International Journal of Polymer Science
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2019
·
IF 1.892
Weiping Du,Guiming Zhang,Song Wang,Lianjiang Tan,Huifang Chen
An optical polythiourethane based on m-xylylene diisocyanate (XDI) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (BES) has been studied. Triethylamine was adopted as a catalyst, and the solid-state isothermal cure reaction was carried out using FTIR spectroscopy, in the temperature range of 75°C-105°C. The -NCO absorption band of XDI was used to monitor the conversion of diisocyanate into polythiourethane. The reaction rate enhanced with an increase in the content of the catalyst, and the gel time determined by swelling test was shorter for the system with higher catalyst content. Kinetic parameters were calculated from the infrared spectrum data, and the results showed that the curing reaction of polythiourethane accords with first-order kinetic characteristics. The activation parameters obtained from the evaluation of kinetic data were , , and . The observed negative entropy of activation value supported the formation of a transition state in the cure reaction.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2017
·
IF 3.743
Sicheng Xing,Ying Song,Juan Boo Liang,Mohammad Faseleh Jahromi,Parisa Shokryazda,Jiandui Mi,Cui Zhu,Jie Wang,Xindi Liao
In vitro Lead (Pb 2+ ) binding capacity of two probiotic bacteria strains, namely Bifidobacterium longum BB79 and Lactobacillus pentosus ITA23, was assessed following incubation with the intestinal contents (IC) of laying hens. Results of this study demonstrated that IC treatment significantly enhanced ( P <0.01) Pb 2+ binding capacity of both bacterial strains. Fourier transform infrared analysis indicated that several functional groups (O-H or N-H, C-H, C˭O, C-O, and C-O-C) on the bacteria cell wall involved in metal ion binding were altered after IC incubation, and new groups appeared between the 3700 cm −1 and 4000 cm −1 bands. Transmission electron microscopy demonstrated that after incubation with IC, unidentified IC components created new binding sites on the bacterial cell surface. These particles also changed the mechanism of Pb 2+ binding of the two strains from intracellular accumulation to extracellular adsorption.
研究领域:
微生物学
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毒理学
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食品科学
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DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2017
·Vol. 19
·期 28
·18556-18564
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IF 4.123
Yalan Dai,Peiyi Wu
A new LCST-type thermoresponsive polyelectrolyte P[P4,4,4,4][SS], poly(tetrabutyl phosphonium styrene sulfonate), was introduced to PMEO2MA (poly(2-(2-methoxyethoxy)ethyl methacrylate)) via RAFT polymerization, in order to explore the transition behavior of the block copolymer PMEO2MA-b-P[P4,4,4,4][SS] with two distinct LCST-type segments. A relatively sharp LCST-type phase transition with only one transition point is observed in the turbidity curves, while the whole phase transition is completely different from the micro perspective. The phase transition temperature range is relatively broad, according to the unsynchronized changes of different protons of the two blocks in the temperature-variable 1H NMR analysis. From PCMW analysis, it is found that there exists an obvious two-step phase transition behavior, especially in the region of the C–H groups. Accordingly, we divided the whole transition process into two subregions: 20–40 °C and 40–55 °C in 2Dcos analysis. At the first stage of 20–40 °C, the CH3 groups mainly belonging to the backbones of PMEO2MA blocks have the earliest response to the heating and drive the first step of the dehydration process of PMEO2MA-b-P[P4,4,4,4][SS], resulting in the formation of an intermediate micelle state composed of the collapsed PMEO2MA core and hydrophilic P[P4,4,4,4][SS] corona. In particular, the conformational changes and the more compact structures due to the interaction between the CO groups and P[P4,4,4,4][SS] segments (ν(CO⋯D2O-PILs)) were observed using IR analysis. With the continual increase of the temperature, when the second temperature range of 40–55 °C is reached, the P[P4,4,4,4][SS] segments start to collapse and expel the water molecules, driven by the anions of the poly(ionic liquid)s, with the phosphonium cations being distributed over the relatively hydrophilic outside.
