INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2016
·
IF 3.138
Gang Fang,Honggao Chen,Yunpeng Zhang,Anqing Chen
Fe 3 O 4 magnetic nanometer particles (MNPS) with a diameter of 30–40 nm and coated by ammoniated silicon dioxides were developed by sol–gel method. The X-ray diffraction (XRD) pattern indicates that the Fe 3 O 4 is wrapped in the amorphous SiO 2 , and the Fourier-transform infrared spectroscopy (FT-IR) analysis confirmed the NH 2 group had been successfully introduced onto the surface of Fe 3 O 4 @SiO 2 nanoparticles. The main factors related to the immobilization process of pectinase onto the magnetic support were optimized by multi-factor orthogonal experiments, and the recommended combination is that 3% glutaraldehyde (coupling agent), pH = 8.0, 50 °C, and cross-linking time 8 h. Scanning electron microscope (SEM) and FT-IR analyses confirmed that the pectinase had been immobilized onto the surface of the amino modified nanoparticles. The storage stability and reusability of the pectinase were enhanced by the immobilization that 64.4% of the total starting activity was retrieved after 7 recycling batches and only about 21.1% of the total activity was lost after 30-day storage. For the application of the immobilized pectinase, the optimal pH and temperature were 8.5 and 55 °C, respectively.
研究领域:
生物化学
·
纳米生物学
·
酶工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2016
·Vol. 141
·期 11
·3421-3427
·
IF 4.033
Dongpo Xu,Mingxia Gao,Chunhui Deng,Xiangmin Zhang
Ti4+ immobilized SiO2 graphene-like multilayer nanosheets were designed and synthesized for the ultrasensitive enrichment of phosphopeptides with the detection limit of 1.0 pg μL−1 (4 × 10−17 mol μL−1). The enrichment selectivity of the nanosheets was evaluated by capturing phosphopeptides from a peptide mixture of bovine β-casein (β-casein) and bovine serum albumin (BSA) with the molar ratio of 1 : 1000 (1.7 × 10−12 mol of β-casein and 1.7 × 10−9 mol of BSA in 100 μL).
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Membranes
·
2018
·Vol. 8
·期 4
·89
·
IF 0
Qin Liu,Xing Wu,Kaisong Zhang
To improve the filtration performance and properties of organic solvent nanofiltration (OSN) membranes, we firstly introduce nanoporous silica (SiO2) particles into the polyamide (PA) active layer of polysulfone (PSf) membrane via an interfacial polymerization process. Results from the study revealed that introduction of SiO2influenced the properties of PSf/PA-SiO2composite membranes by changing the surface roughness and hydrophilicity. Moreover, results also indicated that nanoporous SiO2modified membranes showed an improved performance of alcohols solvent permeance. The PSf/PA-SiO2composite membrane modified by 0.025 wt % of SiO2reached a permeance of 3.29 L m−2h−1bar−1for methanol and 0.42 L m−2h−1bar−1for ethanol, which were 20.0% and 13.5% higher than the control PSf membrane (permeance of 2.74 L m−2h−1bar−1for methanol and 0.37 L m−2h−1bar−1for ethanol). Conclusively, we demonstrated that the increase of membrane hydrophilicity and roughness were major factors contributing to the improved alcohols solvent permeance of the membranes.Keywords:silica;polysulfone;composite membrane;polyamide
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
·
2013
·
IF 1.266
Chundong Li,M.M. Mikhailov,V.V. Neshchimenko
The effects of proton and electron ( E = 100 keV, F = 5 × 10 15 сm −2 ) exposure on the reflective spectra of SiO 2 micro- and nanopowders in wavelength range from 250 to 2500 nm have been investigated. It has been established that the reflectance and radiation stability of nanopowders is less than that of micropowders. This effect is caused by the high concentration of radiation defects, which act as surface absorption centers ( E s ′ centers) near the energies 5.47 and 4.45 eV, and peroxide silicon defects ( Si O O Si ) near the energy 3.84 eV.
