JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Rongze Sun,Jianlong Dai,Danrong Cai,Wentao Yan,Yong Zhou,Congjie Gao
Xylose is a small organic molecule with great economic value in fine chemical production. High-quality xylose production requires removing salt from the feed solution, which is typically an expensive process. Polyamide nanofiltration membranes, characterized by their high rejection of salts (e.g., Na 2 SO 4 ) and low rejection of small organic molecules (such as xylose), are an effective separation technique. The present study proposes a CTAB-assisted shedding strategy toward polyamide oligomers to enhance the xylose/salt separation. When the membrane contacts CTAB solution at appropriate concentrations, CTAB aggregates adsorb onto the membrane surface due to electrostatic and hydrophobic interactions. The hydrophilic outer layer of these aggregates, attributed to the quaternary ammonium groups, facilitates the migration of polyamide oligomers into the solution, increasing membrane pore size and thereby decreasing xylose rejection. This mild process preserves the membrane structure and its strong negative charge, maintaining effective charge repulsion and ensuring high salt rejection. The increased pore size also enhances membrane flux. Results show that xylose rejection decreased from 44.2 % to 20.3 %, while Na 2 SO 4 rejection remained above 98 %. The separation factor increased by 117 %, and flux increased by 104 %. Investigation of the shedding mechanism revealed that the variation of membrane flux with CTAB concentration aligns with the S-shaped adsorption isotherm model of surfactants at the solid-liquid interface. This suggests that the adsorption form of CTAB on the membrane surface is the dominant factor influencing this process. This work shows the promising potential of polyamide nanofiltration membrane technique for the xylose purification and the proposed strategy in small organic molecule/salt separation.
研究领域:
化学工程
·
膜科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Kai Sun,Xing Cheng,Jialin Yu,Luojian Chen,Jiajun Wei,Wenjun Chen,Jun Wang,Shunyao Li,Qingzhu Liu,Youbin Si
Estrogens, which are extensive in the eco-environments, are a category of high-toxic emerging contaminants that induce metabolic disorders and even carcinogenic risks in wildlife and humans. Here we investigate whether fungus-secreted laccase can be used as a green catalyst to eliminate a representative estrogen, 17 β -estradiol (E2). A white-rot fungus Trametes hirsuta La-7 with high laccase-productivity, was isolated from pig manure-contaminated soil. Extracellular laccase activity expressed by strain La-7 was 65.4 U·mL −1 for a 3 d inoculation under the optimal fermentation parameters. The concentrated-crude laccase from Trametes hirsuta La-7 (CC- Th Lac) was capable of effectively metabolizing E2 at pH 4–6, and the apparent pseudo first-order reaction rate constant and half-life values were respectively 0.027–0.055 min −1 and 25.86–12.67 min ( R 2 > 0.98). The mass measurement of high-resolution mass spectrometry in combination with 13 C-isotope labeling identified that the main by-products of E2 metabolism were dimers, trimers , and tetramers, which are consistent with radical-driven C–C and/or C–O–C covalent coupling pathway, involving the initial enzymatic production of phenoxy radical intermediates and then the successive oxidative-oligomerization of radical intermediates. The formation of oligomers dramatically reduced the estrogenic activity of E2. Additionally, CC- Th Lac also exhibited high-efficiency metabolism capability toward E2 in the natural water and pig manure, with more than 94.4% and 91.0% of E2 having been metabolized, respectively. These findings provide a broad prospect for the clean biotechnological applications of Trametes hirsuta La-7 in estrogen-contaminated ecosystems.
研究领域:
环境生物学
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生物化学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Jing Yang,Changzhi Shi,Chaoran Xu,Yankai Zhang,Zhuolan Zhang,Maoyong Song,Qiqing Chen,Zimeng Wang,Xiangcheng Pan,Mingliang Fang
Polylactic acid (PLA) is the most widely consumed biodegradable plastic worldwide. Though PLA products have the advantages of easy degradation and a small carbon footprint, poly(lactic acid) oligomers (OLAs) released from PLA have been found to exhibit toxicity. Accurate quantification of the presence of the OLAs in soil is crucial for understanding their occurrence and environmental fate. In this study, we synthesized sequence-defined OLA standards and deuterated OLAs (d-OLAs) and developed a broad-spectrum extraction method with water-saturated ethyl acetate and 0.1% formic acid, achieving sensitive and precise quantification of the OLAs across various soil environments. The simulated experiments showed that PLA-based products released amounts of OLAs, reaching their peak within 24 h, followed by degradation, with the OLAs remaining detectable in the soil for up to 168 h. Meanwhile, the OLA with a degree of polymerization (DP) of 2 exhibited the highest concentration, while higher-DP OLAs demonstrated greater stability in soil compared to others. In the field samples, OLAs were detected in soil over the long term beneath PLA-based biodegradable mulch films with residual concentrations reaching up to 16.10 ± 0.37 ng/g. This study bridges foundational analytical methods and addresses data gaps for further investigations into the environmental fates of the OLAs and PLA.
