RSC Advances
·
2016
·Vol. 6
·期 64
·59131-59140
·
IF 3.289
Jia Yang,Lin Zhu,Xiaoqiang Yan,Dandan Wei,Gang Qin,Baozhong Liu,Shuzheng Liu,Qiang Chen
Polymer nanocomposite hydrogels (NC gels) have been intensively investigated for applications in academic and industrial fields. In the present work, hybrid cross-linked polyacrylamide (PAAm)/LAPONITE® hydrogels were synthesized by in situ free radical polymerization using LAPONITE® nanoplatelets and N,N-methylenebisacrylamide (MBA) as physical and chemical crosslinkers, respectively. We aimed to make clear the synergistic effect of physical and chemical crosslinking on the mechanical properties, self-recovery, fatigue resistance and self-healing performances of hybrid PAAm/LAPONITE® NC gels. The effects of LAPONITE® and chemical cross-linker concentration on the mechanical properties of the physical and hybrid NC gels were investigated in details. It was found that the fracture stress and fracture energies of hybrid NC gels decreased sharply as the chemical crosslinker (MBA) concentration became larger than 0.05 mol% of monomer. With a very small amount of chemical crosslinker, the hybrid NC gels exhibited improved tensile properties, large hysteresis and good self-recovery performances. The best tensile properties of hybrid NC gels in this study were σf of 0.45 MPa, εf of 50.63 mm mm−1, E of 72.64 kPa and W of 9.81 MJ m−3, which were much better than those of physical NC gels and pure chemical gels. However, it was also revealed that there was a negative effect from chemical crosslinking on the fatigue resistance and self-healing properties of NC gels. A deformation and recovery mechanism was also proposed. We believe this work will provide better understanding about the relationship of network structure and properties for hybrid NC gels.
研究领域:
材料科学
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聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2024
·
IF 1.9
Xinyuan Li,Meifei Niu,Junjie Zhang,Zhuoping Yu,Jun Xu,Guangyu Sun
Wax precipitation and deposition are challenging hurdles in pipeline transportation of waxy crude oil. This study focuses on transforming SiO2, Laponite, and montmorillonite particles into hydrophobic particles through polymer grafting. Chemical structure analysis and grafting ratio calculation were performed. Through thermogravimetric analyzer (TGA) test, Laponite showed the highest grafting ratio. The effects of adding nanocomposites, TDA-2024-22, and commercial pour point depressants on the rheological behavior and wax crystallization behavior of African crude oil were compared. Addition of the nanocomposite PDA-22@SiO2 to crude oil, reduced the viscosity by 85.6% at 20 °C and the thixotropy by 60.2%. Wax crystal size decreased in the order of PDA-22@SiO2, PDA-22@Laponite, KS-10, TDA2024-22, and PDA-22@MMT. The pour point decreased by 6 °C with PDA-22@ SiO2 particles but only 3 °C with Laponite and montmorillonite composites. Spherical nanocomposites are promising flow improvers for waxy crude oil.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2017
·
IF 2.714
Feng Yan,Xinping Zhang,Huihui Ren,Xiaohui Meng,Dong Qiu
The application of patched laponite-polymer composite particles (LCPs) in hydrogel reinforcement has been proposed and such hydrogels (LC hydrogels) were successfully prepared. LCPs can be well dispersed in hydrogel matrix to rather high particle concentration and at the same time, form chemical bonding with polymer matrix through copolymerization of surface C C groups. The obtained LC hydrogels showed more homogeneous microstructure and significantly higher mechanical strength comparing with the hydrogel containing bare laponite or laponite surface modified with C C groups at same particle content. A series of control experiments reveals that both the surface chemistry and patched morphology were essential to produce such good reinforcement performance.
研究领域:
材料科学
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生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2013
·
IF 3.172
Ying Yang,Zhi Liu,Dayong Wu,Man Wu,Ye Tian,Zhongwei Niu,Yong Huang
We investigated the effect of amphiphilic Laponite nano-discs, which were edge-modified by hydrophobic chains, on the properties of Pickering emulsions and Pickering emulsions polymerization. Comparing to unmodified Laponites, these amphiphilic nano-discs can greatly reduce the surface tension, resulting in very stable Pickering emulsions. These particles uniquely combine the Pickering effect with amphiphilic properties similar to the surfactant . Taking advantage of these amphiphilic Pickering emulsifiers , miniemulsion polymerization of styrene was performed. Homogeneous polystyrene nanoparticles with size around 150 nm could thus be prepared.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Zhe Li,Cong Li,Wei Sun,Yuan Bai,Zhou Li,Yulin Deng
Implantable and wearable transient electronics based on nanogenerators have been applied in self-powered sensing, electrical-stimulation therapy, and other fields. However, the existing devices have a poor ability to match with the shapes of human tissues, and the degradation processes cannot meet individual needs. In this work, a PEGDA/Lap nanocomposite hydrogel was prepared that was based on biocompatible polyglycol diacrylate (PEGDA) and laponite, and a biodegradable single-electrode triboelectric nanogenerator (BS-TENG) was built. The PEGDA/Lap hydrogel has enhanced flexibility and mechanical and electrical performance. Its strain was 1001.8%, and the resistance was 10.8. The composite hydrogel had a good biocompatibility and could effectively promote the adhesion of cells. The BS-TENG could be used as a self-powered device to light an LED and serve as an active sensor for real-time monitoring of breath and various human movements. More importantly, the device could be degraded controllably without any harm. Therefore, BS-TENGs will be mainstream in diagnosis and treatment and play an important role in biomedical science.