研究领域:
材料科学
·
辐射物理学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2023
·
IF 5.4
Weizhou Li,Quanzhi Chen,Deli Shen,Ruixia Yang,Xiuhai Zhang
In order to decrease defects and improve protective performance, micro-arc oxidation (MAO) coating was modified by adding SiO 2 particles to form a composite coating on TA2 alloy via laser treatment. The microstructural morphology, phase structure, cohesive strength and corrosion resistance of the composite coatings were investigated and analyzed by using SEM, XRD , thermal cycle, and electrochemical testing, respectively. The results showed that SiO 2 particles were firstly adsorbed onto the MAO surface with the aid of ultrasonic treatment and then sealed micro-pores of the MAO coating after laser treatment. The composite coating mainly consisted of R-TiO 2 , A-TiO 2 and SiO 2 phases and exhibited a dense multilayer structure with a rich Si element in the outer layer. After subjecting the coatings to 300 thermal cycles, clacking or marked spalling zones could not be observed in the composite coating; nevertheless, an obvious destruction appeared in the single MAO coating without SiO 2 particles. The corrosion potential ( E corr ) and pitting potentials ( E pit ) of the composite coating were −0.303 V and 1.765 V compared to that of −0.682 V and 1.401 V for the single MAO coating. Additionally, the corrosion rate decreased to 1.40 × 10 −4 A·cm −2 with the highest resistance (76,788.67 Ω·cm 2 ) from2.19 × 10 −4 A·cm −2 , indicating a stronger corrosion resistance in the composite coating. The results of simulation from Comsol Multiphysics demonstrated that a laser power as 80 W was appropriate for melting SiO 2 particles into the MAO coating to form a dense and cohesive composite coating.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Lihao Liu,Zhaofeng Chen,Lixia Yang,Mengmeng Yang,Qiong Wu,Mingxiao Shi,Bin Hou
The fiber/aerogel material prepared by the traditional method of sol-gel has a serious powder shedding phenomenon, and has serious environmental pollution and health hazards. In this study, an environmentally friendly porous sound absorption material with a cage-like structure, which used flexible ultrafine glass/quartz hybrid fibers (HFs) as the carrier and SiO 2 aerogel as the pore filler, was produced using the wet manufacturing process. The addition of aerogel enhanced the internal reflection of sound waves, reduced the propagation speed, increased the acoustic energy loss and improved the sound absorption coefficient (SAC). The noise reduction coefficient (NRC) reaches 0.49 in the range of 250–6300 Hz. The obtained composite presented a low density (73.5 mg/cm 3 ) and heat resistance up to 500 °C.
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2023
·
IF 9.9
Tong Zongwei,Yan Xiangjie,Wang Yuexiang,Li Kexun,Ma Weihai
Increasing porosity is one of the most direct ways to improve the thermal insulation and dielectric properties of materials. Until now, many wet methods for preparing Si 3 N 4 ceramic foams usually face the problems of complex rheology, long period, and expensive cost, and the reported pore sizes of Si 3 N 4 ceramic foams are typically micron-grade, resulting in a lack of competitiveness in thermal insulation and wave-transparent applications. In this paper, the Si 3 N 4 @SiO 2 ceramic foams were prepared using an efficient dry-method, which combined three processes of low temperature chemical vapor deposition (LTCVD), template, and isostatic pressing. The method has the advantages of simple operation and short preparation period, and can realize near-net size molding and mass production. In addition, the evolution mechanisms of honeycomb microstructure and composition of Si 3 N 4 @SiO 2 ceramic foam during sintering were studied by chemical reaction thermodynamics. The as-prepared Si 3 N 4 @SiO 2 ceramic foam possesses low density (0.377 g·cm −3 ), high compressive strength (7.5 MPa), low thermal conductivity (0.0808 W·m −1 ·K −1 ), and excellent dielectric properties ( ε < 1.32, tan δ < 0.009) in the frequency range of 8–18 GHz, and its maximum working temperature in air can reach up to 1100 °C. It will be recommended to be applied in the interlayer of Si 3 N 4 ceramic radome to improve its thermal insulation and electromagnetic wave transparency performances.
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 37
·25780-25788
·
IF 3.3
Runna He,Shuangqing Sun,Jianpeng Cui,Mingshuo Chi,Zhikun Wang,Songqing Hu
In recent years, Pickering emulsifiers have been widely used in various production fields due to their excellent structural stability, biocompatibility and environmental friendliness. For some applications, it is required that the emulsifier can quickly respond to environmental stimuli and control the transition between stable and unstable emulsions. In this paper, we report a novel composite Pickering emulsifier with Fe3O4 as the core and magnetic response recognition body, silica as the intermediate protective layer, and chitosan (CS) of different molecular weights to endow solid particles with surface activity and pH-responsive properties. This emulsifier can stabilize the emulsion in the emulsion system with deionized water as the aqueous phase and liquid paraffin as the oil phase and can control the demulsification of the formed emulsion under the dual pH/magnetic stimulation. The experimental results show that Fe3O4@SiO2@CS has good paramagnetism and pH responsiveness. The particle size of the composite emulsifier nanoparticles is between 90 nm and 120 nm, and the best stabilizing effect of the emulsion is achieved when the dosage is 0.5 wt%. In the pH range of 3–11, the emulsifier can rapidly demulsify a stable paraffin oil–water emulsion system under the action of a magnetic field of strength 0.4 T. The pH response of the emulsifier is as follows: when pH ≤ 2, the system can form a stable emulsion, which is composed of fully protonated chitosan as a free chain segment and Fe3O4@SiO2. Emulsion stabilization was achieved with monolithic Fe3O4@SiO2@CS as an emulsifier at pH > 2, and demulsification was achieved at pH ≈ pKb (CS) at 298 K. The research in this paper can provide a feasible idea and synthesis method for the preparation of organic–inorganic composite structure emulsifier.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2023
