CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jiacheng Hao,Aiqin Zhang,Zhen Pei,Jiandong Guo,Jing Jia,Husheng Jia
Rare earth red LED devices are widely used in indoor plant lighting, light therapy and other fields owning to their advantages of long life, low cost, energy saving, and environmental protection. However, their practical application is greatly limited due to the serious phenomena of deliquescence and agglomeration. In this work, a series of red-emitting Ba 3 ScB 3 O 9 :xEu 3+ phosphors have been prepared by two-step high-temperature solid state method. Ba 3 ScB 3 O 9 :xEu 3+ phosphors show an orange-red emission at 575–650 nm excited by the wavelength of 244 nm, reaching the maximum at the doping concentration of 0.05. The modified red-emitting phosphors VTES@Ba 3 ScB 3 O 9 :0.05Eu 3+ have been further prepared by surface modification with vinyl triethoxysilane (VTES). The FT-IR, XRD , XPS , and SEM analysis of the VTES@Ba 3 ScB 3 O 9 :0.05Eu 3+ phosphors show that VTES is bonded with Ba 3 ScB 3 O 9 :0.05Eu 3+ successfully. The particle size distribution of phosphors VTES@Ba 3 ScB 3 O 9 :0.05Eu 3+ is uniform, the agglomeration phenomenon is obviously weakened, and the thermal quenching is retarded. The fluorescence films have been prepared by blending phosphors with polymethyl methacrylate (PMMA). The hydrophobicity , thermal stability, and dispersibility in polymer matrix are improved. The fluorescence films have good ultra-violet resistance. It is worthy noted that the luminescent intensity of modified fluorescence films is higher than that of unmodified ones because the non-radiative transition and PL quenching of phosphors are inhibited in the modified fluorescence films. It's very gratifying to see that the brightness of the modified fluorescence films LED devices increases to 1.26 times than that of unmodified ones, and CIE color coordinates shift to red light region.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Hui Liu,Xueyi Hou,Yubin Sun,Xiangyu Zhang,Heping Li,Yanyue Lu,Zeguang Zhou
Membrane distillation technology is an important method for desalination, but it is susceptible to membrane contamination and wetting. In this study, PVDF membrane bottom surface was protected with polydimethylsiloxane (PDMS)-modified nonwoven fabric, and the membrane surface was hydrophilically modified with polymers formed from 1-vinyl-2-pyrrolidone (NVP) and vinyltriethoxysilane (VTES) to prepare the Janus membrane with hydrophilic and hydrophobic surfaces. By peeling off the PDMS-coated nonwoven fabric, part of the PDMS chains were transferred to the bottom surface of the PVDF membrane, which significantly improved the hydrophobicity of the bottom surface, and the hydrophobic contact angle of the membrane reached 152.0°. Since the casting liquid was put into a solidification bath containing hydrophilic modifier for simultaneous phase conversion into film and hydrophilic modification, the PVP-VTES was firmly anchored to the surface of the PVDF membrane through silane coupling, which resulted in excellent superhydrophilic stability of the membrane surface, and the hydrophilic contact angle reached 0°. Finally, the Janus membrane showed excellent performance in the separation of brine in DCMD. The membrane could reach a maximum flux of 43.0 kg·m −2 ·h −1 and a salt rejection rate of 99.9 % in the separation of 3.5 wt% NaCl solution. In the separation of complex salt solution, after three cycles of experiments, the salt rejection effect remained unchanged while the flux was still stable and maintained at 31.2 kg·m −2 ·h −1 . In the separation of 15 wt% NaCl solution, the membrane flux was maintained at 22.9 kg·m −2 ·h −1 after three cycles of experiment, and the salt rejection rate was still at 99.9 %. Therefore, this Janus membrane has high permeated flux and better anti-fouling properties, and it is an effective material for treating complex salt and high salinity wastewater.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Bionic Engineering
·
2021
·Vol. 18
·期 3
·559-573
·
IF 2.682
Zhang Ruilong,Zhou Zhiping,Wang Yi,Dai Xiaohui,Chen Li,Dai Jiangdong
Mimicry of nature drives the development of bionic materials. Bionic superhydrophobic materials are a kind of high-efficiency materials to handle oil spills and water pollution. However, the stability of surface coatings of the superhydrophobic materials remains a challenge. Herein, a new category of self-assembly bionic superhydrophobic surface coating was prepared via one-step condensation/copolymerization of vinyltriethoxysilane (VTES) and divinylbenzene (DVB), which realized the close combination of covalent bonds between organic ( e.g. DVB) and inorganic matter ( e.g. VTES), and avoided the swelling of polydivinylbenzene (PDVB) in the process of collection of oil from water. This organic-inorganic hybrid polymer could self-assembly deposit on the surface of sponge even other substrates. For example, P(VTES-DVB)-SiO 2 /MS obtained by assembling P(VTES-DVB)-SiO 2 on the surface of Melamine Sponge (MS) exhibited superhydrophobicity with a Water Contact Angle (WCA) of 157.3°, the optimal adsorption capacity of 77 g·g −1 − 136 g·g −1 for diverse oils, and an excellent separation efficiency of 99.3%. Besides, the excellent acid and alkali resistance of P(VTES-DVB)-SiO 2 /MS suggested the potential value in practical oil-water separation. P(VTES-DVB)-SiO 2 showed the outstanding hydrophobic performance by using as coating on different substrates. This work provided a new idea about the stable combination of organic and inorganic matter in the surface modification.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2019
