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
JOURNAL OF CHEMICAL PHYSICS
·
2024
·Vol. 160
·期 19
·
IF 3.1
Yan Yuyue,Chen Ligang,Zhang Jiaqi,Ren Guanhua,Zhou Lu,Liu Liyuan,Zhang Xueqian,Ouyang Chunmei,Wang Huabin,Han Jiaguang
Ion hydration plays a crucial role in numerous fundamental processes. Various spectroscopic methods are employed to investigate the slowing down of hydration bond dynamics in the proximity of both anions and cations. To date, most of these studies have primarily focused on the properties of binary systems. However, in comparison to ion–water binary systems, ternary systems that involve ions, water, and organic matter are more prevalent in nature and provide more realistic insights into biological processes. This study focuses on ion hydration in water and alcohol mixture using terahertz spectroscopy and x-ray diffraction (XRD). The results reveal a distinct behavior depending on the type of alcohol used. Specifically, the presence of both methanol and ethanol results in the disappearance of absorption peaks associated with NaCl hydrate at low temperatures. In contrast, tert-butanol does not exhibit such an effect, and isopropanol demonstrates a more complex response. By combining these terahertz spectroscopic findings with low-temperature XRD data, we gain insights into the formation, or lack thereof, of NaCl · 2H 2 O hydrate crystals. Crucially, our observations suggest a dominant correlation between the polarity of the alcohol molecules and its impact on the Na + hydration. Strongly polar alcohols preferentially solvating the Na + ion lead to the failure of hydrate formation, while weakly polar alcohols do not have this effect.
研究领域:
化学
·
物理学
·
生物物理学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Naner Li,Chaobao Wang,Zhenghao Ge,Xinqi Zou,Xiaoqian Weng
Water has many natural advantages for using as an ecological lubricant in engineering. However, how to ensure the efficiency and stability of water lubricating film with low viscosity has been always the key point of practical applications. For this, a strategy is given to improve lubricating capacity of water under loads by combining the biomimetic adhesion and hydration lubrication of polydopamine (PDA). The PDA nanoparticles were polymerized and purified, and its aqueous suspensions were used to solve the difficult problem of lubrication failure when using water as lubricant. The morphology characteristics and lubrication performance of PDA nanoparticles were experimentally tested and analyzed. The results showed that PDA nanoparticles can form an adhesive-lubricating film on the copper balls and effectively reduce the tribological behaviors in rubbing processes. This strategy that combines the biomimetic adhesion and hydration lubrication of PDA provides a novel method to realize targeted hydrated film and excellent water lubrication under load bearing conditions.
研究领域:
材料科学
·
生物仿生学
·
摩擦学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2016
·
IF 2.74
Yong Zhou,Yongli Huang,Zengsheng Ma,Yinyan Gong,Xi Zhang,Yi Sun,Chang Q. Sun
A combination of the differential Raman spectrometrics and contact-angle measurements has enabled resolution of the hydrogen bond (HB, O:H O) relaxation and molecular dynamics in the NaX hydration shells. Observations suggest that the aqueous ions create each an electric field to form the hydration shells through O:H O bond elongation and polarization. The ionic polarization shares the same, and even stronger, effect of molecular undercoordination that shortens the H O bond and stiffen its phonon , and meanwhile, the O O Coulomb repulsivity lengthen and soften the O:H nonbond with an association of polarization. O:H O bond electrification raises not only the structure order of molecules and the viscosity in the hydration shells but also the skin stress and thermal stability of the solution. Exercises not only deepen our insight into the salt solute-solvent interaction involved in the Hofmeister series in terms of O:H O bond electrification but also provide a powerful means quantifying the dynamic, local, molecular-site-resolved information regarding the O:H O bond cooperativity in aqueous solutions.
研究领域:
物理化学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
BIOORGANIC CHEMISTRY
·
2023
·
IF 5.1
Yangyang Sun,Zhuzhu Tang,Yanjun Li,Yongkang Song,Hualei Wang,Dongzhi Wei,Shengli Yang
Hydration, a secondary activity mediated by nitrilase, is a promising new pathway for amide production. However, low hydration activity of nitrilase or trade-off between hydration and catalytic activity hinders its application in the production of amides. Here, natural C-terminal-truncated wild-type nitrilase, mined from a public database, obtained a high-hydration activity nitrilase as a novel evolutionary starting point for further protein engineering. The nitrilase Nit-74 from Spirosoma linguale DSM 74 was successfully obtained and exhibited the highest hydration activity level, performing 50.7 % nicotinamide formation and 87.6 % conversion to 2 mM substrate 3-cyanopyridine. Steric hindrance of the catalytic activity center and the N -terminus of the catalytic cysteine residue helped us identify three key residues: I166, W168, and T191. Saturation mutations resulted in three single mutants that further improved the hydration activity of N -heterocyclic nitriles. Among them, the mutant T191S performed 72.7 % nicotinamide formation, which was much higher than the previously reported highest level of 18.7 %. Additionally, mutants I166N and W168Y exhibited a 97.5 % 2-picolinamide ratio and 97.7 % isonicotinamide ratio without any loss of catalytic activity, which did not indicate a trade-off effect. Our results expand the screening and evolution library of promiscuous nitrilases with high hydration activity for amide formation.
