Crystals
·
2017
·Vol. 7
·期 4
·99
·
IF 1.566
Hongqiang Gao,Wenjuan Wei,Liyuan Dong,Guoqiang Feng,Xingxing Jiang,Rong Wu,Zheshuai Lin,Wei Li
The elastic properties of a zeolitic metal-azolate framework, Zn(mtz)2(MAF-7, mtz−= 3-methyl-1,2,4-triazolate), have been examined from the view point of the first principles calculations and experiments. Our results demonstrate that the three independent elastic constants of MAF-7 are about 5.0–73.3% higher than those of ZIF-8, though they are isomorphic. The electron-donating effect of the nitrogen atom at the 2-position in mtz- ring dominantly accounts for such a prominent difference. The detailed analysis of the full elastic tensors reveals that the volume moduli, shear moduli, and Poisson’s ratios of MAF-7 are about 3.4% to 20.1%, 3.2% to 20.6%, and −30.3% to 12.3% higher than those of ZIF-8. The underlying structural reasons were discussed to explain the anisotropic difference of those properties. Moreover, the conclusion deduced from first-principle calculations was also been verified by nanoindentation and high-pressure synchrotron X-ray diffraction measurements.Keywords:zinc-triazolate framework;elastic constants;volume moduli;shear moduli;Poisson’s ratios
研究领域:
材料科学
·
物理化学
·
机械工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Jinming Li,Heng Li,Chengwei Wu,Wei Zhang
The self-healing ability of articular cartilage is poor, and hydrogel materials are expected to be used for cartilage replacement due to their high-water content and good biocompatibility. Here, the polyvinyl alcohol-acrylamide-agarose multi-network hydrogel was proposed. The hydrogel has a compressive modulus of 1.19 MPa and a compressive strength limit of 8.87 MPa, as well as a tensile modulus of 0.63 MPa and a tensile strength limit of 1.08 MPa. The mechanical properties of hydrogel meet the requirement for cartilage replacement materials. The in vitro cell experiments indicate that the introduction of agarose improves the cell adhesion of the hydrogel, which is expected to be beneficial in the field of biomedicine.
研究领域:
生物医学工程
·
材料科学
·
组织工程
✓ 已验证
产品关联
DOI
高影响因子
Gels
·
2025
·Vol. 11
·期 8
·578
·
IF 5.3
Yancheng Yan,Tao Tang,Biao Ou,Jianzhong Wu,Yuan Liu,Jingbin Yang
In petroleum exploration and production, lost circulation not only significantly increases exploration and development costs and operational cycles but may also lead to major incidents such as wellbore instability or even project abandonment. This paper constructs a polymer gel plugging system by optimizing high-molecular-weight polymers, crosslinker systems, and resin hardeners. The optimized system composition was determined as 1% polymer J-1, 0.3% catechol, 0.6% hexamethylenetetramine (HMTA), and 15% urea–formaldehyde resin. Experimental studies demonstrated that during the initial stage (0–3 days) at 120 °C, the optimized gel system maintained a storage modulus (G′) of 17.5 Pa and a loss modulus (G″) of 4.3 Pa. When the aging period was extended to 9 days, G′ and G″ decreased to 16 Pa and 4 Pa, respectively. The insignificant reduction in gel strength indicates excellent thermal stability of the gel system. The gel exhibited superior self-filling capacity during migration, enabling complete filling of fractures of varying sizes. After aging for 1 day at 120 °C, the plugging capacity of the gel system under water flooding and gas flooding conditions was 166 kPa/m and 122 kPa/m, respectively. Furthermore, a complete gel barrier layer formed within a 6 mm wide vertical fracture, demonstrating a pressure-bearing capacity of 105.6 kPa. This system shows good effectiveness for wellbore isolation and fracture plugging. The polymer gel plugging system studied in this paper can simplify lost circulation treatment procedures while enhancing plugging strength, providing theoretical support and technical solutions for addressing lost circulation challenges.
