MACROMOLECULES
·
2021
·
IF 5.985
Noy Cohen,Cong Du,Zi Liang Wu
The submersion of a polymer network with a high density of hydrogen bond based cross-links in an aqueous bath results in the formation of a rubberlike hydrogel. The cross-links, which connect chains and maintain the structure of the network, can dissociate as a result of two main factors: (1) the interactions between the hydrogen bonds and the surrounding water molecules and (2) the forces that are exerted on the cross-link from the interconnected chains. We recall that these forces depend on the ratio between the end-to-end distance and the overall contour length of the chains. The application of an external loading translates into the stretching of chains in the network and, as a consequence, an increase in the forces that are exerted. Sufficiently large external loadings can break cross-links and alter the microstructure of the network. From a macroscopic viewpoint, the breaking of cross-links leads to significant microstructural changes such as a reduction in the chain density and an entropic gain. In this work, we derive a microscopically motivated and energy-based model that captures the effects of hydration and external loadings on the overall changes in properties and mechanical response of hydrogels. We provide a systematic method to estimate the percentage of cross-links that dissociate due to hydration and application of a force and provide representative examples to highlight the influence of the orientations of the interconnected chains with respect to a cross-link. To validate the model, we carry out uniaxial tension experiments on poly(methacrylic acid) hydrogels with five different water contents and fit the model parameters. We show that the model is capable of qualitatively and quantitatively capturing the experimental results. The model is also used to approximate the number of cross-links that dissociate due to the water and the externally applied uniaxial force. This work paves the way to the efficient design of multifunctional synthetic hydrogels with programmable properties and behaviors.
研究领域:
材料科学
·
生物工程
✓ 已验证
产品关联
DOI
高影响因子
Advanced Science
·
2021
·Vol. 8
·期 15
·2100402
·
IF 16.806
Wei-Pin Huang,Hong-Lin Qian,Jing Wang,Ke-Feng Ren,Jian Ji
Periodic porous structures have been introduced into functional films to meet the requirements of various applications. Though many approaches have been developed to generate desired structures in polymeric films, few of them can effectively and dynamically achieve periodic porous structures. Here, a facile way is proposed to introduce periodic stratified porous structures into polyelectrolyte films. A photo-crosslinkable polyelectrolyte film of poly(ethylenimine) (PEI) and photoreactive poly(acrylic acid) derivative (PAA-N 3 ) is prepared by layer-by-layer (LbL) self-assembly. Stratified crosslinking of the PEI/PAA-N 3 film is generated basing on standing-wave optics. The periodic stratified porous structure is constructed by forming pores in noncrosslinked regions in the film. Thanks to the dynamic mobility of polyelectrolytes, this structural controlment can be repeated several times. The size of pores corresponding to the layer spacing of the film contributes to the structural colors. Furthermore, structural color patterns are fabricated in the film by selective photo-crosslinking using photomasks. Although the large-scale structural controlment in thick (micron-scale and above) films needs to be explored further, this work highlights the periodic structural controlment in polymeric films and thus presents an approach for application potentials in sensor, detection, and ink-free printing.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOID AND POLYMER SCIENCE
·
2020
·Vol. 298
·期 4
·495-504
·
IF 1.536
Zhang Xuechun,Cao Yongbin,Jiang Qin,Zhang Yuanying,Yang Wuli
Cross-linked poly(methyl methacrylate) (PMMA) microspheres have been successfully prepared by using the asymmetric cross-linker allyl methacrylate (AMA) via dispersion polymerization. The influence of the AMA amount and polymerization process on the PMMA particle size and morphology has been studied thoroughly. It was found that micron-sized, cross-linked PMMA particles with narrow size distributions could be obtained by a semi-continuous process with the asymmetric cross-linker AMA. The obtained micron-sized, cross-linked PMMA particles could be further used as a light diffusion agent in a polycarbonate matrix, and their light diffusion properties were significantly enhanced by increasing the gel content in the cross-linked particles. Moreover, the influence of the polymerization process, cross-linker content in PMMA and PMMA content in the polycarbonate matrix on light diffusion was carefully investigated. The results showed that the PMMA particles containing 5.0 wt% AMA, obtained by semi-continuous polymerization, had a higher haze and gel content and exhibited a better light diffusion effect than did the other particles.
