ACS ES&T Engineering
·
2021
·
IF 0
Jiayu Tian,Xiujuan Hao,Xinglin Lu,Shanshan Gao,Ruijun Zhang,Songxue Wang,Fuyi Cui
Biofouling is a major challenging issue to be addressed for the successful application of thin-film composite (TFC) polyamide (PA) membranes. In this work, we demonstrated that the presence of divalent cations, especially Ca2+, can intensively aggravate the biofouling on the TFC PA membrane using Escherichia coli and Staphylococcus aureus as model bacteria. To figure out the key surface characteristics of the TFC membrane facilitating the biofouling upon Ca2+ addition, the PA layer was modified by in situ addition of carboxylated chitosan (CCTS) during interfacial polymerization (IP), which induced the increase of surface carboxyl groups, improvement of hydrophilicity, and reduction of surface roughness. By conducting biofouling tests, the importance of carboxyl groups on the membrane surface and their interaction with bacteria via Ca2+-carboxyl bridging in biofouling was verified. The water flux decreased to 49.5% (TFC-control) and 41.6% (TFC-CS (0.3)) of the initial water flux, respectively. Furthermore, by preoccupying carboxyl groups on the PA layer via in situ Ca2+ addition during IP reaction, it was found that reducing the carboxyl density of the PA layer can markedly inhibit the adhesion of bacterial on TFC membrane surface, the water flux only decreased by only 35.6% relative to the initial water flux, thus effectively mitigating biofouling of TFC membranes. This work provides a new pathway for better understanding and control of biofouling in the design and application of TFC PA membranes.
研究领域:
环境科学
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材料科学
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微生物学
✓ 已验证
产品关联
DOI
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Yanlei Hu,Mengyue Shi,Liang Liu,Juan Yu,Yimin Fan
Bionanomaterial based hydrogels originated from natural biopolymer have drawn much attention for advanced applications. However, nanosilk-based hydrogels derived from top-down approaches remain in their infancy. First, nanosilks based on existing methods fail to prepare hydrogels; second, both nanosilk extraction and surface modification remain a challenge due to high crystallinity and sophisticated hierarchical structures. To produce nanosilk-based hydrogels, pretreatment and oxidation are necessary. In this work, pretreatments were conducted first to loosen the sophisticated structures of natural silk fibers, NaClO oxidation was utilized in succession to introduce carboxyl groups onto silk fibroin . Combined with moderate mechanical disintegration, silk nanocrystals with additional carboxyl groups were prepared facilely. Finally, silk nanocrystal-based hydrogels were prepared successfully through gas phase coagulation. An optimization of pretreatment approaches and oxidation conditions was carried out. The morphologies, chemical and crystalline structures of original, pretreated and oxidized silk fibroin as well as nanofibrillated silk were investigated. In addition, the silk nanocrystal-based hydrogel exhibited outstanding mechanical properties compared to those of dissolved and regenerated silk fibroin-based hydrogels. Moreover, silk nanocrystal-based aerogels present highly porous, interconnected, and crisscrossed network nanostructures, which are ideal candidates for tissue regeneration and provide new prospects as porous scaffolds for bioengineering applications.
研究领域:
生物材料学
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纳米技术
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组织工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2014
·Vol. 49
·期 6
·2672-2679
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IF 2.305
Fan Xianzhong,Shang Kun,Sun Bing,Chen Lijian,Ai Shiyun
A Sm 3+ complex, tris-(2-thenoyltrifluoroacetone) mono-1,10-phenanthroline-Sm 3+ [Sm(TTA) 3 (Phen)], can be easily integrated in situ via covalent functionalization to surface-carboxylated graphene oxide (GO-COOH) from a ethanol solution. The Sm 3+ containing material has been comprehensively characterized via Fourier transform infrared spectra, X-ray photoelectron spectroscopy, UV–Vis absorption spectra, luminescence spectra, transmission electron microscopy, powder X-ray diffraction, thermogravimetric analysis (TG and DTG). The integration of rare earth complexes (RE) onto GO-COOH, as well as the individual nature of the hybrids, is confirmed. The GO-COOH with high load capacity can integrate more RE than GO. The brilliant optical properties of the GO-COOH-RE complex hybrids make them promising candidates applying in many practical fields, such as biomedical applications.
研究领域:
材料科学
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光学
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生物医学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xuechao Xu,Juanli Yang,Qiao Guo,Lu Gao,Bo Wang,Suhui Tan,Kun Wang,Yun-xia Li,Shengyan Zhao,Yi Li,Zhen-quan Yang
Reassessment of total antioxidant capacity (TAC) in Cordyceps militaris is imperative for providing dietary guidance and facilitating health monitoring. Herein, surface-carboxylated cobaltous oxide (COOH-Co 3 O 4 ) nanozyme was achieved via a dual-stage procedure encompassing reduction preparation and surface modification. COOH-Co 3 O 4 exhibited exceptional oxidase-like activity under neutral pH conditions, facilitating conversion of dissolved oxygen into superoxide anion free radicals and subsequently catalyzing oxidation of colorless 3, 3′, 5, 5′-tetramethylbenzidine (TMB) to yield blue oxidized TMB (TMBox) at neutral pH. Additionally, antioxidants can eliminate O 2 · − produced in the above reaction system. Moreover, the absorbance at 652 nm of the COOH-Co 3 O 4 + TMB reaction system gradually diminishes with an increase in ascorbic acid concentration. Based on it, a colorimetric evaluation system (using ascorbic acid as a reference) for TAC of C. militaris was established. This innovative approach offers an impressively low limitation of detection (LOD) calculated as 0.78 μM. Furthermore, it was employed to evaluate TAC of real C. militaris samples, yielding a satisfactory recovery (96.1 %–102.3 %), thereby demonstrating its exceptional accuracy. The TAC of C. militaris extracted using different solvents was determined, indicating that the highest TAC is observed in C. militaris extracted by deionized water. This study not only offers a rapid, cost-effective, and convenient analytical tool for evaluating TAC of C. militaris but also expands the potential applications of nanozymes.