研究领域:
高分子化学
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物理化学
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DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2017
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IF 3.387
Wenxia Wang,Guohe Huang,Chunjiang An,Xiaying Xin,Yan Zhang,Xia Liu
From the viewpoint of sustainability, biomass adsorbent has a high potential in pollution control and there is an emerging interest to investigate the behaviors of pollutants at the interface between biomass adsorbent and solution. This study investigated the performance of cetyltrimethylammonium bromide surfactant-modified flax shives (MFS) for removal of anionic azo dyes from aqueous solution. The equilibrium and kinetic analysis for the adsorption of Acid Orange 7 (AO-7), Acid Red 18 (AR-18) and Acid Black 1 (AB-1) on MFS were conducted. The surface of MFS was characterized by synchrotron infrared and SEM analysis. The absorbed amount of three anionic azo dyes varied with the change of adsorbent dosage, pH and ionic strength. The adsorption isotherm data well fit to the Langmuir model. The adsorption process followed the pseudo-second-order kinetics and the liquid film diffusion models. Thermodynamic studies indicated that the adsorption of three anionic azo dyes was spontaneous. The adsorption of AR-18 and AB-1 onto MFS was endothermic while the adsorption of AO-7 was exothermic. The results can help better understand the behaviors of organic pollutants at biomass adsorbent-water interface. They also present the potential of using MFS as a suitable adsorbent for the removal of anionic azo dyes from wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
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2020
·Vol. 306
·期 2
·2000581
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IF 3.853
Yingying Feng,Yexiang Cui,Mingjun Zhang,Meiling Li,Haiyan Li
Tung oil is used as a catalyst-free repair agent. Tung oil-loaded polyurethane (PU) microcapsules are prepared by interfacial polymerization in a SiO 2 -stabilized Pickering emulsion system, polyaniline (PANI) is deposited in situ on the PU microcapsule surface, and tung oil-loaded PU/PANI double-layer shell microcapsules are obtained. Synthesized PU/PANI microcapsules showed the characteristic dark-green color of conductive PANI. The average particle size is 31.1 ± 8.1 µm and the core content is 45.1 ± 4.3 wt%. The microcapsules have a good thermal stability, and the chemical structure of the PU/PANI wall and tung oil core is confirmed by Fourier transform infrared analysis. Self-healing anti-corrosion coatings are prepared by adding 10 wt% microcapsules into epoxy resin. The corrosion resistance properties of the self-healing coating are evaluated by immersing scratched coatings in 10 wt% NaCl solution for 15 days. The self-healing coating with 10 wt% tung oil-loaded PU/PANI microcapsules have the best anti-corrosion property, and slight corrosion do not occur until 15 days after immersion in salt solution. The self-healing and anti-corrosion mechanism are revealed. The tung oil core and the PANI wall of microcapsules contributed synergistically to the excellent self-healing and anti-corrosion properties of the coating through the formation of self-healing films and passivation layers.
研究领域:
材料科学
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化学工程
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腐蚀科学
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表面工程
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DOI
高影响因子
ENERGY
·
2023
·
IF 9
Wei Lu,Ao Gao,Yuntao Liang,Zhenglong He,Jinliang Li,Yong Sun,Shuanglin Song,Shaocong Meng
A stable and highly efficient 1, 1, 3, 3, 3-hexamethyldisilazane (HMDS) terminated m-Cresol inhibitor was synthesized based on the protection-deprotection strategy. The inhibitory effect of HMDS terminated m-Cresol inhibitor on spontaneous combustion of lignite was explored through temperature-programmed oxidation tests, in-situ infrared analysis and thermogravimetric analysis. Results show that, the oxidation of active phenolic hydroxyl groups in the m-Cresol inhibitor can be hindered by the protection of HMDS. After encountering coal, the HMDS terminated inhibitor can be gradually deprotected to regenerate the m-Cresol inhibitor that contains massive active phenolic hydroxyl groups, thus improving the chemical inhibition efficiency of coal spontaneous combustion. For the coal sample inhibited with HMDS terminated m-Cresol inhibitor, the initial contents of the active functional groups are lower and more stable during heating, and the inhibition rate reaches 70% at 130 °C. Moreover, the crossing-point temperature rises by 32.4 °C–181.2 °C. The activation energy increases by 11 kJ/mol and 18 kJ/mol at below and above 130 °C respectively. The peak temperature at maximum weight loss rate rises by 65 °C–431.2 °C, and the corresponding residual carbon rate increased by 31.3%–61.6%. The inhibition mechanism of the HMDS terminated m-Cresol inhibitor on coal spontaneous combustion was deduced.
