SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
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IF 5.107
Haoze Zeng,Yanbo Li,Cunwen Wang
SPEEK (sulfonated poly ether ether keton) is a type of very attractive polymeric material in membrane applications. Properties of SPEEK membranes can be tailored through controlling its sulfonation degree. However, the sulfonation degree affects the mechanical strength and membrane stability. SPEEK/PES composite membranes were prepared via a surface coating method. Those membranes show lower retentions due to the swelling of SPEEK. ZIF-8, constructed from zinc centers and 2-methlimidazole ligands, was incorporated into SPEEK to improve their performance. Sulfonation groups in SPEEK closely link to ZIF-8 through the coordination and electrostatic interactions, proved by ATR-IR characterizations and IEC measurements. The ionic crosslinked ZIF-8-SPEEK composite membranes show a higher desulfonation temperature and a lower swelling, evidenced by the TGA results and the water uptake values of ZIF-8-SPEEK composites. The crossflow filtrations show the ionic crosslinked ZIF-8-SPEEK composite membranes have good retentions of PEG1000 (70–90%), dyes (>90%) and salts (30–40%). The membrane retentions increase, whereas the permeances decrease after filling of ZIF-8. More than 100 h filtrations indicate that those membranes have a good stability. Although ZIF-8 particles are believed providing extra permeating channels, the strong ionic interactions have a domain effect on the membrane permeance.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 11
·1557
·
IF 4.7
An Wei,Shunxiang Wang,Yongjin Zou,Cuili Xiang,Fen Xu,Lixian Sun
To broaden the applications of wood, it is necessary to prepare flame-retardant coatings that can protect wood substrates during combustion. In this study, a bio-based, intumescent, flame-retardant phytic acid–melamine polyelectrolyte (PM) was prepared using phosphorus-rich biomass phytic acid and nitrogen-rich melamine as raw materials through an ion crosslinking reaction. Subsequently, a series of bio-based, flame-retardant wood coatings were prepared by optimizing the structure of urea–formaldehyde resin with the addition of melamine, sodium lignosulfonate, and PM as a flame-retardant curing agent. Woods coated with PM-containing coatings displayed significantly improved flame-retardant performances in comparison to uncoated woods. For PM-cured woods, the measured values of total heat release and total smoke production were 91.51% and 57.80% lower, respectively, compared with those of uncoated wood. Furthermore, the fire growth index decreased by 97.32%, indicating a lower fire hazard. This increase in flame retardancy and smoke suppression performance is due to the dense expanded carbon layer formed during the combustion of the coating, which isolates oxygen and heat. In addition, the mechanical properties of the flame-retardant coatings cured with PM are similar to those cured with a commercial curing agent, NH4Cl. In addition, the prepared flame-retardant coating can also stain the wood. This study proves the excellent flame-retarding and curing effect of ammonium phytate in urea–formaldehyde resin coatings and provides a new approach for the application of bio-based flame retardants in wood coatings.