We prepared cross-linked PMMA microspheres by dispersion polymerization with asymmetric cross-linker AMA and obtained light diffusers by blending cross-linked PMMA microspheres with matrix PC.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2015
·
IF 3.562
Liangxiao Tan,Buyi Li,Xinjia Yang,Weixing Wang,Bien Tan
A new series of hypercrosslinked polymers were efficiently synthesized by knitting rigid aromatic building blocks using a novel external crosslinker (1,4-dimethoxybenzene, DMB) which result in a conjugated microporous structure. This knitting hypercrosslinked conjugated microporous polymers (HCCMPs) are predominantly microporous and exhibit high surface area of up to 800 m 2 g −1 , which also show comparable gas uptake properties reaching 1.14 wt. % H 2 adsorption at 1.13 bar/77 K, and 12.72 wt. % CO 2 adsorption at 1.13 bar/273 K, respectively. The extended π-conjugated structure and the three-dimensional network of π–π stacked aryl rings enable these HCCMPs good luminescence properties and high electrical conductivity .
研究领域:
高分子化学
·
材料科学
·
纳米多孔材料
·
物理化学
·
能源材料
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Yinchuan Pu,Duoduo Huang,Su Wang,Wei Xu
Developing robust and durable superhydrophilic surfaces on polyethylene terephthalate (PET) films is critical for advancing their applications in self-cleaning and biomedical technologies. In this study, a coating solution containing polyethyleneimine and HDI polyisocyanate was bar-coated onto PET film surfaces and subsequently cross-linked to form a dense R-NH-CO-NH-R' covalent network. After modification, the PET film surfaces demonstrated superhydrophilicity (WCA=0°) accompanied by a significant increase in surface energy to 79.4 mN/m, while achieving excellent 5B-grade adhesion. Furthermore, when exposed to 40-hour immersion in aqueous solutions, the modified surfaces maintained their superhydrophilicity (0° WCA) with essentially unchanged surface energies. The coatings showed near-complete surface coverage along with substantial covalent bonds retention. Such crosslinking construction approach via bar-coating exhibits promising potential for PET films in superhydrophilic applications.
研究领域:
生物医学工程
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材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 32
·期 39
·2204823
·
IF 19.924
Wei Cui,Yong Zheng,Ruijie Zhu,Qifeng Mu,Xiaoyu Wang,Zhisen Wang,Shengqu Liu,Min Li,Rong Ran
Ion is one of the most common additives that can impart electrical conductivity to insulating hydrogels. The concurrent toughening effect of ions, however, is often neglected. This work reports the extreme toughening of hydrogels via the synergistic effect of cations and anions, without the need for specific structure design or adding other reinforcements. The strategy is to equilibrate a physical double network hydrogel consisting of both multivalent cation- and kosmotropic anion-sensitive polymers in specific salt solutions that can induce cross-linking and salting-out simultaneously. Both effects are proven positive to boost the mechanical performance and electrical conductivity of the original weak gel, and result in a tough conductive gel with exceptional physical properties, achieving significant enhancements in fracture stress, fracture energy, and ionic conductivity by up to 530-, 1100-, and 4.9-folds, respectively. The optimal fracture stress and toughness reach approximately 15 MPa and 39 kJ m –2 , exceeding most state-of-the-art tough conductive hydrogels. Meanwhile, a satisfactory ionic conductivity of 1.5 S m –1 is attained. The presented simple strategy is also found generalizable to other salt ions and polymers, which is expected to expand the applicability of hydrogels to conditions involving demanding mechanical durability.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
·
2020
·
IF 1.529
Bin Wang,Chong Lu,Jing Hu,Weixin Lu
