IONICS
·
2023
·Vol. 29
·期 11
·4669-4679
·
IF 2.8
Tang Liping,Wu Yankang,Lei Zhiqiang,He Yu,Chen Jian
An in situ–grown TiO 2 membrane was prepared by an electrospinning method using polyacrylonitrile as the spinning precursor, combined with the TiO 2 hydrolysis mechanism. The performance of tetrabutyl titanate and isopropyl titanate as two titanium source precursors hydrolyzed under the inhibition of acrylic acid to produce TiO 2 with different contents for lithium-ion batteries was compared. The experimental results showed that when both titanium sources were prepared at 3 wt%, the comprehensive performance of the separator manufactured with tetrabutyl titanate as the titanium source (PAN/TBT-3) and isopropyl titanate as the titanium source (PAN/TPT-3) was finest than that of the Celgard 2400 and the composite membrane with direct TiO 2 addition (PAN/TiO 2 -3). The tensile strength of PAN/TPT-3 and PAN/TBT-3 membranes were 7.82 MPa and 4.03 MPa higher than that of Celgard 2400, and 17.03 MPa and 13.29 MPa higher than that of PAN/TiO 2 -3 separator, respectively. PAN/TPT-3 and PAN/TBT-3 membranes exhibited a discharge capacity of 107.72 mAh/g and 115.79 mAh/g at 2 C, and both the capacity retention rate was above 99.5% higher than 80.5% for Celgard 2400.
研究领域:
材料科学
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纳米技术
·
储能
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 7
·6954-6962
·
IF 2.195
Jiang Nan,Du Yi,Du Minxing,Feng Yibing,Liu Yang
TiO 2 nanobelts with different synthesis methods have been actively pursued for a long time, however, a systematic study corresponding to the fabrication of TiO 2 nanobelts by alkali-hydrothermal method has not been worked out by any research. Here, we systematically study the conditions such as the source of Ti and hydrothermal parameters with the assistance of X-ray diffraction (XRD), scanning electron microscope (SEM), N 2 -sorption measurement and photochemical tests. The XRD and SEM measurements show that the TiO 2 nanobelts exhibit excellent belt-like structures and high crystalline intensity when using tetrabutyl titanate (Ti(OBu) 4 ) as the source of Ti, the volume of 10 mol/L NaOH is 15 mL, the hydrothermal reaction is conducted at 180 °C for 20 h and the heat treatment system is 800 °C for 2 h. The length–diameter ratio of the final obtained sample is about 130 and the specific surface area is 50.4 m 2 /g.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 9
·3296
·
IF 3.4
Wenqi Zou,Hongli Bian,Jinjing Guo,Jun Xu,Baohua Guo
Titanates are widely used in the synthesis of polyesters, such as Poly (butylene succinate) (PBS), due to their excellent catalytic activity for polycondensation. However, the hydrolysis sensitivity of titanate and side reactions at high temperatures restrict the further improvement of the molecular weight of polyesters and lead to the high content of end carboxyl group content in the products. In this work, we prepared titania–silica composite aerogels with resistance to hydrolysis and large specific surface area, which were further explored as an efficient catalyst for polycondensation reactions. A series of titania–silica composite aerogel catalysts for PBS polycondensation were successfully prepared by the sol-gel method. The influence of a Ti/Si ratio on the surface morphology and structure of the aerogels was examined. Titania–silica composite aerogel exhibits the surface characteristics of high specific surface area and high Lewis acid content. The specific surface area of titania–silica composite aerogels can reach 524.59 m2/g, and the Lewis acid content on the surface can reach 370.29 μmol/g. Furthermore, the catalytic performance for the polycondensation reaction of PBS was investigated. The intrinsic viscosity of PBS synthesized by catalysis with the composite catalyst with a Ti/Si ratio of 9/1 reaches 1.74 dL/g, with the Mnof 7.72 × 104g/mol. The hydrolysis resistance stability of the titania–silica composite aerogel is greatly improved compared with traditional tetrabutyl titanate (TBT), and the end carboxyl group content of PBS is effectively reduced to lower than 30 mol/ton.Keywords:Poly (butylene succinate);aerogel;catalysts;titanates;polycondensation
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2023
·
IF 6.2
Dian Wang,Xiang Wan,Jiafei Wang,Debby Mangelings,Qin Xu,Fazhi Xie,Xianhuai Huang,Weihua Li,Han Xuan,Wensheng Zou,Qishu Qu
Background Due to its high chemical stability, sufficient rigidity and zwitterionic ion exchange properties, TiO 2 can be considered as an alternative stationary phase material to SiO 2 for high performance liquid chromatography . TiO 2 stationary phase is usually prepared by coating TiO 2 onto SiO 2 support by sol-gel method. However, in the traditional coating method, in order to overcome the rapid hydrolysis rate of tetrabutyl orthotitanate, only a very low concentration of tetrabutyl orthotitanate can be used, resulting in a low loading of TiO 2 on the support. Results TiO 2 core-shell spheres with a good monodispersity were prepared using 0.25 mol L −1 tetrabutyl orthotitanate. The specific surface area, pore volume , pore diameter and TiO 2 loading of the TiO 2 core-shell spheres were 66 m 2 g −1 , 0.15 cm 3 g −1 , 9.8 nm and 57%, respectively. The core-shell spheres were derivatized with n-octadecyltrichlorosilane and then packed into a stainless steel column to test the separation performance for neutral, basic and acidic samples in liquid chromatography. A baseline separation of polyaromatic hydrocarbons was achieved, showing a column efficiency for fluorene of 118075 plates m −1 . The prepared stationary phase was also used to separate acidic and basic mixtures, and column efficiencies of 54500 and 25836 plates m −1 were obtained for N , N -dinitroaniline and p -chlorophenol, respectively. The relative standard deviations of the retention times of polyaromatic hydrocarbons for run-to-run, day-to-day and column-to-column repeatability were all below 5.1%. Significance and novelty This work demonstrated that TiO 2 can be coated in the pores of the shell of SiO 2 core-shell spheres with high TiO 2 loading using a high concentration of tetrabutyl orthotitanate as the titania source. The experimental results show that the TiO 2 coated core-shell spheres can be a good alternative stationary phase for liquid chromatography.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2025