研究领域:
材料科学
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林业工程
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生物质化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 21
·16597-16606
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IF 4.6
Xiaojing Chen,Jia Li,Caojie Zhao,Wen Zhou,Jin Yang,Qingjun Liu,Wenshuai Jiang
Ion cross-linking is often used to prepare graphene hydrogels, but the effects of different ion introductions on the properties of graphene hydrogels need to be further explored. In this study, graphene oxide (GO) and GO@MXene non-spherical hydrogels were prepared by introducing different ions, and their adsorption effects on methylene blue (MB) were discussed to determine their feasibility in water treatment. The adsorption efficiencies were significantly variable because the introduction of different ions had different effects on the internal structure and molding process of the hydrogels. The GO and GO@MXene hydrogels crosslinked with Ca2+ demonstrated superior MB adsorption performance compared to those prepared with K+ and Al3+, achieving 85.2% and 85.8% MB removal efficiencies within 9 hours, respectively. Interestingly, the morphology of the hydrogel can be changed by adjusting the drop height, which in turn affects the MB adsorption. The results showed that hydrogels had faster MB removal by preparing them from a higher height (3.5 cm). The results demonstrated that hydrogels prepared from a higher droplet fall height (3.5 cm) exhibited accelerated MB removal, with a 10–20% enhancement in removal efficiency. In addition, the effects of pH and contact time on the adsorption performance of the hydrogels were investigated. The results showed that the best removal effect was achieved under neutral conditions, and the adsorption process was consistent with the pseudo-quadratic kinetic model (R2 > 0.97). In addition, we found that the introduction of MXene enhanced the water stability of the hydrogels, which increased with the metal ion valence number. Furthermore, our study demonstrated that Ca2+-crosslinked GO and GO@MXene hydrogels exhibit excellent selective adsorption of cationic dyes, achieving MB removal efficiencies of 96.6% and 98.3% in mixed dye systems, respectively. This study not only confirms that the introduction of ions can affect the properties of hydrogels by modulating their morphology, but also provides potential candidates for MB adsorption.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2022
·
IF 6.267
Xuefeng Zhang,Huanbo Wang,Zhijun Chen,Shiyu Guo,Yuan Fu,Tian Liu
Fast-growing natural poplar wood is not meet with in many requirements such as high strength and flame retardant due to its porous structure and loose materials. In this study, we established a simple and feasible method that includes delignification, ionic bond formation via the crosslinking of carboxyl groups in TEMPO-oxidized wood after delignification with calcium ions , and hot-pressing of stacked veneers to improve the quality, density, strength, toughness, and weather resistance of natural wood (NW). This method has the following advantages: The inner cellulose microfiber is highly aligned, thus closely cross-linking and tightly bonding cellulose microfibers and nanofibers between the interfaces and inner layers of the wood boards via hydrogen bonding and ionic bonding. A laminated densified TEMPO-oxidized ionic wood (IW) showed substantially higher specific strength (∼196.9 MPa cm3 g−1), higher tensile strength (∼246 MPa), higher flexural strength (∼257 MPa), higher flexural modulus (∼36 GPa), higher impact toughness (∼42.34 kJ m−2), and superior fire retardancy, UV resistance, water resistance, and also higher density (∼1.25 g cm−3) than NW. Larger-size laminated densified structural materials with satisfactory thermal stability can also be fabricated using the proposed method.
研究领域:
材料科学
·
林业工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
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IF 8.097
Xuefeng Li,Hui Wang,Dapeng Li,Shijun Long,Gaowen Zhang,ZiLiang Wu
We report a dual ionic cross-linking approach for the preparation of double-network hydrogels with robustness, high strength, and toughness, sodium alginate/poly(acrylamide-co-acrylic acid)/Fe3+ (SA/P(AAm-co-AAc)/Fe3+), in a facile “one-step” dual ionic cross-linking method. We take advantage of the abundant carboxyl groups on alginate molecules and the copolymer chains and their high coordination capacity with multivalent metal ions to obtain hydrogels with high strength and toughness. The optimal SA/P(AAm-co-AAc)/Fe3+ (SA 2 wt % and AAc 5 mol %) hydrogels showed a remarkable mechanical performance with 3.24 MPa tensile strength and 1228% strain, both of which remained stable with 76% water content and were highly swelling resistant in an aqueous environment. The hydrogels possessed high fatigue resistance, self-recovery, pH-triggered healing capability, shape memory, and reversible gel–sol transition facilitated by pH regulation. Moreover, they show three-dimensional (3D) printing processability by properly adjusting the solution viscosity. The approach may provide a convenient way of obtaining hydrogels having high strength and toughness with a number of desirable properties for a broad range of biomedical applications.