研究领域:
环境科学
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分析化学
·
生物降解材料研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2020
·
IF 3.594
Songyang Feng,Sheng Xiang,Xinchao Bian,Gao Li
In aqueous solutions of concentrated lactic acid (>30 wt%), oligomers of lactic acid can produce via the intermolecular esterification of lactic acid, and thus the amount of titratable acidity is often less than that of total acidity. In this paper, the hydrolysis of oligomers of lactic acid was investigated at different temperatures in detail. The experimental results showed that when the content of total acidity is lower than 30 wt% in aqueous lactic acid solutions, the oligomers of lactic acid can been completely hydrolyzed to give monomeric lactic acid and the monomeric lactic acid is stable at temperatures of 8–33 °C, thus the total acidity is equivalent to the titratable acidity and can be determined quantitatively by a direct potentiometric titration. The results for determining total acidities were in good agreement with those obtained from a back titration by a two tailed t -test. Compared with the back titration, the novel method's procedure is simpler and reducing sugars do not interfere with measurements. The relative standard deviation ( RSD ) was less than 0.7% and 1.1% for the direct potentiometric and back titrations, respectively, which indicated that the direct potentiometric titration has a higher precision.
研究领域:
分析化学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Ruiqi Li,Yudan Wang,Dan Zhou,Lijia Liu,Junqing Li,Yufa Li,Jijin Dai,Yushan Han
The polymerization of aniline (AN) was assisted with an oligomer that possessed two amino end groups ( 2AO ) in the presence of a single enantiomeric acid, (1 S )-(+)-10-camphorsulfonic acid (( S ) CSA). The reaction produced helical polyaniline (PANI) nanofibers with the opposite helical sense due to the concentration changes of ( S ) CSA in the polymerization system. The similar dependence of the circular dichroism (CD) signal on the ( S ) CSA concentration was also observed in the oxidization of the oligomer 2AO by ammonium persulfate (APS) in the presence of ( S ) CSA. In addition, under a certain ( S ) CSA concentration, the 2AO- assisted polymerization at low and high temperatures also produced the PANI fibers with the opposite helical sense. It is likely that these result from the different interaction modes of ( S ) CSA with the 2AO at different ( S ) CSA concentration. As a consequence, the oxidized 2AO (oligomer seeds) with different chirality in the early stage of the polymerization control the helicity of the resulting PANI nanofibers.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2024
·
IF 3.6
Hongxia Chen,Hao Zhou,Zhiwen Qi,Xingying Xue,Chengzhang Wang
There have been studies published on the composition and coating uses of raw lacquers following enzymatic oxidative polymerization. The change of urushiol’ thermal stability and biological activity following polymerization to create oligomer, however, has received little attention. This work using silica gel column chromatography to separate urushiol and urushiol oligomer from polymerized raw lacquer and assessed its antibacterial, antioxidant, and thermal stability in an effort to decrease the allergenicity of urushiol and increase its application. By using gel chromatography, the urushiol oligomer were discovered to be polymers with 2–5 degrees of polymerization. According to characterization results from techniques like UV, FT-IR, and 1H NMR, urushiol was converted into urushiol oligomer by addition reactions, and C–C coupling. The findings demonstrated that the urushiol oligomer’ IC50 values for scavenging DPPH and ABTS free radicals were 40.8 and 27.4 μg/mL, respectively, and that their minimum inhibitory concentrations against Staphylococcus aureus and Staphylococcus epidermidis were 250 and 125 μg/mL. The urushiol oligomer’s thermogravimetric differential curve peak temperature (461.8 °C) was higher than urushiol’s (239.5 °C), indicating that urushiol undergoes polymerization with enhanced thermal stability. The study’s findings establish a foundation for the use of polymerized urushiol and urushiol oligomer in applications including functional materials and additives.