研究领域:
生物医学工程
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材料科学
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纳米技术
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生物相容性
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传感器
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 49
·43663-43671
·
IF 3.289
Changpeng Li,Changdao Mu,Wei Lin
Methacrylated gelatin (MA-gelatin) is a gelatin derivative synthesized by the reaction with methacrylic anhydride; the degree of substitution (DS) of primary amines by methacrylamide groups in the gelatin is closely related to the dosage of methacrylic anhydride. In this work, MA-gelatin has been developed as a macromolecular crosslinker to prepare novel nanocomposite hydrogels (NC gels) based on polyacrylamide (PAAm) and LAPONITE® nanoclay. Compared with unmodified gelatin, MA-gelatin improves the stability of the LAPONITE® suspension in the pre-gel system. FTIR results confirm the success of gelatin modification, in agreement with the 1H NMR result, and the copolymerization of MA-gelatin and acrylamide monomers in the NC gel network. The increasing DS of MA-gelatin thus reduces the equilibrium swelling ratio (ESR) and pore sizes, and enhances the mechanical properties of the NC gels, due to the macromolecular crosslinking effect. Unlike the small molecular crosslinker N,N′-methylenebisacrylamide (BIS), MA-gelatin shows a stronger influence on the swelling behaviours and mechanical properties of NC gels. Moreover, the MA-gelatin crosslinked NC gels exhibit decreased bovine serum albumin (BSA) adsorption, prolonged blood-clotting time and nonhemolytic nature, indicating the improved antithrombogenicity. The results show that MA-gelatin can be a hemocompatible macromolecular crosslinker for the fabrication of biomedical materials.
研究领域:
生物材料
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组织工程
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医学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Rongnan Guo,Jianli Wang,Shunlong Zhang,Wei-Qiang Han
One of major issues of lithium-sulfur batteries is the lithium polysulfides shuttling effect which decreases utilization of sulfur and cycling stability. Besides, low lithium-ion diffusion, causing serious polarization, limits to achieve lithium-sulfur batteries with high rate capability. Herein, a multifunctional polymer-Laponite nanocomposite binder, cross-linked by chemical and physical cross-linkers, was prepared for sulfur cathode. In this binder, the polymer and cross-linked structure can drastically increase the uniform dispersion of active materials and the adhesion property. The Laponite, a physical cross-linker, can effectively enhance the lithium-ion transfer and greatly retard the shuttle effect, leading to low polarization and high capacity at high rate. Therefore, the polymer-Laponite nanocomposite binder can significantly improve the cycling performance and high-rate capability of the electrode. The electrode with this binder exhibits a reversible capacity of 593 mAh g −1 after 500 cycles at 0.5 C, which is much higher than that of PVDF.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
Biomolecules
·
2022
·Vol. 12
·期 8
·1089
·
IF 6.064
Liying Zhang,Gao He,Yang Yu,Yu Zhang,Xiang Li,Shige Wang
In recent years, multifunctional hydrogels have received a great deal of attention because they are biocompatible and can mimic the extracellular matrix. Herein, we prepared hydrogels of biocompatible cross-linked networks with photothermal properties. In this study, a chitosan/polyaniline/laponite (COL) hydrogel with photothermal conversion capability was designed. Polyaniline was firstly grafted onto chitosan and its solution was mixed with oxidized dextran, which was then cross-linked into a hydrogel via a Schiff base reaction. Furthermore, an aluminosilicate clay material, laponite (LAP), was incorporated into the hydrogel. The swelling ratio of the COL hydrogel in various solutions was greater than 580%, and it showed good degradation ability (the mass–loss ratio was over 45% after 28 days). This composite hydrogel was demonstrated to have good photothermal conversion properties and biocompatibility at both the cell (cell viability was over 97%) and animal levels. The COL hydrogel showed a photothermal conversion efficiency of 23.7% under the irradiation of a near-infrared laser. Coupled with the osteogenic differentiation-inducing potential of LAP, the COL hydrogel has the potential to kill tumors via hyperthermia or serve as scaffolds for bone tissue regeneration.Keywords:hydrogel;chitosan;polyaniline;photothermal;biocompatibility
研究领域:
材料科学
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生物医学工程
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2017
·
IF 3.101
Yun Tan,Shimei Xu,Ronglan Wu,Juan Du,Jilong Sang,Jide Wang
