ACS Applied Polymer Materials
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2024
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IF 4.4
Yarui Hou,Xiaohui Wang,Changli Ma,Zeqi Liu,Ran Li,Yiyuan Fan,He Cheng,Bin Yang,Kai Li,Qingye Liu
Crystalline aggregates are widely present in various organisms. Regulation of nanostructures is of vital importance to the revelation of life secrets as well as material fabrication. As a representative, chitosan displays polymorphic structures. In tendon chitosan, four polymer chains are packed into an orthorhombic cell, where the antiparallel neighboring chains are linked by two sets of N2···O6 hydrogen bonds, and water molecules are connected with N2, O3, and O5 as well as O6 atoms via hydrogen bonds to stabilize the hydrated structure. The transition from hydrated to anhydrous allomorphs, however, usually involved high-temperature annealing or multistep concentrated acid hydrolysis, which weakened the sustainability of chitosan. To address these issues, we proposed a more convenient strategy to achieve the polymorphic transitions under mild conditions. By subjecting chitosan microgels (CSM) to normal freezing treatment, the hydrated aggregates could be transferred into the anhydrous form. The X-ray diffraction (XRD) results clearly demonstrated that both the (020) and (200) diffraction peaks centered at 2θ = 10 and 19.8° gradually disappeared, while the (110) peak at 2θ = 14.8° indicated the occurrence of anhydrous crystals. Upon freezing, the water molecules that were inserted into the hydrated crystals were removed. Meanwhile, under the effects of N2···O6 intermolecular hydrogen bonding and hydrophobic association, the adjacent polymer chains reorganized into new microcrystalline domains. Moreover, the CSM particles exhibited a strong tendency for self-association during this process. By introducing CSM into the oil/water mixture system to form a Pickering emulsion, the resultant macroporous materials could be used as the oil absorbent through subsequent lyophilization. This work provides a different way to facilely regulate the microcrystalline structure of chitosan in a controllable manner, facilitating the construction of more functional materials.
研究领域:
材料科学
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生物学
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产品关联
DOI
高影响因子
Environmental Science-Nano
·
2023
·Vol. 10
·期 10
·2744-2753
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IF 7.3
Jiaxin Lv,Ruixin Chen,Zhen Wu,Yang Bai,Han Song,Chen Tian,Mengye Wang,Zhang Lin
The enrichment of microplastics in polar ice is a typical phenomenon discovered in recent years. Thus, it is worthwhile to explore the degradation behavior of microplastics in frozen environments, which is crucial to evaluate their impact on polar ecosystems. Here, taking polystyrene (PS) as an example, the degradation behaviors of MPs in frozen anoxic Fe(II)-containing solutions were investigated. The results revealed that PS degradation rate in frozen solution was 14.6-fold higher than that in water. Mechanism study showed that freezing-induced aggregation and extrusion of PS enhanced the generation of environmentally persistent free radicals (EPFRs), which in turn contributed to the formation of H2O2. Moreover, freezing-induced enrichment of Fe(II) further interreacted with H2O2 to form Fe(IV) and OH free radicals at a pH of ∼6.5, and thus accelerated the degradation of PS. Such reaction was accompanied by the formation of Fe(III)-containing products, which would further react with aged PS to produce new EPFRs and Fe(II). Such cycles of aged PS/EPFRs and Fe(III)/Fe(II) continued to accelerate the degradation of PS in the frozen solution. This study provides an overlooked pathway for microplastic degradation in frozen Fe(II)-containing solutions, which would be of key importance to understand the degradation behaviors of microplastics in frozen environments.
