JOURNAL OF PHYSICAL CHEMISTRY B
·
2025
·
IF 2.9
Haiyang Huang,Yong Zhou,Ling Xie,Bing Li,Wenlong Wang,Xinjuan Liu,Yongli Huang,Chang Q. Sun,Biao Wang
Hydrogels are versatile functional materials with applications in biomedical devices, sensors, and energy systems. However, tailoring their mechanical properties remains a critical challenge for expanding their practical utility. Here, the mechanical properties of poly(vinyl alcohol) (PVA) hydrogels prepared via the freeze–thaw method were effectively tailored through the incorporation of various chloride salts. This study reveals the molecular mechanisms by which salt ions influence the water structure, polymer chain interactions, and freezing behavior to modulate hydrogel performance. Using Raman spectroscopy, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR), we elucidate how cation-specific effects alter the crystallinity, cross-linking density, and hydrogen bond network in the hydrogels. Hydrogels containing K+ exhibited superior rigidity and toughness due to enhanced crystallinity and optimized water–polymer interactions, while hydrogels of Mg2+ and Ca2+ had much lower modulus and adhesion strength since the divalent ions reduced freezing points resulting in reduced polymer aggregation. These findings provide a molecular-level understanding of the salting effects on hydrogel properties, offering new insights into designing materials with tunable mechanical performance for diverse applications.
研究领域:
材料科学
·
高分子科学
·
机械工程
·
生物医学工程
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jinshan Xie,Xiaoxiang He,Kexin Liu,Wulong Li,Zhanxiong Li
In this paper, carboxylated cotton fabric (CF-Ph-COOH) were obtained as active substrate by diazonium radical polymerization modification of cotton fibers. Then the MOF fabric composites were prepared by in situ growth of metal zirconium ions (Zr) and organic ligands on the surface of carboxylated cotton fabrics under carboxylic acid modifier. MOF fabric composites with controllable morphologies structures were achieved by regulating organic ligands, reaction time the type and dosage of regulator (formic acid and acetic acid). The prepared acetic acid regulated MOF fabric composites were designated as CF-HAc1-UiO-66, CF-HAc2-UiO-66, CF-HAc1-UiO-66-NH 2 , and CF-HAc2-UiO-66-NH 2 , respectively, and the formic acid regulated as CF-FA-UiO-66 and CF-FA-UiO-66-NH 2 . The fabricated carboxylic acid modulated MOF fabric composites were well characterized using SEM, TGA, XRD, FTIR, and XPS spectra. The adsorption experiment results show that carboxylic acid modulated Zr based MOF fabric composites can serve as adsorbent for effective removal of Cr(VI) from water, in which the CF-FA-UiO-66-NH 2 was prepared under the ratio of ZrCl 4 and BDC-NH 2 is 1.006 and with 5.47 M formic acid regulator exhibits that the optimal adsorption efficiency and the removal efficiency is 79.5 %. In addition, the adsorption of Cr(VI) in water by CFA-UiO-66-NH 2 showed a quasi-secondary kinetic model following the Langmuir adsorption model, showing a a typical of chemisorption. What’s more, the Cr(VI) removal efficiency and saturated adsorption capacity of CF-FA-UiO-66-NH 2 was up to 80 % and 318.85 mg/g, respectively. The prepared CF-FA-UiO-66-NH 2 MOF fabric composite was recyclable for removal of Cr(VI), and could be used as the potential adsorbent membrane for waste water treatment.