A gradient Laponite (Lap)-crosslinked nanocomposite (NC) hydrogel was fabricated by a facile electrophoresis method based on colloidal property of Lap, as well as interaction between Lap and thermo-responsive monomers . TGA , FTIR, SEM and TEM were used to characterize the gradient structure. The gradient NC hydrogel exhibited both gradient distribution of Lap and thermo-responsive polymers under the induction of direct current electric field (DC-EF). The gradient NC hydrogel showed anisotropic mechanical properties and gradient thermo-response along the direction of DC-EF. The mechanical strength of the gradient NC hydrogel increased by 38% compared with isotropic NC hydrogel. An increase in Lap content would improve the mechanical property and extend the strength range in different locations of the gradient hydrogel. Meanwhile, the compressive strength of the gradient NC hydrogels can also be adjusted in the range of 117–1774 kPa by changing the concentration of Lap. The work enabled the gradient NC hydrogels to apply in the field of tissue engineering and provided a new insight into development of novel bionic materials.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2014
·
IF 2.613
Hua Tan,Wenxia Liu,Dehai Yu,Haidong Li,Martin A. Hubbe,Bei Gong,Wei Zhang,Huili Wang,Guodong Li
Alkenyl succinic anhydride (ASA) is a widely used paper sizing agent that is applied in the form of oil-in-water (o/w) emulsions in order to impart a water-resistant character to the resulting paper. To obtain stable o/w emulsions of ASA, laponite, a highly hydrophilic synthetic clay, was selected as the stabilizer after it had been modified with tetramethylammonium chloride (TMAC), a quaternary ammonium salt with the shortest possible hydrocarbon groups. It was found that the TMAC moderately neutralized the negative charges of laponite particles, lowered the apparent viscosity, but enhanced the turbidity of laponite aqueous dispersion by enhancing the hydrophobicity of the laponite particles, favoring adsorption of laponite particles on the ASA–water interface. Meanwhile, the TMAC significantly decreased the interfacial tension between ASA and water/aqueous laponite dispersion, promoting the formation of an emulsion with small droplets. When the added amount of TMAC reached 1 wt% based on laponite, the as-prepared ASA emulsion had small droplet size, low viscosity and uniform droplet size distribution, and exhibited good creaming/coalescence stability. By using TMAC to modify laponite nanoparticles , the hydrolysis stability and sizing performance of ASA emulsion were also improved.
研究领域:
材料科学
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胶体化学
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造纸工业
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2024
·
IF 5.3
Gaokuo Du,Huanrong Li,Zixuan Li,Xinchi Ye,Yige Wang
Quaternary ammonium/phosphine cations added to the platelets of Laponite clay can lead to the remarkable enhancement of luminescence efficiency of the europium (III) β-diketonate complex. The mechanism for the luminescence boosting by the organic cations was elucidated by comparing two diketonate ligands with different pKa and the pH value of the selected organic salts based on the stationery and time resolved spectroscopy. It can be concluded as that the presence of the quaternary ammonium or quaternary phosphine cations helps to form Eu 3+ -β-diketonate complexes with high coordination numbers by decreasing the acidic sites on the platelet surface of laponite clay. Our work further strengthens the simplicity and generalization of obtaining highly luminescent materials and provides a unique insight into the function of the quaternary ammonium/quaternary phosphine cations in boosting the luminescence of lanthanide-based organic-inorganic hybrid materials.
研究领域:
材料科学
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Membranes
·
2025
·
IF 9.5
Zhijiang Sun,Xianya Wu,Yumeng Wang,Yu Jiang,Tao Yao,Shengtao Niu,Jianzhou Niu,Dahui Wang,Zehua Yin,Fen Ran
Many high-performance ultrafiltration membranes have been developed to address pollutant removal in complex water environments. However, the permeability-selectivity trade-off and inherent instability issues remain unresolved. In this study, a dense ultrafiltration membrane modified with laponite nanosheets is fabricated for selective separation and purification. The laponite nanosheets exhibit excellent compatibility with the polyethersulfone matrix, owing to their well-defined dimensions, distinctive physicochemical properties, and the dispersing role of polyvinylpyrrolidone, resulting in a membrane with synergistic performance characteristics. The modified membrane demonstrates a high pure water flux (106.3 L m -2 h -1 ), near-complete rejection of Congo red (>99.9 %), and high rejection rate of Methylene blue (89.8 %). Within a wider pressure range (0.1-3.0 MPa), the permeation flux maintains a linear relationship with increasing pressure, while the rejection rate for Congo red is nearly 100 %. In addition, under a high pressure of 2.0 MPa, laponite nanosheet-modified polyethersulfone membrane exhibits high stability and good separation performance under high-pressure conditions. These attributes significantly enhance separation precision and operational reliability in dye wastewater systems, indicating strong potential for practical application.
研究领域:
材料科学
·
环境工程
·
膜技术
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水处理
·
纳米复合材料
✓ 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）