研究领域:
食品科学
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生物化学
✓ 已验证
产品关联
DOI
高影响因子
Regenerative Biomaterials
·
2022
·
IF 5.763
Deng Di,Fu Shengxiang,Cai Zhongyuan,Fu Xiaomin,Jin Rongrong,Ai Hua
Macrophage autophagy is a common biological response triggered by nanomaterials, which is closely related to the regulation of inflammation. Superparamagnetic iron oxide (SPIO) nanoparticles have been used for study of autophagy response due to their broad biomedical applications. However, few reports have focused on how to regulate the macrophage autophagy response induced by SPIO nanoparticles. In this study, SPIO nanoparticles grafted with carboxyl groups were synthesized and for the comparison of macrophage autophagy with unmodified nanoparticles. The study on the correlation between autophagy and inflammation induced by the two kinds of SPIO nanoparticles was also included, and the one that grafted with carboxyl groups shows a reduction of autophagy and thereby caused a milder inflammatory response. We proposed that the increased amount of albumin adsorption on the surface of carboxylated SPIO nanoparticles, a protein previously proven to attenuate autophagy, can be considered an important reason for reducing autophagy and inflammation. In general, the carboxyl modification of SPIO nanoparticles has been demonstrated to reduce inflammation by inhibiting macrophage autophagy, which may provide some insights for the design of nanomaterials in the future.
研究领域:
纳米技术
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生物医学工程
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2019
·
IF 6.035
Yuchen Wu,Mingfu Gao,Weitao Chen,Zhenhua Lü,Sanchuan Yu,Meihong Liu,Congjie Gao
In this work, nanofiltration membrane with an asymmetric selective separation layer and improved surface negative charge was designed and fabricated to efficient remove anionic dyes from aqueous solution. Firstly, loose polyester selective separation layer was formed through interfacial polymerization of triethanolamine and trimesoyl chloride. Surface carboxylation was then implemented via esterification using poly(acrylic acid) to generate a dense skin. Membrane characterizations verified the asymmetric structure and enrichment of surface carboxyl group, which endowed the carboxylated membrane with improved perm-selectivity and anti-dye-deposition property to anionic dye aqueous solutions. The desired surface carboxylated membrane exhibited 99.6% methyl blue removal, 8.05 l/m 2 h bar steady-state water permeability and 14.3% relative flux decline ratio under 5.0 bar. The water permeability of carboxylated membrane to methyl blue aqueous solution was higher than those of most reported membranes and even at least two times higher than that of the polyester-based membrane having nearly the same dye removal ability. The attractive results indicate that surface carboxylated polyester based thin-film composite membrane is a promising material for high-efficiency nanofiltration of anionic dye aqueous solution. This study provides valuable insights into the construction and fabrication of high performance nanofiltration membrane for efficient treatment of anionic dye aqueous solution.
研究领域:
环境工程
·
膜科学与技术
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水处理
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材料化学
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纳米技术
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分离科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Ning Pan,Debin Guan,Yuntao Yang,Zhenling Huang,Ruibing Wang,Yongdong Jin,Chuanqin Xia
We report a rapid, environmentally-friendly and cost-effective route for the preparation of a graphene-based nanomaterial, carboxyl graphene (aka. reduced graphene oxide , RGO) from graphene oxide (GO). Carboxyl graphene was prepared on the scale of several grams through the reduction of GO by thiourea dioxide (TUD) at a relatively low temperature (40 °C) in an alkaline medium (pH = 10). The reduction of GO was confirmed by FT-IR, UV–vis, X-ray photoelectron, and Raman spectroscopy. In addition, this reduction was also confirmed by thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Characterizations of these materials demonstrated that selective reduction of the epoxy and carbonyl groups occurred on the surface of GO, while carboxyl groups were left behind. In addition, the conjugation of the carbons in the structure was restored through this reduction and a single-layer of carboxyl graphene (with a thickness of 0.80 nm, as observed by AFM) was obtained under these conditions. Carboxyl graphene had a high surface area (of 454.52 m 2 g −1 ) and contained approximately 6.9 ± 1.6 mmol of carboxyl groups per gram of material, as determined via Boehm titration. The mechanism for selective reduction of the epoxy and carbonyl groups on GO to form carboxyl graphene by TUD is proposed and discussed in detail.
研究领域:
纳米材料化学
·
材料科学
·
表面化学
·
碳基纳米材料
·
功能化纳米材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）