研究领域:
化工工程
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材料科学
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煤化学
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热分析
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产品关联
DOI
高影响因子
Micro & Nano Letters
·
2017
·Vol. 12
·期 9
·693-696
·
IF 0.723
Xianglong Li,Teng Hou,Yishen Lu,Bin Yang
Many research papers have demonstrated that the starch-based fibres showed poor water stability. In this work, it is proven that citric acid can cross-link starch and improve the water stability of centrifugally spun starch-based fibres. The effect of citric acid concentration on fibre morphology and water stability was studied. Fibre morphology was characterised by scanning electron microscopy and optical microscope. Fourier transform infrared analysis was used to investigate structure changes of fibres during cross-linking.
研究领域:
材料科学
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高分子科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 17
·48609
·
IF 2.188
Qiaoran Zhang,Mengmeng Zhang,Huili Shi,Zhiwei Li,Laigui Yu,Xiaohong Li,Zhijun Zhang,Zhishen Wu
Boron nitride nanosheets (BNNSs) were combined with ammonium polyphosphate (APP) and zinc ferrite (ZF) nanoparticle to prepare APP/BNNS/ZF composite aerogels via a freeze-drying method. Then, epoxy resin (EP) was incorporated into the pores of the as-obtained aerogels via a vacuum-assisted infiltration method to afford APP/BNNS/ZF-EP composites with greatly improved fire resistance. The flame-retardant performance of the as-prepared composites was evaluated by cone calorimetry test; and the flame-retardant mechanism of the aerogels was discussed in relation to thermogravimetric-infrared analysis of the pyrolysis products. Findings demonstrate that the APP/BNNS/ZF-EP composite containing 24.0 wt % of the APP/BNNS/ZF aerogel exhibits superior flame-retardant performance; and its peak heat release rate and total heat release are reduced by 86.2 and 86.5% as compared with those of pristine EP. The reason lies in that APP can be decomposed in the early stage of burning to generate phosphoric acid, thereby promoting the formation of char layer; ZF can catalyze the charring process; and BNNS can act as the physical barrier to retard the burning of EP. In addition, the APP10/BNNS1/ZF0.1-EP composite can be endowed with superhydrophobicity via the modification of polydimethylsiloxane and hydrophobic nanosilica, which could contribute to broadening its scope of application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48609. Highlights 1 Flame-retardant APP/BNNS/ZF aerogels were prepared by a freeze-drying method. 2 APP/BNNS/ZF-EP composites were obtained via a vacuum-assisted infiltration method. 3 The pHRR of composites are reduced by 86.2% as compared with that of pristine EP. 4 The EP composites exhibit excellent flame retardancy and superhydrophobicity.
研究领域:
材料科学
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化学工程
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高分子科学
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消防安全
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF FOOD PROPERTIES
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2023
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IF 2.9
Lixia Zan,Chao Wang
This study presents an ecologically conscious methodology for synthesizing tea polypeptides-selenium nanoparticles (TP-SeNPs) exhibiting antioxidant and antibacterial properties, utilizing tea polypeptides (TP). Proteins were extracted from tea leaves using an alkali extraction-acid precipitation method, and response surface methodology (RSM) was employed to optimize the preparation processes for both TP and TP-SeNPs. The TP extract was obtained with the highest TP content of 28.12% at a pH of 6, temperature of 50°C, duration of 3 h, and enzyme concentration of 4%. TP-SeNPs with a minimum particle size of 98 nm were biosynthesized by adding 3% TP at pH 4 and reaction temperature of 55°C for 6 h. The UV spectrum of TP-SeNPs showed an absorption peak at 285 nm. The EDS peak at 1.37 keV confirmed the presence of selenium in TP-SeNPs. Electron microscopy revealed a thin layer coating on the surface of TP-SeNPs. Infrared analysis showed changes in the C=O, NH, and C-N bonds. XRD analysis indicated the formation of a crystalline structure in TP-SeNPs. The absorbance ratio of the peptide selenium nanoparticle colloidal solution remained stable over 7 days at 25°C and 4°C. TP-SeNPs exhibited higher antioxidant activity than SeNPs at high concentrations. TP-SeNPs contain selenium, carbon, oxygen, and nitrogen, and TP plays a role in stabilizing and encapsulating TP-SeNPs. This may involve physical adsorption, covalent interactions, and other unknown interactions, preventing aggregation or degradation. The crystalline structure of TP-SeNPs improves their material properties and enhances their antioxidant and antibacterial abilities.