研究领域:
材料科学
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环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 22
·5378
·
IF 4.2
Qiaolin Zuo,Zhenzhong Fan,Qingwang Liu,Yuanfeng Fu,Luoqi Cui,Junfeng Yang
Aiming at the problem of excessive swelling of conventional microspheres for oilfield use, a novel amphiphilic polymerizable crosslinker (AE) was synthesized by quaternary ammonium modification of an unstable crosslinker (AE) using acrylamide, 2-acrylamido-2-methylpropanesulfonic acid as the monomers, N,N′-methylene bisacrylamide as the stabilizing crosslinker, ammonium peroxysulfate and sodium bisulfite as the initiator, and water as the solvent by using a reversed microemulsion method. Double-networked nanomicrospheres were prepared. The preparation conditions of the microspheres were optimized by the surface response method, focusing on the effects of the initiator addition and reaction temperature, and total crosslinker addition on the formation of nanomicrospheres. The samples were characterized by FTIR, TGA, laser particle sizer, and SEM to evaluate the retarded expansion performance and the modulation drive performance. The results showed that the optimal conditions for the preparation of microspheres were m(oil phase):m(water phase) = 3:2, stirring speed of 550 r/min, total crosslinking agent dosage of 0.6% (based on the total mass of monomers, hereinafter the same), initiator dosage of 0.30%, reaction temperature of 45 °C, and reaction time of 4 h. Compared with the conventional polymer microsphere PAM, PAE was slow-expanded for 45 d at 60 °C, and the expansion multiplier was about 16 times, with slow-expansion characteristics; the blocking rate of PAE reached 98.3%, the oil repulsion rate was 73.11%, and the increase in the recovery rate could be up to 11.23%. In this paper, a new type of nanomicrosphere material is investigated to realize the efficient implementation of oil field conditioning and driving.
研究领域:
材料科学
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化学工程
·
石油工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 45
·49414
·
IF 2.52
Yuntong Liu,Li Liu,Yongri Liang
In this work, we investigated the microphase separation, mechanical, and dynamic mechanical properties of thermoplastic polyurethane elastomers (TPUs) with one-soft segment (polypropylene glycol, PPG, or hydroxyl-terminated polybutadiene, HTPB) or bi-soft segment (PPG and HTPB) using FTIR, XRD, SAXS and amplitude modulated-frequency modulated viscoelastic mode of AFM (AM-FM mode AFM) methods. The results showed that the microphase separation process of hard and soft segments (HS and SS) in TPU containing PPG and HTPB soft segments (PPG-HTPB-PU) was restricted by randomly alternated bi-soft segments, which results in formation of a low content of irregular-shaped hard domain (HD). In addition, the microphase separation of PPG-HTPB-PU induced a triple-phased structure of HD, HTPB rich phase and mesophase. The mesophase of PPG-HTPB-PU was formed of HS, PPG and HTPB segments which were excluded out of HD and HPTB rich domains during microphase separation process. The damping temperature range (at tan δ greater than 0.3) of PPG-HTPB-PU was from −14.6 to 32.1°C (46.5°C) which was more broad than that of TPU containing HTPB soft segment (HTPB-PU). The broad damping temperature range of PPG-HTPB-PU is mainly attributed to the enhanced energy consumption caused by the frictional motions of mixed segments of mesophase.
研究领域:
材料科学
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高分子科学
·
机械工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2019
·
IF 3.47
Zhi Zheng,Jun Wang,Yi Wei,Xuejun Liu,Fengwen Yu,Jianbing Ji
La-Fe modified Si-MCM-41 (La-Fe/Si-MCM-41) catalysts were prepared by the wet impregnation method and used in catalytic cracking of soybean oil (CCS) for biofuel production. The catalysts were characterized by BET, XRD, XPS, Py-FTIR and CO 2 -TPD. The results showed that the aromatics content increased with the increase in B/L value, while the content of oxygenated compounds decreased, indicating that Brönsted acid sites were the major active sites for deoxygenation and aromatization reactions. Compared with Si-MCM-41, the Brönsted acidity of LFM-6 sharply decreased from 22.49 to 5.86 μmol g −1 . Accordingly, the aromatics content was reduced from 37.51 wt.% to 14.52 wt.% which was lower than the limitation (15 wt.%) according to the global environmental legislation. However, for the LFM-6 catalyst, the excessive loss of Brönsted acid sites and sharp decrease in BET surface area and pore volume led to the decrease in deoxygenation. As a result, the fatty acids content increased from 2.71 wt.% to 16.67 wt.% and the acid value reached 35.20 mgKOH g −1 . When the La-Fe loading increased to 15 wt.%, part of fatty acids were converted into ketones by the active sites on Fe 2 O 3 /La 2 O 3 and strong Lewis acid sites on catalysts. Besides, the new weak Lewis acid and basic sites on Fe 2 O 3 /La 2 O 3 exhibited the synergistic effect on promoting the generation of alkenes. The CaO/LFM-6 composite catalysts prepared by the mechanical mixing of LFM-6 and CaO were used in CCS to reduce the acid value of biofuel. LFM-6-C-3 was proved to be an effective catalyst for CCS to produce biofuel with low aromatics (12.31 wt.%) and fatty acids (2.76 wt.%) content.