研究领域:
石油工程
·
钻井液
·
高分子科学
·
油藏工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 7
·49856
·
IF 2.52
Donglei Liu,Xufeng Dong,Huiying Liu,Yiping Zhao,Min Qi
Motivated by a need to replicate structural and viscoelastic properties of soft tissue, such as cartilage, the structural hydrogels with viscoelastic feature have been of interest in biomedical application. However, the effect of pore alignment on their viscoelastic properties has been largely underestimated. This work prepared cellulose nanocrystal (CNC)/collagen hydrogels with different pore orientations, including horizontally aligned pores, random pores and vertically aligned pores, and integrated them into a multilayered hydrogel with multi-structure which mimics cartilage construct. The stress relaxation rate (τ 1/2 ), creep rate (γ 1/2 ), storage modulus ( G′ ) and loss modulus ( G″ ) increased in the order of the vertical, random, multi-structural, and horizontal. G′ value of the horizontal increased up to 300% relative to the vertical in the strain amplitude and frequency sweep. Maxwell–Weichert and Variable Network Density models were used to explain phenomena, and the experimental curves fitted well with the theoretical models. These results reveal that the viscoelastic properties of hydrogel can be influenced by pore orientation except conventional component concentration.
研究领域:
生物材料
·
组织工程
·
生物力学
·
高分子科学
·
再生医学
✓ 已验证
DOI
高影响因子
SOLID STATE COMMUNICATIONS
·
2024
·
IF 2.1
Lun Xiong,Mingquan Jiang,Fang Miao,Sheng Jiang
In this study, niobium diboride (NbB 2 ) was investigated using synchrotron radiation X-ray diffraction in a diamond anvil cell to analyze their compressive behavior at room temperature. The volume of the NbB 2 was fitted to its corresponding highest pressures of 32.2 GPa without experiencing structural phase transitions, leading to the determination of bulk modulus of 389(7) GPa. Additionally, we further investigated the bulk modulus, band structure and density of states of NbB 2 to 35 GPa by density functional theory. The results yielded a bulk modulus of 285 GPa for NbB 2 . Importantly, it was observed that NbB 2 demonstrates both metallic and non-magnetic properties throughout the pressure range. In addition, we studied the deviatoric stress of NbB 2 at high pressure using linewidth analysis method. It was found that NbB 2 can support a maximum differential stress of 14.2 GPa at the pressure of 17.3 GPa.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2025
·
IF 6.6
Lihua Zhang,Yuli Ning,Yingying Xin,Yinjiao Wei,Xinfang Liu,Bakht Ramin Shah,Xiaofan Zhang,Wei Xu
This study investigates the effects and underlying mechanisms of freeze-thawing on the mechanical properties of Pickering emulsion gels composed of konjac glucomannan/κ-carrageenan (KGM/CRG) induced by K 2 CO 3 . The results showed that as the number of freeze-thaw cycles increased, syneresis and water loss during the squeezing of the gels significantly rose, while their shear strength gradually increased. After two freeze-thaw cycles, the gel exhibited maximum hardness. Microstructural analysis revealed that ice crystals disrupted the original gel network, leading to the aggregation of oil droplets and the dissipation of water. During freezing, the crystallization of water enhanced interactions among polysaccharide molecules, resulting in a more robust and denser KGM-CRG network. X-ray diffraction analysis confirmed an increase in the crystallinity of the gel following freeze-thaw cycle treatment. Furthermore, compared to fresh samples, the freeze-thawed emulsion gels displayed higher storage and loss modulus. These findings suggest that Pickering emulsion gels show increased mechanical properties after treatment. Additionally, this study illustrated the potential mechanisms by which freeze-thaw treatment modifies the microstructure of Pickering emulsion gels and influences their gel properties, providing a theoretical foundation for the design of emulsion-gel foods through freeze-thaw cycle treatment.