研究领域:
生物化学
·
分子生物学
·
酶工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2025
·
IF 3.5
Huhe Dule,Ma Zhengxiang,Zheng Jiali,Wang Yanji
2,5-Furandicarboxamide (FDA) is a promising bio-based platform compound for synthesizing high-value chemicals. Conventional synthesis methods, including strong acid/base-catalyzed reactions and ammonia oxidation, present significant environmental concerns and safety risks. In this paper, we investigated the performance of various oxide catalysts and the kinetics of the hydration reaction of 2,5-dicyanofuran (DCF) to produce FDA. The nanorod manganese oxide (NR-MnO 2 ) catalyst demonstrated remarkable efficacy, achieving an FDA yield of 97.5% at a reaction temperature of 110 °C over 2.5 h. Additionally, integrating cerium oxide (CeO 2 ) with NR-MnO 2 enhanced the selectivity for the single cyano hydration reaction. Specifically, the Mn 1 -Ce 0.25 oxide catalyst yielded 76.1% for 5-cyano- 2-furancarboxamide (DFFA) with an impressive selectivity of 89.2%. A kinetic model for the DCF hydration reaction was successfully developed using NR-MnO 2 as the catalyst. The model revealed that the initial stages involve the hydration of monocyano to form DFFA, followed by further hydration to form the FDA. Based on the Arrhenius model, the apparent activation energies were 48.5 kJ/mol and 35.4 kJ/mol, respectively. The results of this study provide a scientific foundation for the hydration of DCF in the production of DFFA or FDA, offering a more selective and environmentally friendly approach to the synthesis of bio-based amides.
研究领域:
化学工程
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Zhu Xiong,Yongshi Huang,Zehui Huang,Yiwen Shi,Fangshu Qu,Gaosheng Zhang,Jingxin Yang,Shuaifei Zhao
Membrane surface fouling is often reversible as it can be mitigated by enhancing the crossflow shear force. However, membrane internal fouling is often irreversible and thus more challenging. In this study, we developed a new superhydrophilic poly(vinylidene fluoride) (P-PVDF) membrane confined with nano-Fe3O4 in the top skin layer via reverse filtration to reduce internal fouling. The surface of the P-PVDF membrane confined with nano-Fe3O4 had superwetting properties (water contact angle reaching 0° within 1 s), increased roughness (from 182 to 239 nm), and enhanced water affinity. The Fe3O4@P-PVDF membrane surface showed a thicker and enhanced hydration layer, which prevented foulants from approaching membrane surfaces and pores, thereby improving the rejection. For example, when 50 ppm humic acid (HA) solution was used as the feed, the removal efficiency of the Fe3O4@P-PVDF membrane was ∼67%, while the HA removal of the P-PVDF membrane was only ∼20%. The results from the resistance-in-series model showed that nanoconfinement of Fe3O4 in the top skin layer of the membrane allowed foulants to accumulate on the membrane surface (i.e., surface fouling) rather than within the internal pores (i.e., internal fouling). The filtration results under crossflow fouling and cleaning confirmed that the Fe3O4@P-PVDF membrane had higher surface fouling but it was much more reversible and much lower internal fouling compared with the control membrane. Our fouling analysis offers new insights into mass transfer mechanisms of the membrane with a nanoconfinement-enhanced hydration layer. This study provides an effective strategy to develop membranes with low internal fouling propensities.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2019
·
IF 3.683
Hongtao Cai,Ran Kou,Guangming Liu
In this work, poly(sodium styrene sulfonate) brushes have been employed as a precursor to prepare thermosensitive strong polyelectrolyte brushes (SPBs) through a counterion exchange strategy. The substitution of hydrophilic Na+ counterions by hydrophobic tetraalkylphosphonium counterions leads to a thermoresponsivity of the SPBs. The thermosensitive properties including hydration, stiffness, and surface water wettability of the SPBs can be modulated by the type of the tetraalkylphosphonium counterions. Nevertheless, the wet thickness of the SPBs with tetraalkylphosphonium counterions does not exhibit an obvious temperature dependency due to the high steric barrier in the crowded environment of SPBs generated by the large tetraalkylphosphonium counterions. The mixtures of small Na+ counterions and large tetraalkylphosphonium counterions are employed to realize the thermosensitive wet thickness without sacrificing other thermoresponsive properties of the SPBs because the mixed counterions can bring both a certain hydrophobicity and some free space to the brushes. This work opens up the opportunities available for the use of counterions to tune the thermosensitivity of SPBs.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Research Express
·
2024
·Vol. 11
·期 8
·085310
·
IF 1.8
Yunhai Shi,Kai Lu,Zejian He,Yulong Chen,Mi Zhou
Water reducing agent as an important admixture. It is used to decrease the initial water content in cement paste, improving its fluidity. Polycarboxylic acid water reducing agent (PCE) is a high-performance type with advantages such as low dosage, high water reduction rate, environmental friendliness, and a simple synthesis process. In this study, the third monomer (TPEG-SAA-SHES) was synthesized by modifying isopentenol polyoxyethylene ether (TPEG) with sodium hydroxyethyl sulfonate (SHES). Subsequently, a modified ether polycarboxylic acid-based water reducing agent (PCE-S) was synthesized with TPEG and acrylic acid (AA). The experimental conditions for the synthesis of PCE-S were optimized through orthogonal tests. The synthesized PCE-S showed a certain degree of improvement in the initial net slurry flow compared to PCE, with a maximum enhancement of 19.64%. The adsorption increased by 18.25% when the TSS dosage was 5%. PCE-S enhances the hydration products of cement, increasing the compactness of the structure. The product is environmentally friendly, safe, and durable, effectively reducing the dosage of additives and helping to cut costs. It lays the foundation for the next industrialized mass production.
