JOURNAL OF MATERIALS SCIENCE
·
2023
·
IF 4.5
Gao Nengwen,Liu Jing,Wang Xiaoli,Zhang Yu
Lipases are widely used in industry. Free lipases are difficult to recover and have poor stability under operational conditions. Herein, lipases are immobilized onto the methyltrimethoxysilane (MTMS)-modified ceramic membranes (~ 5 nm) with reverse filtration method, and further cross-linking by glutaraldehyde (GA) is used to improve the lipase stability. FTIR and XPS analyses demonstrate the successful immobilization of lipase. The immobilized lipases are used to hydrolyze glycerol triacetate (GT) to fatty acids and glycerol. Under the optimal immobilization conditions (MTMS concentration 0.1 M, lipase immobilization time 80 min, lipase concentration 3 mg/mL, and GA concentration 2%), the loading of lipases reaches 0.24 mg/g. Under the optimal operational conditions (temperature 45 °C, pH 7, pressure 0.2 MPa, GT concentration 0.05 M), the immobilized lipases have the highest catalytic activity of 25 U/mg. Moreover, the thermal and pH stabilities of immobilized lipases are found to be higher than those of the free lipases. In the long-term runs, the immobilized lipases still have 64% of the initial activity after 7 cycles, indicating good reusability. This paper provides a simple process for immobilizing lipase on ceramic membranes. The immobilized lipases have better stability at high temperature and basic environments (pH 7–9), which would have broad applications in lipase-catalyzed reactions. Graphical Abstract
研究领域:
生物化学
·
酶工程
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DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2020
·Vol. 27
·期 4
·1241-1251
·
IF 2.183
Huang Siqi,Wu Xiaoxu,Li Zhi,Shi Long,Zhang Yan,Liu Qiong
In this work, monolithic silica aerogels were prepared in pure water within 4 h by using MTMS as the precursor under ambient pressure drying (APD). The effects of the volume ratio of H 2 O/MTMS, CTAB content and NH 3 ·H 2 O concentration on the properties of MTMS-based aerogels (MSA) were investigated experimentally. The realization of the rapid synthesis of MSA under APD is attributed to getting rid of the aging process, solvent exchange and surface modification. It demonstrates that the microstructure of MSA is comprised of coralloid branches. Furthermore, the greater volume ratio of H 2 O /MTMS, larger CTAB content and smaller NH 3 ·H 2 O concentration cause relatively slimmer coralloid branches, smaller pores and weakened connectivity of skeletons. It also finds that the MSA with a greater volume ratio of H 2 O/MTMS presents larger Young’s modulus and smaller compressive stress, which is because of the correspondingly different microstructures. The as-prepared MSA shows a low density of 0.064 g/cm 3 and a contact angle as high as 143.4°, which provides their potentials for some engineering applications.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2020
·Vol. 22
·期 8
·1-15
·
IF 2.132
Wu Xiaoxu,Huang Siqi,Zhang Yan,Shi Long,Luo Yan,Deng Xi,Liu Qiong,Li Zhi
Considering the low thermal stability and high flammability of polyurethane sponge (PUS) and the poor mechanical performance of methyltrimethoxysilane (MTMS) aerogels, their combination for improvement of characteristics was investigated. The density of prepared polyurethane sponge/MTMS aerogel (PUSMA) composites increased exponentially between 0.032 and 0.13 g/cm 3 with the MTMS aerogel content rising, and the thermal conductivity increased linearly between 36.5 and 44.3 mW/(m K). The good hydrophobicity was maintained with a contact angle up to 145.0°. Despite the combination being physical effects, the PUSMA composite presented improved mechanical properties with better integrality and increased elastic modulus. Thermogravimetric analyses suggested that the synergistic effect in the combination improved the thermal stability. The flame combustion probability and the peak heat release rate with flame combustion decreased significantly, implying enhanced flame retardancy of the PUSMA composite. This study from the perspective of composites provides new insight into the development of new high-efficiency aerogel-based thermal insulation materials.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2024
·
IF 2.3
Liu Qiong,Deng Siyuan,Wang Ziyi,Xie Linlin,Wang Guichao,Chen Zhenkui,Wu Xiaoxu,Li Zhi