研究领域:
材料科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 25
·11371-11379
·
IF 3.591
Zheming Zhang,PingPing Jiang,Dekai Liu,Shan Feng,Yan Leng,Pingbo Zhang,Agus Haryono,Zhenhua Li,Yuchao Li
With increasing attention to the environment and health, the demand for environmentally friendly plasticizers, which were applied to produce phthalate-free flexible poly(vinyl chloride) (PVC), is becoming more and more urgent. In this work, a novel high efficiency plasticizer, an ester-capped oligomeric lactic acid mixture (EOL), was successfully synthesized by a two-step esterification reaction, with L-lactic acid as the main raw material. The structure of EOL was characterized by using FT-IR, 1H NMR and time of flight mass spectrometry (TOF-MS). The plasticizing performance of EOLs in PVC was tested and compared with those of commercial environmental plasticizers acetyl tributyl citrate (ATBC) and di-2-ethylhexyl terephthalate (DOTP). According to the results of tensile tests, the elongation at break of PVC plasticized by 50 phr EOLs reached 725.5%, indicating its superior mechanical properties. The result of TGA showed that the thermal stability of PVC plasticized by EOLs was as comparable as that of PVC plasticized by DOTP or ATBC. Furthermore, compared with ATBC and DOTP, EOLs showed better migration resistance in the leaching test. All test results showed that the comprehensive performance of EOLs was better than those of commercial green plasticizers ATBC and DOTP, which provided a new method for the development of novel green plasticizers.
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
LIQUID CRYSTALS
·
2012
·
IF 1.858
Fafu Yang,Jianwei Xie,Hongyu Guo,Bingting Xu,Congcong Li
Series of novel 1,3,5-triazine-based triphenylene oligomers 7, 10 and 12 with large bridging polyaromatic core were designed and synthesised by simple procedures in high yields. Their structures were confirmed by FTIR, 1H NMR, ESI-MS and elemental analyses. Their mesomorphic behaviours were studied by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. 1,3,5-triazine-based triphenylene monomer 7 has no mesomorphic property, but 1,3,5-triazine-based triphenylene dimer 10 and 1,3,5-triazine-based triphenylene trimer 12 possess excellent mesomorphic properties. The mesomorphic temperature range of compound 12 was as wide as 180°C. These studies indicated that the mesomorphic properties were determined by the numbers of triphenylene units. More units of triphenylene in the oligomers resulted in better mesomorphic properties.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2018
·
IF 3.193
Yi Wen,Zhou Cheng,Wenxiong Li,Zhi Li,Duijun Liao,Xiaoping Hu,Ning Pan,Deyi Wang,T. Richard Hull
A novel oligomer (PFDCHQ) based on 9,10-dihydro-9-oxa-10-phosphaphenanthrene −10-oxide (DOPO) and ferrocene groups was synthesized successfully, aiming at improving the flame retardant efficiency of diglycidyl ether of bisphenol A epoxy resin (DGEBA). FTIR , 1 H NMR and 31 P NMR were used to confirm the chemical structure of PFDCHQ. The high char yields of 60.3 wt% and 20.1 wt% were obtained for PFDCHQ from TGA results in nitrogen and air atmosphere, respectively. The thermal degradation mechanism of PFDCHQ was investigated by TG-FTIR and Py-GC/MS. The limiting oxygen index (LOI) of EP-5 with 5 wt% loading of PFDCHQ increased to 32.0% and the UL-94 V-0 rating was achieved, showing a notable blowing-out effect. In contrast to EP-0, the peak of the heat release rate (pHRR) and total heat release (THR) of EP-5 decreased by 18.0% and 10.3%. The flame retardant mechanism of PFDCHQ in epoxy resin was studied by TG-FTIR, SEM and Raman. SEM and Raman results indicated the formation of coherent and dense char residue with high degree of graphitization due to the incorporation of PFDCHQ. In UL-94, the blowing-out effect dominantly accounted for the enhanced flame retardancy in combination with optimized char structure. Furthermore, the addition of PFDCHQ improved the Young's modulus compared to EP-0.
