Materials
·
2022
·Vol. 15
·期 4
·1367
·
IF 3.748
Fubing Gui,Yong Huang,Menghan Wu,Xilai Lu,Yongming Hu,Wanping Chen
A high long-term stability is crucial for room-temperature gas-sensitive metal oxide semiconductors (MOSs) to find practical applications. A series of Pd-SnO2mixtures with 2, 5, and 10 wt% Pd separately were prepared from SnO2and Pd powders. Through pressing and sintering, Pd-SnO2composite nanoceramics have been successfully prepared from the mixtures, which show responses of 50, 100, and 60 to 0.04% CO-20% O2-N2at room temperature for samples of 2, 5, and 10 wt% Pd, respectively. The room-temperature CO-sensing characteristics were degraded obviously after dozens of days’ aging for all samples. For samples of 5 wt% Pd, the response to CO was decreased by a factor of 4 after 20 days of aging. Fortunately, some rather mild heat treatments will quite effectively reactivate those aged samples. Heat treatment at 150 °C for 15 min in air tripled the response to CO for a 20 days-aged sample of 5 wt% Pd. It is proposed that the deposition of impurity gases in air on Pd in Pd-SnO2composite nanoceramics has resulted in the observed aging, while their desorption from Pd through mild heat treatments leads to the reactivation. More studies on aging and reactivation of room-temperature gas sensitive MOSs should be conducted to achieve high long-term stability for room-temperature MOS gas sensors.Keywords:CO;sensors;SnO2;aging;heat treatment;recover
研究领域:
材料科学
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传感器技术
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产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Yulan Tang,Dongrui Zhou,Xiankun Zhang,Xianyuan Sun,Zesheng Sheng,Ting Li
Laccase–Cu3BTC2 was synthesized from laccase and Cu3BTC2 metal–organic skeleton materials and doped with the highly hydrophilic amphiphilic polymer polyvinylidene fluoride-graft-poly(ethylene glycol) methyl ether methacrylate (PVDF-g-PEGMA) as a bimodifier in the casting solution using in situ synthesis to prepare high-flux poly(vinylidene fluoride) (PVDF) membranes. Due to the high hydrophilicity of PVDF-g-PEGMA and laccase–Cu3BTC2, the PVDF-modified membranes were more hydrophilic; the water contact angle decreased from 93.45° to 79.46°. It exhibited optimal performance when its mass fraction relative to PVDF was 8.0%. Pure water flux and the sodium alginate retention rate reached 1975.61 L/(m2·h) and 87.79%, respectively, and the flux recovery and reversible and irreversible contamination ratio were 84.64%, 71.07%, and 15.36%, respectively, substantially enhancing the pollution resistance of the PVDF membrane.
研究领域:
材料科学
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环境工程
·
生物技术
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DOI
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Yan-Wei Liu,Ying Zhou,Guo-Qing Huang,Li-Ping Guo,Xiao-Dan Li,Jun-Xia Xiao
Coacervation of the lipase from Aspergillus oryzae (AOL) with chitosan was a feasible way to fabricate lipase-loaded particles and the optimum conditions were phase separation pH 5.5, chitosan to AOL mass ratio 1:5, and temperature 25 °C in the absence of NaCl, which conferred an AOL loading efficiency of up to 95.48% and activity recovery of 69.60%. The AOL-chitosan coacervates were highly porous and more susceptible to weight loss upon heating. Coacervation with chitosan increased the activity of AOL and shifted its optimum pH from 7.0 to 6.0, but exerted no effect on its optimum temperature (45 °C). Thermal deactivation kinetics analysis revealed that the coacervated AOL was more thermal stable, while the Michaelis-Menten kinetics analysis indicated that coacervation with chitosan increased the V max of AOL by 2.4 folds, but decreased its substrate affinity by 3.6 folds. Hence, the AOL-chitosan coacervates are potential in the construction of Pickering emulsion-based lipase catalysis systems.
