactic- co -glycolic acid) (PLGA) is a widely used polymeric biomaterial due to its excellent biocompatibility and biodegradation. Asymmetric PLGA hollow fiber membranes (HFMs) have been extensively used as porous tubular scaffolds for tissue engineering , e.g. for nerve conduits and artificial blood vessels . PLGA HFMs are generally fabricated through a dry-jet wet spinning process, and the porous morphology of PLGA HFMs induced by polymer/solvent/nonsolvent ternary phase inversion plays a key role in their biomedical performance. In this study, PLGA was dissolved in dimethyl sulfoxide (DMSO) as the dope fluid, and deionized water with different DMSO contents was used as the bore fluid. The influence of bore fluid composition on the HFM morphology and performance was investigated by measuring phase separation time, porosity, mechanical properties , and in vitro hydrolytic degradation. The results indicated that with increased bore fluid DMSO content, the inner and outer diameters, as well as the wall thickness of the HFMs, decreased significantly; also, the inner surface became more porous and the inner surface pore size and porosity increased. Cross-sectional SEM images showed that the middle layer of the five-layered microstructure gradually changed from large voids to finger-like microvoids when the DMSO content in bore fluid increased from 0% to 60%. Furthermore, the HFMs resulting from higher DMSO content in bore fluid had a lower porosity, a faster degradation rate, a higher Young's modulus , and a lower suture retention strength . More importantly, the in vitro cell culture on the inner surface of PLGA HFMs showed that PC12 cells cultured on HFMs prepared with 60% DMSO bore fluid exhibited better cell adhesion, longer neurite length, and alignment along the HFM longitudinal axis. A ternary phase diagram and the Flory-Huggins theory were applied to analyze HFM morphological formation. The study contributes to understanding of the mechanism of HFM porous morphology formation and should guide potential application of PLGA HFMs as tissue engineering scaffolds.
研究领域:
材料科学
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生物医学工程
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组织工程
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生物材料
✓ 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）