研究领域:
环境科学
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化学
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DOI
高影响因子
Food & Function
·
2023
·Vol. 14
·期 14
·6624-6635
·
IF 6.1
Yanfang Lv,Xiaoyan Zhen,Qianqian Liang,Defu Zhang,Shumin Yi,Xuepeng Li,Jianrong Li
Polyphenols could inhibit the freezing-induced denaturation of myosin, and affect its nutritional and functional properties, which have rarely been studied to date. Therefore, the effects of interactions between polyphenols and myosin after freezing on myosin gel and digestive properties were investigated using low field NMR, a texture analyzer, a dynamic rheometer, ultraviolet–visible spectra, scanning electron microscopy, LC-MS/MS, an automatic amino acid analyzer, etc. Hesperetin (HE), dihydroquercetin (DI), salidroside (SA), and mangiferin (MA) increased the water-holding capacity, non-flowable water content, gel strength, texture, storage modulus, and fractal dimensions of the myosin gel, while modifying its leading force. The results of scanning electron microscopy revealed that the surfaces of polyphenol groups were relatively smoother than those of the control group. Meanwhile, the four types of polyphenols under study significantly improved the gastric and gastrointestinal digestibility of myosin. Furthermore, they significantly increased the contents of essential, flavor, and total free amino acids, as well as the unique peptide numbers in myosin digestion products. This work provides reliable guidance for polyphenols to improve protein function and nutritional properties.
研究领域:
食品科学
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生物化学
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营养学
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DOI
PubMed
高影响因子
ACS Applied Polymer Materials
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2024
·
IF 4.4
Hongyu Yin,Ran Wei,Xiang Zhang,Changsheng Zhao
Traditional poly(ether sulfone) (PES) membranes and spheres exhibit asymmetrical and non-interconnected porous structures, which results in relatively low mass transfer efficiency and thus limits their applications in separation and adsorption to some extent. In this work, PES-based monolithic materials are fabricated by a simple method termed freezing-induced phase separation (FIPS). The as-prepared monoliths show a uniform and interconnected porous structure, high porosity (73.11–83.32%), and good mechanical properties (Young’s modulus higher than 3.70 MPa). A hydrophilic copolymer (poly(2-aminoethyl methacrylate)─PAMA) of acrylic acid (AA) and methyl methacrylate (MMA) is introduced into the monolith, which improved the hydrophilicity and endowed the modified PES-based monolith with a negatively charged surface. The pseudo-ternary PES/PAMA, EtOH, and N,N-dimethylformamide (DMF) systems are studied. The monoliths show a denser and more uniform porous structure when a relatively high PES concentration and PAMA amount are used. The adsorption capacity of monoliths for methylene blue (MB) increases with increasing PAMA content, from 10.26 to 64.38 mg/g. Meanwhile, the adsorption capacity can be further improved by hot water post-treatment, from 64.38 to 108.33 mg/g. Batch adsorption tests indicate that the adsorption behavior of the MB monoliths fit the pseudo-second-order kinetic and Langmuir isotherm models. The dynamic adsorption results indicate that the monoliths could remove MB rapidly and effectively. In addition, the modified PES-based monolith selectively adsorb the cationic dyes in a mixed dye solution and has good recyclability.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2025
·
IF 6.2
Yaofang Fan,Yu Liao,Zhiying Gao,Haoran Wang,Yong Li,Chao Shi,Cuiping Ma
A DNA electrochemical interface biosensor based on screen-printed carbon electrodes (SPCEs) holds promise for point-of-care testing (POCT) detection of pathogens in food safety. Nevertheless, SPCE commonly has a rough surface and suffers from a relatively low electron transfer rate, disorder of DNA capture probes (CPs), and the steric hindrance effect of target nucleic acid binding. These issues lead to a low sensitivity. Herein, a simple and rapid electrochemical biosensor based on N-doped porous carbon (NPC)-modified SPCE and freezing-directed DNA combined with catalyzed hairpin assembly (CHA) was constructed for the one-pot detection of pathogens in food samples without time-consuming growth cultures. The biosensor was constructed by SPCE modified with NPC for enhanced electrochemical properties, and the DNA CP designed for CHA was stably fixed on the electrode for a high hybridization efficiency. Moreover, the signals amplified by CHA enable the selective and sensitive detection of pathogens without washing steps. This one-pot method is simple and sensitive with a wide detection linear range of 101 to 107 CFU/mL and limit of detection of 5 CFU/mL for Escherichia coli and shows specificity against other coexisting pathogens. The whole detection of pathogens in complex samples is performed only within 60 min from sample-to-answer, which has great potential for POCT of pathogens in food safety.
研究领域:
食品安全
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生物传感
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分子诊断
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）