Compared with nanoscale aerogels, the thermal conductivity of MTMS silica aerogel (MSA) is relatively large due to its micron-sized pore size, which hinders its popularization in the field of thermal insulation. In this study, the MSA samples with relatively low thermal conductivity (33.7 mW/m/K) and density (0.071 g/cm 3 ) were prepared. Then, the theoretical mathematical models of thermal conductivity were discussed and selected. The three-dimensional model based on X-ray microscopic CT slices was reconstructed for their micrometer-scale structure and based on this physical reconstruction model, finite element numerical simulations were carried out. The two-hierarchy structure of MSA was found during scanning electron microscopy, and the stepwise prediction of its effective thermal conductivity was carried out using the equivalence method. The mathematical model applicable to MSA was also modified to propose hierarchically theoretical calculation (HTC) for thermal conductivity. The feasibility and accuracy of the mathematical modeling method were verified by the finite element numerical simulation method based on the high-reduction three-dimensional reconstruction model, and the prediction results of the two were in good agreement with the experimental test data, of which the error was within 5%. Graphical Abstract
研究领域:
材料科学
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热物理学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2023
·Vol. 30
·期 6
·1-13
·
IF 2.8
Su Hao,Yang Jin
Using 3-aminopropyltriethoxysilane (KH550), γ-glycidyloxypropyltrimethoxysilane (KH560) and silica with different particle sizes as raw materials, the grafting reaction through layer-by-layer assembly strawberry-like silica particles with multi-scale effects were prepared, and their structures were characterized by infrared spectroscopy (FT-IR), hydrogen nuclear magnetic resonance (NMR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and other testing methods. Then it was physically blended with laboratory-made water-based epoxy resin WEP, and the coating with superhydrophobic properties was prepared by the low surface energy modification of methyltrimethoxysilane (MTMS). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to characterize the blending stability and heat resistance of the coating, and to analyze its morphological characteristics with scanning electron microscopy (SEM), and to analyze its abrasion resistance by measuring the change in the surface contact angle of the coating under certain conditions, Chemical resistance. The results showed that the prepared strawberry-like silica particles reached the expected structure, and formed Pickering emulsion similar to oil-in-water after blending with WEP, which was a stable emulsion system of solid particles. At the same time, due to the introduction of strawberry-like silica particles and the low surface energy modification of MTMS, the modified WEP has superhydrophobic properties, as well as excellent abrasion resistance, corrosion resistance and self-cleaning effect.
研究领域:
材料科学
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表面化学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Chen Yan,Jing Luo,Caoxing Huang,Liang Liu,Shijing Sun,Xin Zhou
Cellulose-based porous materials are promising for various fields and preferred for sustainable development. However, the low mechanical properties and high hydrophilicity of cellulose-based xerogels had a direct influence on their application in oil absorption. To address the challenge, an environmentally friendly and economical method for synthesizing MTMS/C0.2-TOCN0.9 xerogels with high hydrophobicity and excellent mechanical strength was successfully established. In this work, shape-recoverable using nanocellulose (TOCN)-based xerogels with porous structure (porosity of 91.5–98.7 %), as well as excellent hydrophobic properties were prepared by TOCN-stabilized wet foams with physical crosslinking, ice crystal-induced phase separation and MTMS modification through simple air-drying instead of the traditional freeze-drying. At the optimized ingredients of TOCN and crosslinker (Ca 2+ ), the xerogel (MTMS/C0.2-TOCN0.9) exhibited superior compressive performance (approximately 35 KPa) and exceptional structural stability after 50 cycles at a compression deflection of 60 %, which was still maintained at 71.5 % of the original stress. Moreover, the MTMS/C0.2-TOCN0.9 xerogel achieved stable superhydrophobicity (128.3°) and excellent oil absorption capacity (59.6 g/g), rendering it a desirable adsorbent for oil spill cleaning. Compared to the pseudo-first-order model, the pseudo-secondary model had higher validity in oil absorption kinetic theories. The MTMS/C0.2-TOCN0.9 xerogel was recyclable and nontoxic, which has the potential to promote environmental applications.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