研究领域:
生物化学
·
酶工程
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DOI
高影响因子
Current Analytical Chemistry
·
2020
·Vol. 16
·期 6
·744-752
·
IF 1.365
Luo Kuan,Jiang Xinyu
Background: Diabetes Mellitus (DM) is a major public metabolic disease that influences 366 million people in the world in 2011, and this number is predicted to rise to 552 million in 2030. DM is clinically diagnosed by a fasting blood glucose that is equal or greater than 7 mM. Therefore,
the development of effective glucose biosensor has attracted extensive attention worldwide. Fluorescence- based strategies have sparked tremendous interest due to their rapid response, facile operation, and excellent sensitivity. Many fluorescent compounds have been employed for precise analysis
of glucose, including quantum dots, noble metal nanoclusters, up-converting nanoparticles, organic dyes, and composite fluorescent microspheres. Silicon dot as promising quantum dots materials have received extensive attention, owing to their distinct advantages such as biocompatibility, low
toxicity and high photostability. Methods: MnO2 nanosheets on the Si nanoparticles (NPs) surface serve as a quencher. Si NPs fluorescence can make a recovery by the addition of H2O2, which can reduce MnO2 to Mn2+, and the glucose can thus be monitored based on the enzymatic conversion
of glucose by glucose oxidase to generate H2O2. Therefore, the glucose concentration can be derived by recording the fluorescence recovery spectra of the Si NPs. Results: This probe enabled selective detection of glucose with a linear range of 1-100 μg/mL and a limit of detection of
0.98 μg/mL. Compared with the commercial glucometer, this method showed favorable results and convincing reliability. Conclusion: We have developed a novel method based on MnO2 -nanosheet-modified Si NPs for rapid monitoring of blood glucose levels. By combining the highly sensitive
H2O2/MnO2 reaction with the excellent photostability of Si NPs, a highly sensitive, selective, and cost-efficient sensing approach for glucose detection has been designed and applied to monitor glucose levels in human serum with satisfactory results.
研究领域:
生物医学工程
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分析化学
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糖尿病研究
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DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2020
·
IF 3.306
Haochi Liu,Jie Ding,Ligang Chen,Lan Ding
A novel approach was proposed to prepare carbon dots (CDs) by acid carbonization and hydrothermal treatment of pork rib bones from food waste. The synthesized animal waste biomass CDs have the merits of eco-friendly, superior fluorescence properties and biocompatibility. The fluorescence of animal waste biomass CDs could be quenched efficiently by dithizone due to the coordination effect. With the addition of dimethoate, the dithizone ligands at CDs are replaced by hydrolysates, and hence the fluorescence is recovered. Thus, a sensing platform was constructed based on the coordination-originated fluorescence of animal waste biomass CDs which can sensitively and selectively detect dimethoate due to a simple displacement mechanism. Upon optimal conditions, the detection limit of dimethoate is 0.064 μM. The linear ranges were obtained in a range of 0.15 μM–5.0 μM. The method is rapid, convenient and environmentally acceptable that can directly detect dimethoate in water samples with recoveries of 93 %–105 %, and the relative standard deviations (RSDs) were 2 %–6 %, respectively. This simple strategy can be used to develop the fluorescence recovery sensors for chemical detection.