·
IF 2.6
Zhuchao Yang,Huijun Yu,Xiaolei Li,Honghui Ding,Huiming Ji
A hyperelastic and hydrophobic silica aerogel has been prepared by using Vinyltriethoxysilane (VTES) and Methyltrimethoxysilane (MTMS) as the composite precursor. The effect of the VTES/MTMS molar ratio on the morphology of the VTES/MTMS-based aerogel has been investigated. The VTES/MTMS-based aerogel with a typical nano-porous structure exhibits a high surface area (321 m 2 /g), a low density (0.143 g·cm − 3 ) and low thermal conductivity (0.024 ± 0.003 W·m − 1 ·K − 1 ). The existence of methyl and vinyl groups is beneficial to enhancing the elasticities of aerogels. The MVTES5, with a VTES/MTMS molar ratio of 0.060, could bear a compressive strain of 55% and quickly recover to its original length after the stress is released. It is demonstrated that the partial replacement of the methyl with vinyl groups can greatly enhance the mechanical properties , and the compressive stress is 0.571 MPa. Furthermore, the VTES/MTMS-based aerogel exhibits hydrophobic properties with a contact angle of 146°.
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
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Xia Wang,Qihui Chen,Yangqing Zheng,Maochun Hong,Heqing Fu
First, Layered double hydroxide (LDH) was modified by toluene diisocyanate (TDI), 2-hydroxyethyl acrylate (HEA), and LDH-TDI-HEA was prepared. Then LDH-TDI-HEA was modified by vinyl triethoxysilane (VTES), and LDH-TDI-HEA-VTES composites were obtained. Finally, acrylate was modified by LDH-TDI-HEA-VTES, and flame retarded LDH-TDI-HEA-VTES-Acrylate composites were successfully synthesized by in situ polymerization. The structures of LDH, LDH-TDI-HEA, LDH-TDI-HEA-VTES and LDH-TDI-HEA-VTES-Acrylate composites were characterized by Fourier transform infrared spectra , X-ray diffraction, X-ray photoelectron spectroscopy and Scanning electron microscopic. The effect of LDH-TDI-HEA-VTES content on the thermal stability, mechanical properties , adhesion properties and flame retardant properties of LDH-TDI-HEA-VTES-Acrylate composites was studied. At the same time, the thermal stability, mechanical properties, adhesion properties and flame retardant properties of LDH-Acrylate composites and LDH-TDI-HEA-VTES-Acrylate composites were also studied. The experimental results showed that with the increasing of LDH-TDI-HEA-VTES content, the thermal stability, mechanical properties, flame retardant properties, and shear resistance of LDH-TDI-HEA-VTES-Acrylate composites were improved, while the tack and 180° peel strength decreased. When the content of LDH-TDI-HEA-VTES was 7 wt%, the LOI, after-flame time and the UL 94 grade of LDH-TDI-HEA-VTES-Acrylate composites were 27%, 0 s, and V-0, respectively. LDH-TDI-HEA-VTES-Acrylate Composites have good flame retardant properties. At the same time, the flame retardant mechanism of LDH-TDI-HEA-VTES composites was also analyzed.
研究领域:
材料科学
·
高分子化学
·
消防安全工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2012
·Vol. 70
·期 5
·1631-1645
·
IF 1.532
Zhang Yun-fei,Miao Lei,Yang Chao-long,Lu Man-geng
Modified micro-emulsion polymerization was successfully used to synthesize a kind of ambient temperature self-crosslinking core–shell emulsion, consisting of polyacrylate core and vinyltriethoxysilane (VTES) modified polyacrylate shell, by varying the ratio of soft monomer (BA) and hard monomer (MMA) which is different in the core and shell. The emulsion and its film formed at ambient temperature were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Core–shell structure was clearly shown in TEM micrographs, and two distinct glass transition temperatures ( T
g ) were confirmed by DSC analysis. Lower T
g of core phase analyzed by DSC and self-crosslinking properties of VTES characterized by crosslinking degree cause latex particles form continuous film at ambient temperature. Thermal and mechanical properties and the surface properties of the latex films were also investigated. Results showed that the core–shell latex films containing 5 and 7.5 % VTES exhibited higher thermal stability, better mechanical properties, higher contact angle, and water resistance compared with pure polyacrylate film.