Coatings
·
2025
·Vol. 15
·期 7
·769
·
IF 2.8
Lu Cao,Zhutao Ding,Qi Chen,Yefeng Ji,Ying Xiong,Yun Gao,Zhongyan Huo
With the rapid development of marine renewable energy, especially offshore photovoltaic systems, the problem of biofouling of photovoltaic equipment in the marine environment has become increasingly prominent. The attachment of marine organisms such as algae will significantly affect the photoelectric conversion efficiency of photovoltaic panels, thereby reducing the stability and economy of the system. In this study, a composite siloxane coating was designed and prepared. Methyltrimethoxysilane (MTMS) was used as the organosilicon component. The negative potential of the coating was significantly enhanced by incorporating hexagonal boron nitride nanosheets (h-BNNS). This negative potential and the negative charge on the surface of marine organisms, especially algae, would produce electrostatic repulsion, which can effectively reduce the attachment of organisms. The results show that the prepared coating exhibits excellent performance in anti-biofouling, adhesion, chemical stability, transparency, and self-cleaning properties. The transparency of the coating reached 92.7%. After immersion with Chlorella for 28 days, the coverage percentage on the coating surface was only 0.98%, while the coverage percentage on the blank sample was 23.25%. The corrosion resistance and salt resistance of the coating also ensure its stability in complex marine environments, and it has broad application prospects.
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高影响因子
Gels
·
2023
·Vol. 9
·期 4
·317
·
IF 4.6
Linlin Xie,Xiaoxu Wu,Guichao Wang,Yury M. Shulga,Qiong Liu,Ming Li,Zhi Li
To address the leakage issue of paraffin phase-change materials in thermal management, a monolithic MTMS-based silica aerogel (MSA) is employed to encapsulate paraffin through a facile impregnation process. We find that the paraffin and MSA form a physical combination, with little interaction occurring between them. The prepared no-leakage paraffin/MSA composites have a density of 0.70 g/cm3and exhibit good mechanical properties and nice hydrophobicity, with a contact angle of 122°. Furthermore, the average latent heat of the paraffin/MSA composites is found to reach up to 209.3 J/g, about 85% of the pure paraffin’s latent heat, which is significantly larger than other paraffin/silica aerogel phase-change composite materials. The thermal conductivity of the paraffin/MSA remains almost the same as that of the pure paraffin (~250 mW/m/K), without any heat transfer interference from the MSA skeletons. All these results indicate that MSA can effectively serve as a carrier material for encapsulating paraffin, which is beneficial for expanding the applications of MSAs in thermal management and energy storage.
研究领域:
材料科学
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能源工程
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产品关联
DOI
PubMed
高影响因子
Gels
·
2025
·Vol. 11
·期 11
·906
·
IF 5.3
Yong Ren,Huanlin Zhang,Xingwei Jiang,Miao Liu,Zhi Li
With the continuous increase in global energy consumption and the escalating severity of climate change, the development of high-performance thermal insulation materials is crucial for reducing energy waste and carbon emissions. In this work, a facile method was proposed to prepare thermal-insulating glass fiber wool/methyltrimethoxysilane aerogel (GFWA) composites through vacuum-assisted impregnation. The obtained results indicated that GFWA composites exhibited excellent thermal insulation and hydrophobic properties, with GFWA-30 containing 30 wt.% glass fiber wool having a thermal conductivity of 35.3 mW/m·K and a water contact angle of 125.8°. Additionally, the Young’s modulus of this composite was 21.2% higher than that of MTMS aerogel. In terms of thermal safety performance, compared to methyltrimethoxysilane aerogel, the GFWA-30 composite showed reductions of 21.6%, 18.8%, and 27.95% in peak heat release rate, total heat release, and gross calorific value, respectively. This study offers a simple and feasible approach to fabricating high-performance thermal insulation materials, which display huge potential for widespread application in the fields of building insulation and other fields with thermal insulation requirements.