研究领域:
分析化学
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环境科学
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食品科学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2021
·Vol. 28
·期 9
·1-12
·
IF 3.097
Meng Haitao,Liang Haiou,Xu Tong,Bai Jie,Li Chunping
To achieve the effluent standards or water purification, many water-treatment methods including membrane separation have been applied to separate the oily contaminations and clean water. However, most of the membranes displayed a low separation efficiency or poor reusability due to the functional group loss or their surface adhesion of contaminations including oil and biofoulings. Thus, in this work, a hydrophilic crosslinked PVP membrane was facilely prepared via the electrospinning and crosslinking. Crosslinking solves the problem of loss of hydrophilic components in the separation process, and the cPVP-PAN membrane has high hydrophilicity and excellent pollution resistance. The cPVP-PAN membrane showed a high separation flux (20,610 L m −2 h −1 bar −1 ) and an excellent separation efficiency (above 97%) for the oil–water mixtures. At the same time, the membrane has good separation capacities for different oil–water mixtures. Importantly, it shows high separation flux of O/W emulsion (569 L m −2 h −1 ) only under gravity conditions and a low flux-loss (8.08% after 10-cycle filtration). Furthermore, the membrane could effectively resist the contamination of BSA protein and oil, the flux recovery rates (FRRs) were more than 87.6%. Such membrane shows a broad application prospect in the complex water environmental remediation.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
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2022
·
IF 6.056
Tianqi Cui,Yuxue Sun,Yue Wu,Jiarong Wang,Yangyue Ding,Jianjun Cheng,Mingruo Guo
Novel gelatin/dialdehyde starch (GDS) hydrogels based on gelatin were prepared using dialdehyde starch as a macromolecular crosslinking agent. Fourier transform infrared spectroscopy , Raman spectroscopy , and X-ray diffraction showed that the dynamic hydrogel network was formed by covalent imine bonds and hydrogen bonds between dialdehyde starch and gelatin. The synergistic physical and chemical cross-linking endowed the hydrogels with excellent mechanical properties (maximum compressive stress was 0.55 MPa), fatigue resistance (they maintained their shape after ten compression cycles), toughness (54.6 kN/m 2 ), and self-recoverability of the polymeric network. In the rheological tests, all the storage modulus were higher than loss modulus, indicating that they are elastic gels and not viscous sols. The polymer network of GDS hydrogels could recover rapidly when subjected to oscillating shear strain. In addition, with increasing dialdehyde starch concentration, the hydrogels had higher swelling stability and a denser microstructure. Given these excellent properties, the hydrogels have potential application prospects as cell culture scaffolds and carriers of bioactive substance.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Wenjing Tang,Yunyi Meng,Bin Yang,Dongyu He,Yan Li,Bojun Li,Zheming Shi,Changwei Zhao
Nanofiltration (NF) process has become one of the most promising technologies to remove micro-organic combined water pollution . Developing a NF membrane material with efficient separation for perfluorooctanoic acid (PFOA) combined pollution is highly desired, this manuscript targets this unmet need specifically. In this work, hydrophilic SiO 2 nanoparticles with various contents blended with carboxylic multiwalled carbon nanotube were used to modify poly (m-phenylene isophthal amide) (SiO 2 /CMWCNT/PMIA) hollow fiber NF membrane. The modified membrane with 0.1 wt% SiO 2 doping exhibits way better fouling resistance with irreversible fouling ratio decreased dramatically from 18.7% to 2.3%, and the recovery rate of water flux increases significantly from 81.2% to 97.7%. The separation experiment results had confirmed that the modified membrane could improve the rejection from 97.2% to 98.6% for perfluorooctanoic acid (PFOA) and its combined pollution with bovine serum albumin (BSA). It is clear that this reported SiO 2 /CMWCNT/PMIA hollow fiber NF membrane potentially could be applied in water treatment . This research also provides a theoretical basis for efficiently removal of PFOA and its combined pollution by NF membrane.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Jincheng Mao,Quanhang Wang,Jinzhou Zhao,Heng Zhang,Jinxing Xue,Yang Zhang,Tao Xu,Xiaojiang Yang,Chong Lin,Zigao Huang,Jinhua Mao,MingJin Cai