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
HIGH PERFORMANCE POLYMERS
·
2015
·
IF 1.286
Lu Sun,Wei Wang,Lubo Xu,Guofei Chen,Xingzhong Fang
A series of oligomers based on the mixture of thioetherdiphthalic anhydride isomers and 4,4′-oxydianiline with 4-phenylethynylphthalic anhydride as reactive endcapping reagent were prepared. The calculated molecular weights were in the range of 1150–5070 g mol−1 with different degrees of polymerization (n = 1, 3, 5, 7, and 9). The effect of molecular weight of the aromatic oligomers on their processability and solubility as well as the thermal and mechanical properties of the thermal-cured polyimides (PIs) was systematically investigated. The typical oligomer (Oligo-1) could be melted at temperatures of 289–334°C to yield stable molten fluid with melt viscosity below 1.0 Pa s. The melt viscosity of the oligomers increased with the increasing molecular weight. After thermally curing at 370°C, the thermoset PIs exhibited good thermal properties. The glass transition temperatures of oligomers measured by differential scanning calorimetry were in the range of 286–326°C, and the temperature of 5% weight loss was higher than 524°C. The cured films also showed good mechanical properties with tensile strength above 72 MPa and modulus more than 2.5 GPa.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
NATURE
·
2019
·Vol. 574
·期 7778
·394-398
·
IF 43.07
Liu Zhaoming,Shao Changyu,Jin Biao,Zhang Zhisen,Zhao Yueqi,Xu Xurong,Tang Ruikang
Inorganic materials have essential roles in society, including in building construction, optical devices, mechanical engineering and as biomaterials 1 , 2 , 3 , 4 . However, the manufacture of inorganic materials is limited by classical crystallization 5 , which often produces powders rather than monoliths with continuous structures. Several precursors that enable non-classical crystallization—such as pre-nucleation clusters 6 , 7 , 8 , dense liquid droplets 9 , 10 , polymer-induced liquid precursor phases 11 , 12 , 13 and nanoparticles 14 —have been proposed to improve the construction of inorganic materials, but the large-scale application of these precursors in monolith preparations is limited by availability and by practical considerations. Inspired by the processability of polymeric materials that can be manufactured by crosslinking monomers or oligomers 15 , here we demonstrate the construction of continuously structured inorganic materials by crosslinking ionic oligomers. Using calcium carbonate as a model, we obtain a large quantity of its oligomers (CaCO 3 ) n with controllable molecular weights, in which triethylamine acts as a capping agent to stabilize the oligomers. The removal of triethylamine initiates crosslinking of the (CaCO 3 ) n oligomers, and thus the rapid construction of pure monolithic calcium carbonate and even single crystals with a continuous internal structure. The fluid-like behaviour of the oligomer precursor enables it to be readily processed or moulded into shapes, even for materials with structural complexity and variable morphologies. The material construction strategy that we introduce here arises from a fusion of classic inorganic and polymer chemistry, and uses the same cross-linking process for the manufacture the materials.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2024
·
IF 4.8
Linyi Shui,Lintao Zhou,Xianxin Guo,Guohua Chen,Xiaomin Zhao
Polymer/transition metal inorganic salts nanocomposites are promising engineering materials in automotive, electronics, aerospace and smart wearables fields. However, the interfacial incompatibility always causes agglomeration and phase separation, constraining their further application. Inspired by inorganic oligomers' polymerization, nylon/nickel phosphate oligomer (NPO) nanocomposite (ENCC) was prepared via hydrogen bond crosslinking method. Due to the formation of hydrogen bonds between PO 4 3− end groups of NPO with an average diameter of 6.5 ± 1.2 nm and NH groups on the nylon molecular chain, the phase compatibility is greatly improved. Hence, NPO was uniformly nano-dispersed and had no obvious agglomerate in ENCC, inducing an invisible phase interface at nano-micro scale. Nylon/nickel phosphate oligomer showed an excellent reinforcing effect on nylon, the tensile strength and elongation of ENCC reached 28 ± 0.8 MPa and 585 ± 26% at a high loading of 20 wt%, increased by 155% and 92%, compared with pure matrix, respectively. Furthermore, ENCC was still optically transparent and had excellent anti-blue-light performance (up to 96.6%). Highlights Novel inorganic/nylon composite prepared by hydrogen bond crosslinking method. Phase separation and aggregation problems were solved remarkably. Inorganic metal phosphate dispersed with a diameter of 6.5 ± 1.2 nm. The composite was still transparent at 20 wt% loading of metal phosphate. Tensile strength and elongation increased by 155% and 92%, respectively.
研究领域:
材料科学
·
高分子化学
✓ 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）