研究领域:
材料科学
·
热工工程
·
能源效率
·
聚合物复合材料
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2021
·Vol. 23
·期 12
·1-11
·
IF 2.253
Wang Xiaowu,Deng Xi,Wu Liling,Deng Yunmeng,Liu Qiong,Li Ming,Li Zhi
To overcome the poor mechanical performance of methyltrimethoxysilane (MTMS) aerogels and the low thermal stability of polyvinyl alcohol (PVA), the PVA/MTMS aerogel composites (PMAC) were successfully prepared through a facile impregnation process. It finds that the PVA concentration has a great influence on the physicochemical properties of the PMAC, which has been investigated in detail. It further turns out that the density (0.081 ~ 0.152 g/cm 3 ) increases linearly along with the PVA concentration, while the thermal conductivity (32.9 ~ 51.7 mW/m/K) increases monotonously first and then keeps almost unchanged. The hydrophilicity of PMAC can be tailored by adjusting the PVA concentration. Compared with the pure MTMS aerogel and PVA, the thermal analysis reveals that the PMAC shows an improved thermal stability. Although the physical combination is verified between the MTMS aerogel and PVA, the mechanical performance of the PMAC is still significantly enhanced with the Young’s modulus and compressive strength reaching up to 20.35 MPa and 970.33 kPa, respectively. All these results suggest that the introduction of PVA into MTMS aerogel is feasible and effective for acquiring better performance for the aerogel composites, which contributes to extending their potential applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2022
·Vol. 102
·期 2
·400-411
·
IF 2.606
Yue Wenda,Liang Jun,Wang Honghai,Zhang Yu,Li Chunli,Su Weiyi
In the entrapment of enzymes by sol-gel method, the special procedures for obtaining the unique structure of xerogel are sometimes destructive to enzymes, while the internal structure of xerogels is easily broken. To solve the above problems, we present an economical, bio-friendly procedure for the entrapment of Candida antarctica lipase B in silica xerogel. In this procedure, an encapsulation-structured enzyme-carrying silica xerogel was produced by controlling the evaporation rate of the solvent at ambient pressure during drying, while tetramethoxysilane and methyltrimethoxysilane were used as the co-precursors. The xerogel synthesis was modified and optimized for improving the stability and reusability of the enzyme, while the xerogel characteristic structure was preserved. Moreover, the effects of the co-precursors amount on the mechanical strength, pore structure, hydrophobicity, enzyme loading, and enzyme stability of the enzyme-carrying silica xerogels were systematically investigated. And the best performance was observed at the co-precursors content of 30.28 wt%. Finally, the catalytic performance of the enzyme-carrying silica xerogels on the transesterification of n -butanol with ethyl acetate was demonstrated.
Graphical abstract
研究领域:
生物化学
·
材料科学
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2026
·
IF 4.5
Falong Shan,Jingru Dou,Yinghou Li,Yaqi Xu,Guanghui Chen,Pan Zhang,Fei Gao,Jipeng Dong
To address the challenge that Cu + active species in developed Cu + -based adsorbents tend to oxidize to Cu 2+ in humid air, thereby losing their adsorption performance for carbon monoxide, in this study, methyltrimethoxysilane (MTMS) was employed as a hydrophobic modifier to modify the Cu + -based CO adsorbent. The hydrophobically modified Cu + -based CO adsorbent effectively shields the Cu + active species from water, thereby significantly inhibiting their oxidative deactivation. The successful grafting of MTMS onto the ultra-stable Y-type zeolite (USY) support was confirmed, thus markedly enhancing the hydrophobicity of the resulting Cu + -based CO adsorbent. The optimized adsorbent, CuCl(4)@USY-MTMS(24%), exhibits a high CO adsorption capacity of 2.61 mmol/g, coupled with high adsorption selectivity for CO/CO 2 and CO/N 2 . Moreover, the MTMS-modified hydrophobic CuCl(4)@USY-MTMS(24%) adsorbent exhibits significantly enhanced oxidation resistance compared to its unmodified counterpart, after aging in 70% relative humidity air for 24 h, it retains 79% of the CO adsorption capacity of pristine adsorbent, far exceeding the 47% retention of the unmodified version. This remarkable performance confirms that the hydrophobically modified adsorbent achieves stable CO separation.
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DOI
高影响因子
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