研究领域:
催化
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生物燃料
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化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
·
2021
·
IF 3.66
Qiang Chen,Yuqing Ni,Jun Liang,Lei Ni,Juncheng Jiang,Yong Pan,Qingsheng Wang
Esterification reactions between anhydrides and alcohols catalyzed by sulfuric acid have broad applications in the food, cosmetic, and pharmaceutical industries. However, the exothermic behavior cannot be well explained, especially in semibatch reactors with different feeding procedures. In this study, a series of esterification processes in semibatch systems were conducted with a wide range of feeding rates with two different substrates. The structures of initial catalytic substrates were characterized using in situ Fourier Transform Infrared (FTIR) spectroscopy. A total of 11 reaction pathways, including those for the initial activation of substrates and the subsequent reactions of the feeding process, were calculated by the density functional theory (DFT) method. Three possible catalytic cycles of the esterification with specific acid catalysis, protonated intermediate, and protonated intermediate and H 2 O, were established for the semibatch esterification reaction based on calculated results and experimental evidence. Thermal safety parameters such as reaction enthalpy ( Δ H r ), adiabatic temperature rise ( Δ T r , a d ), and maximum temperature of the synthetic reaction (MTSR) were determined based on Wilson equation used to calibrate mixing heat. The results reveal that mixing heat was 2.5 kJ/mol with same mole ratio of n -butanol ( n B) and propionic anhydride (PA). The reactions started by PA are dominant, no matter whether the substrate is n B or PA. The initial reaction rate is restricted by the low concentration of catalyst and active reactant when n B is used as substrate, which lead to significant reactant accumulation with high MTSR of approximately 160 °C. Furthermore, feeding n B into PA allows a controllable increase in the Δ T r , a d realized by changing the feeding rate and limiting the accumulation of reactant.
研究领域:
化学工程
·
物理化学
·
过程安全
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
·
2022
·Vol. 28
·期 4
·719-725
·
IF 2.297
Deling Li,Congcong Luo,Bing Yao,Yue Ding,Jizhen Ren
Lanthanum complex with curcumin (La L 2 )/Ca-Zn composite stabilizer was prepared using La L 2 and Ca-Zn stabilizer, in which Ca-Zn stabilizer was obtained from calcium stearate and zinc stearate at their mass ratio of 5:1. The rheological properties and dynamic thermal stability of polyvinyl chloride (PVC) stabilized by La L 2 /Ca-Zn composite stabilizers were estimated through a torque rheometer. The degraded fragments obtained from the torque experiments were measured by Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV-vis) spectroscopy. La L 2 had an effective synergistic effect with Ca-Zn stabilizer. Compared with La L 2 , La L 2 /Ca-Zn composite stabilizer could more significantly improve the rheological properties and dynamic thermal stability of PVC. An optimal synergistic effect could be observed when the mass ratio of La L 2 with Ca-Zn stabilizer was about 8:2, in which the plasticizing torque and equilibrium torque of PVC was 33.3 N m and 22.5 N m, respectively, and its dynamic thermal stabilizing time was 25.1 min. The possible thermal stability mechanism of La L 2 /Ca-Zn composite stabilizer for PVC was suggested based on the evaluation of FTIR spectroscopy and UV-vis spectroscopy.