In recent years, polymers used as thickeners in fracturing fluids tend to pursue a higher molecular weight for better thickening performance. However, these polymers experience mechanical degradation under high shear conditions. To improve the adaptability of polymer fracturing fluids to mechanical shear, a novel hydrophobically associating polymer (HALMP) was developed by enhancing the hydrophobic association action (to improve viscosity and elasticity) while decreasing the molecular weight (to avoid shear degradation and ensure solubility) and characterized by 1H NMR and infrared tests. The calculated molecular weight of HALMP from intrinsic viscosity is 150 × 104 g/mol, and it was concluded that there is strong hydrophobic association in polymer solution from the microscopic structure and macroscopic properties by pyrene fluorescence probe technique, viscoelasticity, and thixotropy tests. Meanwhile, the critical association concentration and the aggregation pattern of polymer molecules in solution were investigated. The shear recovery tests and scanning electron microscopy revealed that the polymer solution contains a dynamic physical crosslinking network that can be “healed” by the intermolecular hydrophobic association action after being sheared. The results also show that HALMP exhibits excellent thickening performance even at a high shear rate. These findings not only demonstrate the feasibility of polymer fracturing fluids with strong association and low molecular weight but also offer alternative methods to prepare high-functional polymers.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Chemosensors
·
2022
·Vol. 10
·期 11
·464
·
IF 4.229
Zhaonan Hou,Zhiyan Ma,Xin Guan,Hongran Zhao,Sen Liu,Teng Fei,Tong Zhang
Humidity sensors with high sensitivity and fast response characteristics are of great interest for researchers. In this work, capacitive humidity sensors were fabricated using ionic liquid/cellulose nanofibers (CNFs) as the composited sensing film. The porous CNFs are beneficial for preparing sensing films via a solution process, and the ionic liquid could be uniformly dispersed in the films. The humidity-sensing performance of the as-prepared sensors was investigated. The optimized sensor showed a high response (27.95 pF/% RH) in a wide humidity range (11–95% RH) and a fast response speed in the adsorption process (the recovery time was only ~1 s). The high response of the sensors was attributed to the polarization at the interface between the electrolyte and the metal electrode, while the fast recovery was due to the rapid desorption of water molecules on the sensing films. Finally, the application of the obtained sensors in human breath monitoring was explored.Keywords:humidity sensor;high sensitivity;fast recovery;breath monitoring
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Zhengdong Feng,Wei Huang,Fei Lv,Wei Li
Shape memory polymers (SMPs) are pivotal for applications in soft robotics, biomedical devices, and flexible electronics. However, their reliance on external stimuli for activation and the difficulty of precisely programming recovery dynamics remain significant limitations. Autonomous SMPs with delayed recovery offer a promising alternative, yet facile control of recovery onset and duration is still difficult to attain. Here, a semi-interpenetrating network (semi-IPN) hydrogel composed of poly(acrylic acid) and silk fibroin (PAA-SF) is presented, fabricated via a facile one-step UV polymerization. By modulating the SF content within the PAA network, the hydrogel exhibits tunable shape recovery kinetics across multiple programming environments, including organic solvents, air, and water, enabling spatiotemporal control over shape restoration. Moreover, the hydrogels show significantly enhanced mechanical properties and strong adhesion compared to neat PAA hydrogels. Benefiting from these combined properties and excellent cytocompatibility, demonstrating two proof-of-concept devices: a smart four-jaw gripper capable of retrieving objects in confined spaces, and a stiffness-switchable needle that reversibly transitions between soft and rigid states. This work not only introduces a robust and multifunctional shape memory hydrogel but also provides a versatile platform for designing stimulus-free, time-programmable soft actuators for biomedical and robotic applications.
研究领域:
材料科学
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生物医学工程
·
软体机器人
·
高分子科学
·
功能水凝胶
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产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2020
·Vol. 298
·期 12
·1715-1727
·
IF 1.536
Lu Yifei,Shao Jia,Wang Sui,Guo Zhiyong,Hu Yufang
The development of tenacity photoluminescent (PL) hydrogels is very great significance to promote the application of optical technology in hydrogel. Herein, we report a high-toughness PL hydrogel that combines synthetic hydrophilic lanthanide complex (LCs) and tannic acid (TA) with polyvinyl alcohol (PVA) by frozen-thawing. The resulting hydrogel has high mechanical strength (1194.46-kPa tensile strength, 1266.17-kJ m −3 toughness energy, 1915.58-kPa compressive strength, and 269.79-kJ m −3 energy dissipation at 80% compression), excellent self-recover and anti-fatigue performance, good photoluminescence, and switchable functions under UV light, showing red (254 nm) and green (365 nm), respectively. The design strategy offers a new approach for the preparation of multifunctional and tenacity PL hydrogels.
研究领域:
材料科学
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高分子化学
·
光学材料
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）