Ethylene vinyl alcohol (EVOH) with excellent barrier properties has insufficient thermomechanical properties. The introduction of magnesium chloride (MgCl2) as an initiator in EVOH blends improved its properties by cross-linking. Torque behavior and gel experiment analysis indicated that a cross-linking in EVOH was formed. The cross-linking mechanism was confirmed through 13C nuclear magnetic resonance spectroscopy (13C NMR) and Fourier-transform infrared (FTIR) spectrometry. In 13C NMR spectra, the splitting peaks of CH carbon and CH2 carbon tended to disappear, and the stretching vibration peak of –C=C– was observed in the FTIR spectra. The formation of hydrogen bond between MgCl2 and EVOH destroyed the intramolecular and intermolecular hydrogen bonds of EVOH, which contributed to the dehydration of –OH to form –C=C–, and –C=C– was the basis for a cross-linking reaction. The thermal analysis of blends demonstrated that the melting temperature and crystallization temperature decreased, and the crystallinity gradually disappeared when the MgCl2 content increased. Glass transition temperature significantly increased as the intermolecular force enhanced. Thermogravimetric analysis showed that a cross-linked structure could improve the thermostability of EVOH with an increase in the MgCl2 content. Mechanical test results revealed a remarkable increase in the tensile strength of EVOH as the MgCl2 content increased.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 20
·3489
·
IF 4.329
Yashu He,Jingting Wang,Igor S. Sirotin,Vyacheslav V. Kireev,Jianxin Mu
This study reports on a series of crosslinked poly(arylene ether)s with POSS in the main chain. The fluorinated and terminated poly(arylene ether)s were first synthesized by the nucleophilic reaction of diphenol POSS and decafluorodiphenyl monomers, including decafluorobiphenyl, decaflurobenzophenone, and decafluorodiphenyl sulfone. They were then reacted with 3-hydroxyphenyl acetylene to produce phenylacetylene-terminated poly(arylene ether)s. The polymers were of excellent processability. When heated to a high temperature, the polymers converted into a crosslinked network, exhibiting a low range of dielectric constant from 2.17 to 2.58 at 1 HMz, strong resistance against chemical solutions, low dielectric losses, and good thermal and hydrophobic properties.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Advanced Science
·
2024
·
IF 14.3
Wen Zhou,Yuwan Chen,Wenxin Fu,Xinwei Li,Yufei Xia,Qun Zhao,Baofeng Zhao,Yukui Zhang,Kaiguang Yang,Lihua Zhang
The study of in situ conformations and interactions of mitochondrial proteins plays a crucial role in understanding their biological functions. Current chemical cross-linking mass spectrometry (CX-MS) has difficulty in achieving in-depth analysis of mitochondrial proteins for cells without genetic modification. Herein, this work develops the reactive oxygen species (ROS)-responsive cross-linker delivery nanoparticles (R-CDNP) targeting mitochondria. R-CDNP contains mitochondria-targeting module triphenylphosphine, ROS-responsive module thioketal, loading module poly(lactic-co-glycolic acid) (PLGA), and polyethylene glycol (PEG), and cross-linker module disuccinimidyl suberate (DSS). After targeting mitochondria, ROS-triggered cross-linker release improves the cross-linking coverage of mitochondria in situ. In total, this work identifies 2103 cross-linked sites of 572 mitochondrial proteins in HepG2 cells. 1718 intra-links reveal dynamic conformations involving chaperones with ATP-dependent conformation cycles, and 385 inter-links reveal dynamic interactions involving OXPHOS complexes and 27 pairs of possible potential interactions. These results signify that R-CDNP can achieve dynamic conformation and interaction analysis of mitochondrial proteins in living cells, thereby contributing to a better understanding of their biological functions.