研究领域:
材料科学
·
高分子科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Zhong Sun,Yihan Yin,Yupeng An,Chao Deng,Ziyu Wei,Zijiang Jiang,Xixin Duan,Xiaohui Xu,Jing Chen
A cost-efficient and simple method, grafting sodium sulfonate groups (−SO 3 Na) onto carboxymethyl cellulose (CMC), was developed to form hydrogel adsorbents for the removal of poisonous metals including Cu(Ⅱ) and Zn(Ⅱ) from wastewater. In this work, cellulose-based hydrogels (CMC-g-P(AA-co-SS)) were prepared using acrylic acid (AA) and sodium styrene sulfonate (SS). FTIR, XPS , SEM , and EDX were employed to analyze the surface morphology and structure of CMC-g-P(AA-co-SS). The results revealed that the synergistic effect of −SO 3 Na and carboxylate groups (−COO − ) facilitated the adsorption of heavy metals. Moreover, introducing AA and SS enhanced the swelling degree of CMC hydrogels. The results of adsorption experiments showed that high adsorption efficiencies were obtained for Cu(Ⅱ) and Zn(Ⅱ) (200.44 mg/g and 192.28 mg/g, respectively) within 180 min. The adsorption isotherm and kinetics indicated that the monolayer chemical adsorption dominated the process. After 5 cycles, the adsorption activity of CMC-g-P(AA-co-SS) remained high, with the adsorption capacity for Cu(Ⅱ) and Zn(Ⅱ) being 93.3% and 78.3% of the original, respectively. Thus, the CMC-g-P(AA-co-SS) is a promising adsorbent candidate for the removal of poisonous metals from wastewater.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Niu Liu,Jun Cheng,Wen Hou,Xiao Yang,Junhu Zhou
In order to form strengthened active sites for superior CO 2 adsorption on core shell ZIF-8@ZIF-67 nanocomposites , graphene oxide (GO) with oxygen-containing functional groups was used as support to synthesize hybrid adsorbents with unsaturated Zn–N 2 –O active sites. The results of XPS O 1s and FTIR analysis revealed that the Me–O functional group content in the 0.5 wt% graphene oxide (GO)-supported core shell ZIF-8@ZIF-67 nanocomposite (38.9 at.%) was much higher than that in the 0.5 wt% reduced graphene oxide (RGO)-supported nanocomposite (19.4 at.%). This was because hydroxyl functional groups in the GO formed coordination bonds with zinc atoms in core shell ZIF-8@ZIF-67. XPS N 1s spectra indicated that the incorporation of oxygen-containing functional groups in GO resulted in the transition of binding form from Me–N 4 to Me–N 2 . The CO 2 adsorption capacity of GO-supported core shell ZIF-8@ZIF-67 gradually decreased from 2.15 to 1.30 mmol/g as GO weight percentage increased from 0.5 to 4 wt%, which was consistent with the decrease in BET surface area from 1378 to 585 m 2 /g and increase in peak pore diameter from 7.7 to 8.2 Å. Density functional theory (DFT) calculations demonstrated that unsaturated Zn–N 2 –O active sites in GO-supported core shell ZIF-8@ZIF-67 nanocomposites resulted in a decreased O C⋯Zn interaction distance from 4.65 (Zn–N 4 sites in core shell ZIF-8@ZIF-67) to 3.46 Å and an increased binding energy from 34.02 to 38.87 kJ/mol. Therefore, 0.5 wt% GO-supported core shell ZIF-8@ZIF-67 nanocomposites exhibited the highest CO 2 adsorption capacity of 2.15 mmol/g (at 273 K and 1 bar), 1.34 times higher than that of core-shell ZIF-8@ZIF-67.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Leisheng Che,Jinqiu Guo,Zhiwei He,Hongbo Zhang
We report here that the reduction degree of the metal at the catalytic interface dominates the reactivity of acetylene hydrogenation, mainly in terms of turnover rates (TORs) and activation energies, which could certainly cause the switch of kinetically relevant steps (KRS) from “C 2 H 3 *+H*” over Ce(OH)SO 4 ·xH 2 O dispersed Pd catalyst to “C 2 H 4 *+H*” elementary step over Pd/CeO 2 . Besides, a compact kinetic model has been established to describe the reaction process and the dissociative mechanism was confirmed by H 2 /D 2 exchange experiment. Meanwhile, the rate-determining step (RDS) and the main adsorbed species of the reaction were confirmed by systematic kinetic studies as well as in-situ FTIR analysis. More importantly, with the aid of parity fitting and gas isothermic adsorption analysis, the energetic relationship among the steps along with the acetylene hydrogenation is quantitatively described, which provides a good support and complement for the previous research, and helps researchers build up advanced reaction systems.