研究领域:
食品科学
·
高分子科学
·
胶体与界面科学
·
材料工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·
IF 13.3
Dengfeng Zhang,Xiujuan Li,Junyue Li,Qiye Wang,Xuemei Dong,Yueyue Wu,Zifan Li,Xinyi Xie,Zhengdong Liu,Fei Xiu,Wei Huang,Juqing Liu
Ionogels are extremely soft ionic materials that can undergo large deformation while maintaining their structural and functional integrity. Ductile ionogels can absorb energy and resist fracture under external load, making them an ideal candidate for wearable electronics, soft robotics, and protective gear. However, developing high-modulus ionogels with extreme toughness remains challenging. Here, a facile one-step photopolymerization approach to construct an acrylic acid (AA)-2-hydroxyethylacrylate (HEA)-choline chloride (ChCl) eutectogel (AHCE) with ultrahigh modulus and toughness is reported. With rich hydrogen bonding crosslinks and phase segregation, this gel has a 99.1 MPa Young's modulus and a 70.6 MJ m −3 toughness along with 511.4% elongation, which can lift 12 000 times its weight. These features provide extreme damage resistance and electrical healing ability, offering it a protective and strain-sensitive coating to innovate anticutting fabric with motion detection for human healthcare. The work provides an effective strategy to construct robust ionogel materials and smart wearable electronics for intelligent life.
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 Applied Materials & Interfaces
·
2025
·
IF 8.2
Baijun Li,Meiqing Guo,Xiaojun Wang,Liyong Qiao,Hui Song,Zhiqiang Li
The effectiveness of hard orthokeratology (OK) lenses in controlling myopia has been confirmed in clinical practice. However, there exist defects including wear discomfort, limited regulation of mechanical properties and geometry, and effectiveness inconsistency with the expected efficacy. Herein, we analyze the relationship between the mechanical properties of OK lenses and the vertex displacement of the human cornea through the finite element model. It is noted that the expected corneal deformation of 15–20 μm can be achieved by soft OK lenses with an elasticity modulus above 9 MPa, which is far lower than the 2.7 GPa of commercial OK lenses. No obvious displacement difference occurred when the elasticity modulus of the OK lenses exceeded 200 MPa. Thus, we propose the hypothesis of soft OK lenses based on hydrogel materials for controlling myopia. The soft OK lenses are fabricated by a two-step 3D printing technology using a multicomponent bioink containing methyl methacrylate, hydroxyethyl methacrylate, polyethylene glycol diacrylate, and 3-(trimethoxysilyl)propyl methacrylate (KH-570). The printed OK lenses possess comfort wear, high light transmittance, smooth surface, regulated elasticity modulus (from 33 to 535 MPa) and geometry, and excellent biocompatibility. Additionally, the effectiveness of soft OK lenses is confirmed through a porcine corneal model with obvious corneal deformation comparable to that of the commercial ones. This study demonstrates the feasibility of soft OK lenses for controlling myopia and provides support for the design and fabrication of soft OK lenses for comfortable wear.
研究领域:
生物医学工程
·
眼科研究
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2024
·
IF 4.5
Chong Wang,Pei-Yi Liu,Ze-Zhong Lin,Yu Chen,Hai-Chao Li
Numerous plasticizers have been developed to acquire the traditional soft poly(vinyl chloride) (PVC) that is characteristic of a high elongation at break, but a low modulus of <70 MPa. Special highly-stretchable PVCs with high modulus (>70 MPa) are highly desirable for widening the application fields of PVC materials. Herein, a series of star copolymers with hyperbranched polyethylenimine (PEI) as core and poly(ε-caprolactone) (PCL) as shell (PEI-PCL) were utilized as plasticizers to prepare functional highly-stretchable semi-rigid plasticized PVC materials. Under the 0.5 weight ratio of PEI-PCL to PVC, the obtained plasticized PVCs showed the highest modulus of around 392 MPa under the assuring of >400% elongation at break, which was nearly four-fold of the most rigid plasticized PVC materials ever-reported. Through the further DSC and FTIR characterizations and the comparison with linear PCL plasticizers, the reason for so rigidity was ascribed as that the guest-encapsulation capability of PEI-PCLs led to the physical crosslinking of PVC chains by the amidated PEI core through the dense hydrogen-bonds. Furthermore, PEI-PCLs could disperse hydrophilic dyes homogeneously into PVC matrix, resulting in colorful or photoluminescent PVC materials.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2021