研究领域:
高分子化学
·
材料科学
·
功能涂层
·
胶体与界面化学
·
有机高分子材料
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2013
·
IF 2.108
Yun-fei Zhang,Rui Zhang,Chao-long Yang,Jing Xu,Jian Zheng,Man-geng Lu
Stable acrylate/triethoxyvinylsilane (VTES) core–shell emulsion with different mass ratio of MMA/BA in the core and shell was prepared via a modified micro-emulsion polymerization process. The chemical composition and core–shell structure were investigated by Fourier transform infrared (FTIR) spectrometry, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM), respectively. Effect of MMA/BA mass ratio in the core and shell on the film-forming ability, surface tension of latex was also studied. Finally, water absorption and thermal stability of the latex films were characterized. It was found that the surface tension of emulsion can be reduced to 32.9 N/m when the MMA/BA mass ratio in the shell is 6/4. The water absorption of the latex film could be improved at a proper mass ratio of MMA/BA in core and shell, but adjusting the mass ratio of MMA/BA in the shell has little influence on the thermal stability of latex film. This work provides a method of preparing environment-friendly latex with low surface tension and excellent water resistance for coating applications by regulating the mass ratio of monomers in a modified micro-emulsion polymerization process.
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 MEMBRANE SCIENCE
·
2022
·
IF 10.53
Xiangshang Chen,Zhenjie Ma,Xihua Ren,Yue Jia,Huayan Chen,Xiaolong Lu
A novel and efficiently anchored 3-dimensional network extracting membrane (3D-NEM) with a thin functional surface layer comprising extraction carrier Bis(2-ethylhexyl) phosphate (D2EHPA) for nickel extraction was designed and studied in this paper. The active sites on the supporting Polytetrafluoroethylene (PTFE) hydrophilic ultrafiltration membrane were introduced by treating PTFE surface with potassium permanganate. Polydimethylsiloxane (PDMS) and Polymethylhydrosiloxane (PMHS) were applied to prepare a 3D network layer which is tightly anchored to the PTFE surface by introducing a crosslinking agent vinyltriethoxysilane (VTES). The prepared 3D-NEM was characterized by SEM, EDS, ATR-IR, XPS and etc. The influence of preparation parameters of 3D-NEM was studied and compared systematically. The optimum preparation conditions of 3D-NEM were based on a PDMS/PMHS/VTES ratio of 2:1:0.1 and a total polysiloxane concentration of 8 wt%. The operation stability test confirmed the average flux of the 3D-NEM in 72h reached 1871.16 mg·m -2 ·h -1 , and only 14.42% flux declined at the end of operation. The proposed designed 3D network structure produced a 5.5 μm-functional extracting layer which has benefits in both effective fixing of D2EHPA and tight anchor to the supporting surface. This work has dual advantages in improving flux and reducing extractant loss compared to supported liquid membrane (SLM) and polymer inclusion membrane (PIM) processes.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2024
·
IF 4.1
Junyan Zhao,Yu Rao,Hengyuan Zhang,Zhichen Zhu,Lihua Yao,Gaojian Chen,Hong Chen
ZnO–polymer core–shell nanoparticles were successfully prepared using a simple in situ open-to-air PET-RAFT method. The utilization of vinyltriethoxysilane (VTES) modified ZnO NPs as catalysts for polymerization, along with the grafting of polymers onto the ZnO NPs, offers significant antibacterial properties. The cationic monomer methacrylamide guanidine hydrochloride (MAGH) and the glycomonomer 2-methacrylamido glucopyranose (MAG) were grafted onto the ZnO NPs surface, further enhancing the antibacterial properties by promoting contact with bacteria and specific recognition of E. coli FimH proteins, leading to a significant improvement in the antibacterial ability compared with ZnO NPs. By combining the photocatalytic and antibacterial properties of ZnO NPs, the preparation of a core–shell material with good antibacterial properties was successfully achieved, providing a new strategy for the synthesis of antimicrobial materials.
研究领域:
纳米技术
·
材料科学
·
高分子化学
·
生物医学工程
✓ 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）