研究领域:
生物化学
·
细胞生物学
·
分子生物学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2010
·Vol. 1
·期 10
·1638-1643
·
IF 0
Yin Wang,Guohua Jiang,Xinke Sun,Miaojun Ding,Hongyuan Hu,Wenxing Chen
Shell cross-linked polymeric nanoparticles were prepared through an interfacially confined copolymerization of styrene and disulfide cross-linker in a reversible addition-fragmentation chain transfer (RAFT) miniemulsion system using poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA) as stabilizer and macroinitiator. 1H NMR, FT-IR, and FE-SEM have been applied to investigate the structures and morphologies of the resultant nanoparticles. Fluorescent spectra results show that the as-prepared samples have fluorescent properties, which may be used as a fluorescent carrier for control release of guest molecules.
研究领域:
高分子化学
·
纳米医学
·
药物递送
·
生物材料
·
聚合物科学
✓ 已验证
DOI
Soft Matter
·
2012
·Vol. 8
·期 21
·5888-5895
·
IF 4.39
Zhaoxing Liu,Yaodong Xu,Lei Cao,Chunyan Bao,Huanghui Sun,Lei Wang,Kerong Dai,Linyong Zhu
Biodegradable and biocompatible elastomer polymers have significant potential in biotechnology and bioengineering. In this paper, we designed, synthesized, and characterized a series of biodegradable and biocompatible elastomers based on phosphoester cross-linked vegetable oils (PVOs), which were prepared by simple cross-linking reactions between phosphorylated castor oil (PCO) and epoxidized vegetable oils (EVOs), epoxidized soybean oil (ESO) and epoxidized linseed oil (ELO), without any solvent or initiator, at 37 °C. The ratios between PCO and the EVOs, and the functionality of the EVOs, play a role in the properties of the elastomer polymers, such as their mechanical properties and degradation. Moreover, the elastomer polymers can be degraded completely on account of the fracture of the phosphoester and triglyceride. The elastic evaluation tests show that PVOs meet the demand for elastomers that can deform and return to their original dimensions even after 1000 repeats of the cyclic compression test. Cytotoxicity studies in vitro indicate that the elastomer polymers and their corresponding degradation products are compatible with the L929 cell line. And the implantation test for the elastomer polymers in animal skin shows that this kind of elastomer can be absorbed completely within 3 months, accompanying the restoration of the implantation sites to their normal architecture.
研究领域:
生物材料学
·
高分子科学
·
组织工程
·
再生医学
·
生物医学工程
·
药物递送
·
生物降解
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2021
·
IF 5.03
Qingkun Liu,Jia Li,Yunchao Jiang,Chuanbo Cong,Lixin Xu,Ying Zhang,Xiaoyu Meng,Qiong Zhou
The degradation of peroxide-cured EPDM and sulfur-cured EPDM in an acid solution (12.5 ppm H 2 SO 4 +1.8 ppm HF) was investigated, and it was found that the degradation of the two in an acid solution was different. The degradation degree of the sulfur curing system is lower than that of the peroxide curing system. During the aging process, the molecular main chain of the peroxide-cured EPDM was broken, resulting in a double bond and C=O structure. When there is a coagent TAIC in the peroxide curing system, the presence of TAIC delays the degradation time of the EPDM molecular backbone, and the hydrolysis reaction of the TAIC crosslinking point occurs preferentially, which makes the stability of EPDM improved. In addition, regardless of the presence or absence of TAIC, the peroxide-cured EPDM undergoes a crosslinking reaction in the later stage of aging, resulting in an ether-crosslinked structure, thereby improving the damaged crosslinking network. Unlike the degradation of the peroxide curing system, the breakage of the molecular backbone does not occur in the sulfur-cured EPDM, but only an internal crosslinking reaction of the curing precursor occurs, resulting in a crosslinked network dominated by polysulfide bonds, thereby increasing the crosslinking density of the EPDM during the aging process.
研究领域:
材料科学
·
高分子化学
·
环境化学
✓ 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）