·Vol. 16
·期 24
·7576
·
IF 3.4
Tianlei Chen,Rong Zhong,Zhengjie Wang
In this study, a hydrophobic, wear-resistant ultraviolet (UV)-curable coating was investigated as an alternative to traditional coatings with low hardness and high susceptibility to scratching. The SiO2nanoparticles were ground and modified using high-energy ball milling, during which the surface energy of nano-SiO2particles rapidly increased as their particle size decreased. Different proportions of modified nano-SiO2particles were added to the coating and cured into a film. The structure of the composite coating was analyzed via infrared spectroscopy, scanning electron microscopy, and X-ray diffraction, which confirmed the successful preparation of the composite coating. The mechanical and optical property tests of the coating were investigated. With a 5% nano-SiO2content, the hardness of the coating reached 5H, whereas the adhesion was poor (2B), and the flexibility was 1. The overall comprehensive performance of the coating was best when the addition amount was 3%. The coating exhibited good hardness, flexibility, and adhesion. The hardness of the coating reached 4H, the adhesion was 4B, the flexibility was 5, the coating haze was 12.38 HZ, and the contact angle was 118°.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 10
·4214
·
IF 4.6
Tianyun Du,Xiaojie Xue,Xiuxun Han
Rare earth silicate phosphors of high quantum efficiency with a stable performance are promising materials in the fields of display and illumination. The grain sizes of products synthesized via the conventional solid-state reaction method are usually too large to satisfy the requirements of color cast and extraction efficiency in high-resolution light-emitting devices (LEDs). We designed a synthetic route and successfully fabricated rare earth silicate NaGd9Si6O26(NGSO) sub-microcrystals with a size ranging from 550 to 1200 nm. The reaction mechanism and optical properties were systematically investigated. The quantum efficiency of Eu3+-activated NGSO sub-microcrystals was about 36.6%. The LED encapsulated with these sub-microcrystals showed lower color deviation and higher lumen efficiency and lumen flux compared to that with NGSO fabricated using the conventional solid state reaction method.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Bo Li,Haocheng Yang,Hongli Song,Jie Zou,Chenchen Li,Ziyi Yan,Moyuan Qu,Wenqian Xiao,Songsong Zhu,Xiaoling Liao
Repairing bone defects is particularly challenging when an infection is presented. In this study, poly(L-lactic) (PLLA) nanofibrous microspheres (large microspheres) were used as cell carriers to simulate the nanofibrous structure of the extracellular matrix. A planet-satellite composite microsphere with large microspheres and small microspheres was constructed by bonding hollow Ag@SiO 2 nanospheres (small microspheres) to nanofibrous PLLA microspheres. According to the results, PLLA nanofibrous microspheres activated by EDC and NHS can firmly combine with Ag@SiO 2 nanospheres. The composite microspheres demonstrated excellent drug release functions, antibacterial properties, and biocompatibility and promoted cell adhesion and differentiation in vitro. The bone repair function of composite microspheres loaded with BMP2 growth factor was evaluated in rat that were infected with bacteria and exhibited skull defects. A four-week study showed that these microspheres significantly promoted bone regeneration in infected bone. These multifunctional microspheres could revolutionize bone repair and provide a much-needed solution for those suffering from infected bone defects.
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2023
·
IF 3.5
Zixu Shi,Chaoyun Shi,Huili Shi,Binfang He,Guoqiang Qin,Ao Li,Jing Zhu,Jingbo Chen
Silica-based anode material is the most concerned material at present, which has the advantages of good cycle stability, high theoretical specific capacity and abundant reserves. However, silica suffers from inherent low conductivity , severe volume expansion effect and low initial coulombic efficiency, which limits its application in lithium-ion batteries. Nanotubes structure can mitigate the volume expansion during lithiation/delithiation. In this article, silica nanotubes (SNTs) were prepared using carbon nanotubes (CNTs) as a template, and then the uniform carbon layer was coated on their surface by carbonization of citric acid . The hollow structure of nanotubes provides more sites for the insertion of Li + during lithiation and additional channels for Li + migration in the cycles, which improves the electrochemical performance. Conductivity can be enhanced by coating carbon layer. The specific capacity of the composite material is about 650 mAh g −1 at 0.1 A g −1 after 100 cycles. With a specific capacity of 400 mAh g −1 even at 1 A g −1 after 100 cycles. The silica-based material is a competitive anode material for lithium-ion batteries.
✓ 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）