研究领域:
材料科学
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纳米技术
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生物技术
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环境科学
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产品关联
DOI
高影响因子
GREEN CHEMISTRY
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2025
·
IF 9.2
Junqi Zhang,Jianlong Wen,Zhenwei Liu,Fangwei Ling,Zhengtian Xie,Yijing Nie,Jinrong Wu
Simultaneously enhancing the strength and toughness of elastomers has long been a great challenge. Inspired by the cell-like structures found in nature, this study employs phosphatidylcholine to modulate the polarity of lignin, and thereby lignin forms a self-assembly “cell-like structure” within hydroxylated polyisoprene rubber, developing a green strategy for synthesizing high-performance rubber. The mechanism underlying the self-assembly of lignin structures was elucidated through two-dimensional infrared analysis and molecular simulations. Furthermore, atomic force microscopy force-distance curve analysis revealed that the presence of phosphatidylcholine not only altered the self-assembled structure of lignin but also facilitated the formation of an interfacial layer between lignin and the rubber matrix, thereby enhancing their compatibility. The “cell-like structure” and compatibility transformation enable the formation of lignin-reinforced hydroxylated polyisoprene rubbers with outstanding mechanical properties, achieving a remarkable strength of 26 MPa and great recovery capabilities in the absence of chemical permanent crosslinking. This innovative approach pioneers a novel green pathway for the sustainable production of high-performance rubber materials.
研究领域:
材料科学
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高分子科学
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仿生学
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纳米技术
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 11
·6677-6689
·
IF 4.21
Ren Yuanlin,Liu Yansong,Wang Yang,Guo Xun,Liu Xiaohui
Abstract Lyocell fibers, one of the green and regenerated cellulose fibers, are widely used in the textile fields. However, lyocell fibers are highly flammable which will cause fire accidents. Herein, a novel biomass-based flame retardant derived from vitamin C (VCFR) was designed and synthesized. Then, the lyocell fabrics were finished with VCFR through esterification to fabricate durable flame retardant lyocell fabrics (RF-lyocell). The structure of the different fabrics was characterized by X-ray photoelectron spectroscopy and Fourier transform infrared analysis analysis. The limiting oxygen index value of the FR-lyocell was as high as 39.8%, which still remained 26.4% after 30 washing cycles, indicating excellent flame retardancy and durability. Thermogravimetric-Fourier transform infrared analysis proved that non-combustion compounds, such as CO 2 and water were generated, and provided an obvious flame retardant effect in the gas phase. Cone calorimeter tests showed that the peak of heat release rate and total heat release had a reduction of 89.5% and 54.5%, respectively. These results suggested that VCFR can be used as an effective biomass-based flame retardant for lyocell fabrics. Graphic abstract
研究领域:
纺织科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
Silicon
·
2023
·Vol. 15
·期 10
·4325-4334
·
IF 3.4
Shi Xu,Xu Weibing,Zhou Zhengfa,Ma Haihong,Ren Fengmei
In order to improve the smoke suppression of silicone oil, relatively high nitrogen content silicone oil was synthesized by the reaction of dicyandiamide (DCD) and epoxy-terminated silicone oil (ETSO) and named DCDSO. The molecular structure of DCDSO was characterized by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR). The flame ignition and cone calorimetry test (CCT) were used to investigate the smoke suppression effect of DCDSO. The results showed that the introduction of DCD significantly improved the smoke suppression performance of DCDSO. When the molar ratio of the epoxy group in ETSO and the primary amino group in DCD was 1:1.3, the flame height and the total smoke production were significantly reduced. Thermogravimetric analysis (TGA), thermogravimetric infrared analysis (TG-IR) and thermal field emission scanning electron microscopy (SEM) were used to explore the mechanism of smoke suppression. The mechanism of smoke suppression is that the introduction of DCD reduces the rearrangement decomposition, promotes the free radical oxidation decomposition and the formation of condensed phase, and thus reduces the generation and release of smoke.
研究领域:
材料科学
·
化学工程
·
消防安全
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）