研究领域:
化学动力学
·
催化
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Yanan Yang,Yu Zhang,Hong Zheng,Baichao Zhang,Qi Zuo,Kaiyue Fan
A key challenge in trace heavy metals removal from drinking water by adsorption technology is to achieve high adsorption capacity and rapid uptake speed of adsorbent. Herein, we report a functionalized double modified covalent organic framework (DMTD–COF–SH) bearing high-density sulfur and nitrogen chelating groups provided simultaneously by 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and 1,2-ethanedithiol, which was prepared via a facile one-pot thiol-ene “click” reaction. PXRD , FTIR, XPS, SEM, BET and 13 C MAS NMR confirmed their successful graft, and DMTD was found to be more easily grafted on the COF surface layer than 1,2-ethanedithiol. The as-prepared DMTD–COF–SH showed remarkable adsorption capacity and ultrafast uptake dynamics to trace heavy metals owing to the synergistic effects resulting from densely populated sulfur and nitrogen chelating groups within ordered COF mesopores and at the COF surface. On the basis of the drinking water treatment units standard NSF/ANSI 53–2020, when the adsorbent dosage was 10 mg/30 mL and 20 mg L −1 calcium ions coexisted, the lead concentration decreased from initial 150 μg L −1 to 2.89 μg L −1 within 10 s, far below the allowable limit of world health organization (WHO) drinking water standard (10 μg L −1 ), and the maximum adsorption capacity meeting the standard attained 14.22 mg g −1 . The adsorbent also exhibited excellent stability, wide applicable pH range and outstanding adsorption performance for coexisting trace lead, mercury, cadmium, chromium (VI) and copper in tap water, indicating that the DMTD–COF–SH material has excellent application prospect for trace heavy metals removal from drinking water.
研究领域:
环境科学
·
材料科学
·
水处理
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Hengli Qian,Guanjie Yu,Qidong Hou,Yifan Nie,Chuanyunlong Bai,Xinyu Bai,Haozhi Wang,Meiting Ju
To achieve efficient degradation of pharmaceutical and personal care products (PPCPs), dual reaction centers [email protected] photo-Fenton catalysts with high-speed electron transmission channel were designed through surface hydroxyl-induced assembly. In [email protected] catalytic system, the photocatalysis center of ZnO and Fenton catalytic center of FePc were formed simultaneously. Concept and process for the control of hydroxyl groups to construct a dual reaction center [email protected] photo-Fenton catalyst were verified ingeniously based on the density functional theory (DFT) analysis and experimental results. A series of catalysts, including ZIF-8 (400 ℃-N 2 ), FePc (400 ℃-N 2 ), ZIF-8 (400 ℃)-FePc (400 ℃) and [email protected] were prepared and characterized by XRD, FTIR, TEM, BET, XPS, PL and DRS, respectively. The [email protected] catalyst showed superior performance for the photo-Fenton degradation of ibuprofen, affording degradation rate larger than 90 % within just 10 min under simulateed sunlight. The excellent performance of [email protected] catalyst is mainly attributed to the synergistic effect between dual reaction centers of [email protected] This work provides a novel method to construct dual reaction centers [email protected] catalyst with efficient photo-generated electrons transmission link and to strengthen the synergistic effect of dual reaction centers.
研究领域:
环境化学
·
催化
·
材料科学
·
光化学
✓ 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）