·
IF 5.985
Cong Du,Xin Ning Zhang,Tao Lin Sun,Miao Du,Qiang Zheng,Zi Liang Wu
Forming robust associative interactions has been an effective strategy for the design of tough hydrogels. However, the role of associative interactions in the dynamics of hydrogels still remains elusive. Here, we report a series of poly(acrylamide-co-methacrylic acid) hydrogels with moderate water contents and excellent mechanical properties that are facilely synthesized by free-radical copolymerization. The mechanical properties of these hydrogels vary with the feeding molar fraction of acrylamide (fam). The gels with fam of 0.2–0.35 exhibit high toughness and good stability in water, which is related to the dense hydrogen bonds and relatively high segment rigidity of the matrix. Dynamic modulus spectra extended by time-temperature superposition and relaxation measurements indicate that the gels undergo glassy-to-rubbery transition with decreased frequency, and the robust hydrogen bonds, whose density is 1–3 times that of entanglements, retard chain disentanglement and contribute to the plateau modulus of the gels at low frequencies. The activation energy for the dissociation of the robust hydrogen bonds is ∼46 kJ mol–1. Furthermore, a decrease in water content results in the shift of dynamic modulus spectra to low frequencies and an increase in transition temperature due to the reduced segment relaxation. To further examine the structure of gel networks, the tensile behaviors of the gels are analyzed using a viscoelastic model. It is found that each partial chain includes 20–30 Kuhn segments, which are stretched after the fracture of intrachain hydrogen bonds to release the hidden length, dissipate energy, and thus toughen the gels. This understanding of the dynamics of the network at different timescales and the contribution of associative interactions to the mechanical properties should be informative for the design of other tough hydrogels.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Haoji Lao,Nafeesa Mushtaq,Guofei Chen,Bingyang Wang,Yuxia Ba,Xingzhong Fang
Two new series of transparent polyamide-imides (PAIs) with high modulus and low coefficient of thermal expansion (CTE) were prepared by random or block copolymerization of 4,4′-biphthalic dianhydride (BPDA) and p -phthaloyl chloride (TPC) with 2,2′-bis(trifluoromethyl)benzidine (TFDB). These series of PAIs displayed low CTE of 16–42 ppm/K, good mechanical properties with high tensile modulus ranging from 4.9 to 6.6 GPa, tensile strengths of 112–170 MPa and elongations at break of 2.0–5.4%, as well as high transparency with transmittances at 500 nm (T 500nm ) of 84–87%, which was greatly affected by the feed ratio of monomer BPDA & TPC, and the block length caused by block polymerization. The block copolymer PAI-3-B1 presented the best comprehensive performance with high transparency (T 500nm ) of 87%, low CTE of 16 ppm/K and high tensile modulus of 6.1 GPa.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Yongqi Feng,Piming Ma,Pengwu Xu,Ruyin Wang,Weifu Dong,Mingqing Chen,Cornelis Joziasse
The effects of six nucleating agents (NAs), i.e., orotic acid (OA), potassium salt of 3,5-bis(methoxycarbonyl)benzenesulfonate (LAK-301), substituted-aryl phosphate salts (TMP-5), talc (TALC), N' 1 , N' 6 -dibenzoyladipohydrazide (TMC-306) and N 1 , N 1′ -(ethane-1,2-diyl)bis( N 2 -phenyloxalamide) (OXA), on the crystallization behavior of poly(lactic acid) (PLA) were compared by DSC . Under the same dosing of 0.5 wt%, the nucleation effect of the NAs for PLA declines in the order of TMC-306 ≈ OXA > TALC ≫ TMP-5 ≈ LAK-301 ≈ OA. The nucleation efficiency (NE) of TMC-306 and OXA is around 50%, which is almost 2 times of the NE of TALC. In the best case of the PLA/TMC-0.5% sample, the half-time of crystallization decreases from 30 s to 9 s with decreasing the crystallization temperature from 120 °C to 100 °C, which is of great significance to the fast production of highly crystallized PLA materials. As high-efficient NAs, TMC-306 and OXA are able to accelerate the crystallization rate of PLA even upon fast cooling at 50 °C/min, while make no difference on PLA crystal form, as identified by WAXD . DMA analysis shows that the storage modulus of PLA is significantly improved by TMC-306 and OXA.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）