研究领域:
建筑材料化学
·
高分子材料合成
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2016
·
IF 3.993
Ge Wang,Peiyi Wu
In this paper, one LCST-type thermoresponsive poly(ionic liquid) (PIL), poly(tetrabutylphosphonium styrenesulfonate) (P[P4,4,4,4][SS]), was introduced to poly(N-isopropylacrylamide) (PNIPAM) by two different ways, mixing and copolymerization. Interestingly, they show distinct thermoresponsive phase transition behaviors, evidenced by temperature-variable 1H nuclear magnetic resonance and Fourier transform infrared in combination with the perturbation correlation moving window (PCMW) technique. The PNIPAM/P[P4,4,4,4][SS] mixture exhibits a sharp and drastic phase transition, similar to that of pure PNIPAM. In the statistical copolymer, PNIPAM-co-P[P4,4,4,4][SS], the thermosensitivity of P[P4,4,4,4][SS] is largely suppressed, resulting in a linear, mild, and incomplete phase transition, which has never been reported before. This abnormal phenomenon is shown to arise from the outstanding hydration ability of P[P4,4,4,4][SS]. Our findings should be conducive to improving our understanding of the interaction between LCST-type polymers with distinct structures and provide a new perspective for preparing thermoresponsive materials with linear phase transition behavior.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Leyang Lv,Shitao Luo,Branko Šavija,Hongzhi Zhang,Lin Li,Tamon Ueda,Feng Xing
The particle size distribution (PSD) has a significant influence on the fresh and final properties of cement and its derived products. In this paper, CSA cements with three different mean diameters (D 50 ), ranging from 6.04 to 26.62 μm were prepared by milling. The pre-hydration behavior was quantitatively analyzed, including the degree of pre-hydration, the dynamic change of mineral assemblage and the morphology of the prepared CSA cement exposed to 57%, 75% and 97% relative humidities (RHs) for up to 90 days. Hydration kinetics, porosity, and compressive strength of the cement paste made with fresh and pre-hydrated CSA cement with different PSD were also characterized. The results show that pre-hydration of CSA cement at RH higher than 75% has detrimental effects on the hydraulic activity and strength gain of CSA cement. However, coarser CSA cement (D 50 = 26.62 μm) does not only show better resistance to pre-hydration, but also higher compressive strength and lower porosity.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
Biomaterials Science
·
2017
·Vol. 5
·期 11
·2251-2267
·
IF 4.21
Jie Wu,Kunxi Zhang,Xi Yu,Jianxun Ding,Lei Cui,Jingbo Yin
The key barrier to the clinical application of tissue engineering scaffolds is the limitation of rapid and sufficient vascularization. Adipose-derived stem cells (ASCs), especially multicellular aggregates, exhibited a promising angiogenic activity. Herein, we designed a series of poly(L-glutamic acid) (PLGA)-based hydrogels with tunable hydration to control the in situ formation of multicellular spheroids. Oligo(ethylene glycol)s (OEGs) were employed to regulate the hydration of hydrogels. The hydrogel cross-linked with ethylene glycol (OEG1) supported the most excellent adhesion and proliferation of human ASCs in vitro. However, as the hydration of hydrogels strengthened, the adherent ASCs were gradually replaced with multicellular spheroids. Moreover, the in situ formation of spheroids was more effective in upregulating hypoxia-adaptive signals (e.g., hypoxia-inducible factor-1α, HIF-1α) and enhancing the secretion of angiogenic factors (e.g., vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF-2)) compared to adherent cells in OEG1 hydrogels. The hydrogel cross-linked with oligo(ethylene glycol)400 (OEG9) carrying spheroids induced a high angiogenic response of host tissue in vivo, resulting in an improved system vascularization, compared to adherent cells in the OEG1 hydrogel. These features indicated that the PLGA-based hydrogels were expected to be applied toward bone and fat tissue regeneration.
研究领域:
组织工程
·
生物材料
·
再生医学
·
细胞生物学
·
血管生成
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）