研究领域:
材料科学
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生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
Polymers
·
2021
·Vol. 13
·期 5
·742
·
IF 4.329
Wanyu Chen,Siyuan Liu,Le Guo,Guixia Zhang,Heng Zhang,Meng Cao,Lili Wu,Tianxing Xiang,Yong Peng
An ionic liquid-based ionically cross-linked gel polymer electrolyte (GPE-ILs) was successfully synthesized using acrylic acid, 2-diethylaminoethyl methacrylate, methyl methacrylate, and ionic liquids. Electrochromic devices (ECDs) with an architecture of glass/FTO/WO3/GPE-ILs/FTO/glass were fabricated by a laminating technology. The devices showed performances of large optical modulation of 49.9% at 650 nm, short switching times with the coloration time (tc) of 7 s and the bleaching time (tb) of 4 s, high coloration efficiency of 96.2 cm2C−1, and cycling stability of 200 cycles. The GPE-ILs exhibits high ionic conductivity, superior thermal stability and good self-healing ability. GPE-ILs demonstrates an ionic conductivity of 3.19 × 10−3S cm−1at 25 °C and the same ions migration behaviors with most widely used liquid electrolyte between −10 and 80 °C maintains more than 80% of its tensile strength after self-healing and received only 5% weight loss at 300 °C.Keywords:electrochromic device;ionically cross-linked gel;electrolyte;ionic liquids
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2016
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IF 1.112
Liqiang Zhu,Chuanzhuang Zhao,Dirong Gong
As an ionic cross-linker that can change the size of poly(N-isopropylacrylamide-co-acrylic acid) microgel, Ca2+ is applied as a trigger to demulsify microgel-stabilized oil/water Pickering emulsions. The influence of Ca2+ induced intra-particle ionic cross-linking and inter-particle aggregation on the stability of microgel-stablized “Pickering” emulsion is described. At low and mediate concentration of Ca2+, ionic cross-linking can change the internal elasticity of the microgel, and cause the coarsening of the oil droplets. At high concentration of Ca2+, microgels flocculate due to the salt out effect and the emulsion is destabilized. This work provide a facile method to control the stability of the Pickering emulsions at ambient condition.
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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Yongzhi Liang,Yuexin Shen,Xingyue Sun,Haiyi Liang
As a kind of promising material for flexible wearable electronics, conductive hydrogels have attracted extensive interests of researchers for their inherent merits such as superior mechanical properties, biocompatibility, and permeability. Herein, we constructed a new type of highly stretchable, anti-freezing, self-healable, and conductive hydrogel based on chitosan/polyacrylic acid. The large amount of ions inside the network had five functions for the proposed hydrogel, including excellent mechanical behaviors, high conductivity, self-recovery, self-healing and anti-freezing capability. Consequently, the proposed hydrogel possessed tunable stretchability (1190–1550%), tensile strength (0.96–2.56 MPa), toughness (5.7–14.7 MJ/m 3 ), superior self-healing property (self-healing efficiency up to 83.7%), high conductivity (4.58–5.76 S/m), and excellent anti-freezing capability. To our knowledge, the self-healable hydrogel with balanced tensile strength, toughness, conductivity, and low-temperature tolerance can hardly be achieved till now. Furthermore, the conductive hydrogels exhibited high sensitivity (gauge factor up to 10.8) in a broad strain window (0–1000%) and could detect the conventional motion signals of human body such as bending of a knuckle, swallowing, and pressure signal at both room temperature and −20 °C. Moreover, the hydrogels could also be fabricated as flexible detectors to identify different temperatures, different kinds of solutions, and different concentrations of the solution.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yiyang Zhou,Xue Wang,Xiangyu Lin,Zhuomin Wang,Zhen Huang,Lizhen Guo,Hui Xie,Xu Xu,Fuhao Dong
The mechanical properties of ionic conductive hydrogels (ICHs) are generally inadequate, leading to their susceptibility to breakage under external forces and consequently resulting in the failure of flexible electronic devices. In this work, a simple and convenient strategy was proposed based on the synergistic effect of ion cross-linking and salting out, in which the hydrogels consisting of polyvinyl alcohol (PVA) and xanthan gum (XG) were immersed in zinc sulfate (ZnSO 4 ) solution to obtain ICHs with exceptional mechanical properties. The salt-out effects between PVA chains and SO 4 2− ions along with the cross-linked network of XG chains and Zn 2+ ions contribute to the desirable mechanical properties of ICHs. Notably, the mechanical properties of ICHs can be adjusted by changing the concentration of ZnSO 4 solution. Consequently, the optimum fracture stress and the fracture energy can reach 3.38 MPa and 12.13 KJ m −2 , respectively. Moreover, the ICHs demonstrated a favorable sensitivity (up to 2.05) when utilized as a strain sensor, exhibiting an accurate detection of human body movements across various amplitudes.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2025
·
IF 4.3
Yunlong Chen,Jinliang Li,Liman Liu,Yi Li
Coal seam mining generates significant dust, posing serious threats to the safety of mining and the well-being of miners. This study suggests a delayed cross-linking approach to convert the dust suppressant into a gel within the coal seam, introduces a controllable slow-release ionic cross-linking dust suppressant, investigates its seepage behavior, and evaluates its dust suppression effectiveness in a coal seam. The experimental results show that the dust suppressant exhibits low viscosity and high fluidity during injection into the coal seam, facilitating effective infiltration into the seam. By managing the release rate of Ca2+ in the slow-release system, the gelation time of the dust suppressant within the coal seam can be controlled efficiently. While reducing the viscosity, increasing injection pressure promotes material seepage in the coal seam. The optimized injection pressure for the dust suppressant is 7 MPa, and its seepage behavior in the coal seam postinjection resembles that of water. The dust suppressant cross-links and reacts to form a macromolecular mesh structure in tiny internal pores and on the coal seam surface, enhancing the water retention and toughness of the coal seam. These combined mechanisms effectively reduce dust production during coal seam mining, achieving a source reduction of dust production.
研究领域:
采矿工程
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2023
·
IF 5
Sijia Chen,Junyi Tang,Jiachun Feng
The development of high-performance hydrogels has received much attention, but the simple and cost-effective preparation of hydrogels with high mechanical strength and excellent swelling resistance remains a challenge. In this study, a facile and green strategy was proposed to construct a polyvinyl alcohol/chitosan-based (PVA/CS-based) hydrogel with high mechanical strength and superior swelling resistance. By introducing tannic acid (TA), a natural polyphenol, and forming hydrogen bonding cross-linking with the polymer chains through solvent regulation, as well as by ionic cross-linking and salting-out effects further induced through sodium citrate solution immersion, a strong and homogeneous multiple physical cross-linking network was formed, which endowed the resulting hydrogel with excellent mechanical and swelling resistance performance. For the hydrogel with PVA, CS, and TA in the mass ratio of 5:1:5, the tensile strength was up to 8.22 MPa, and the tensile strength retention was up to 96% of the original value after swelling equilibrium. In addition, our hydrogel can be attached in situ to various substrates and enabled wet adhesion. The easy scale-up and energy-saving features made our method highly promising for the preparation of high-performance hydrogels for many advanced applications.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Jinfeng Cao,Yang Wang,Chen He,Yanhui Kang,Jinping Zhou
A dual physically crosslinking (DPC) strategy is used to construct hydrogels with ultrahigh strength. First, polyelectrolyte complex (PEC) hydrogels were prepared through in situ polymerization of acrylic acid monomers in chitosan solutions. Subsequently, cations and anions were introduced into the PEC hydrogels to form strong electrostatic interactions with the polymer chains. The mechanical properties of the DPC hydrogels strongly depended on the ionic concentration and the valence state of the loading ions. The tensile strength of DPC-Na 8-20-2.0, DPC-Mg 8-20-2.0, DPCAl 8-20-2.0 and DPC-Sul 8-20-0.8 reached to 2.36, 12.59, 65.1 and 2.80 MPa, respectively, which were significantly higher than that of PEC 8-20 (0.29 MPa). Moreover, DPC-Na, DPC-Mg and DPC-Sul still maintained a good flexibility. Specifically, hydrogels of DPC-Ca exhibited ionic conductivity and freeze tolerance, which could be cooled to −20 °C without freezing. The DPC strategy opens an avenue to fabricate hydrogels with outstanding mechanical properties.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）