·
IF 7.3
Xuewu Li,Chenghu Ma,Tian Shi,Hejie Yang
The corrosion failure of aluminum‑lithium (Al Li) alloy, extensively used in aerospace and industry area, inevitably brings about considerable economic loss. In this work, stearic acid (STA) is utilized as a modulator for the low surface energy modification of TiO 2 particle. Polyurethane (PU) is employed as a binder to ensure the firm adhesion of modified STA@TiO 2 to Al Li alloy through a controllable and low-cost spraying process. Such structure design brings about a robust preparation of STA@TiO 2 /PU superhydrophobic coating for large-scale engineering application. The resultant coating exhibits a static water contact angle (CA) of 161.3 ± 0.8°, and a sliding angle (SA) of 3.1 ± 0.7°. The subsequent characterizations of surface morphology and chemical structure are performed using SEM, EDS, XPS, and laser confocal microscopy. Furthermore, the contrastive electrochemical impedances and kinetic potential polarizations are investigated on as-prepared coating and Al Li alloy substrate. The results indicate that the impedance modulus of STA@ TiO 2 /PU coating is enhanced by two orders of magnitude, while the corrosion potential demonstrates an increasement of 180 mV. The experimental tests confirm a significant improved corrosion resistance for STA@ TiO 2 /PU coating. Moreover, the effective self-cleaning, anti-pollution, buoyancy enhancement and anti-icing properties are discussed, and the corresponding interface behaviors and function implementation mechanisms are also systematically investigated. The findings have positive implications for expanding industrial applications of such multi-functional ceramic coatings in engineering construction, environmental protection, and harsh working conditions.
研究领域:
材料科学
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表面工程
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Haihua Wang,Yanyu Li,Guiqiang Fei,Liyu Sun,Yanping Wang,Xuan Liu,Mengxi Wang,Nana Rang
Hydrophilic functionalization of reduced graphene (RGOs) is able to improve its dispersibility in aqueous polymer. However, the influence of hydrophilic segments on the chemical resistance of RGOs/polymer nanocomposites keeps indistinct. Here, we prepared RGOs functionalized with hydrophilic chelated titanate (TA) and non-chelated titanate (T), named as TARGOs and TRGOs, respectively. The intercalation reaction mechanism between titanate and GO was elucidated. The presence of hydrophilic triethanolamine in titanate had little impact on the structural disorder of RGOs, but can effectively improve the exfoliation degree and the dispersibility of functionalized RGOs in waterborne alkyd resin (WAAR). The water resistance and thermal stability of TARGOs/WAAR were inferior to that of TRGOs/WAAR. The initial impedance modulus and coating resistance of TARGOs/WAAR were higher than TRGOs/WAAR at the same RGOs content when the RGOs content is 0.5% owing to the more homogeneous distribution of TARGOs in WAAR. However, the corrosion resistance of TARGOs/WAAR significantly decreased when the TARGOs content increased to 0.7%, which can be attributed to the presence of hydrophilic regions. In contrast, TRGOs/WAAR displayed the optimum long-term corrosion resistance when the TRGOs content was 0.7%, even though the dispersion of TRGOs in WAAR cannot be comparable to TARGOs in WAAR.
研究领域:
材料科学
·
防腐蚀工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2017
·
IF 4.873
Penghao Hu,Shengmin Gao,Yangyang Zhang,Liang Zhang,Chengchen Wang
Dielectric capacitors are promising in micro-electronics, portable equipment and hybrid electric vehicles due to their specific features of flexibility, ultrahigh operating voltage and fast charging-discharging rate. The dielectric properties of polymer-based nanocomposite are much related to the interface binding between fillers and matrix. In this work, a surface modification approach employed newfound titanate coupling agent was developed to improve the compatibility between BT nanoparticles and PVDF matrix. After treated by the modifier TC-2, a coating layer contained with active organic groups was formed on the surface of BT nanoparticles. Benefited from the improved dispersibility and compatibility of modified BT nanoparticles in PVDF matrix, the breakdown strength of the nanocomposites was much enhanced. The monodisperse mBT-2 nanoparticles treated with appropriate amount of modifier dramatically enlarged the breakdown strength from 397 kV/mm for neat PVDF to 517 kV/mm for 4 vol% mBT-2 loading nanocomposite. Compared with BT/PVDF, the improvements on the energy storage performance in mBT-2/PVDF are significant. The maximum discharged energy density of 11.27 J/cm 3 for 4 vol% loading mBT-2/PVDF is nearly double of that for 4 vol% loading BT/PVDF, and the energy efficiency for mBT-2/PVDF is also increased. The modification method originally represented here has great potential in developing high energy density nanocomposites for advanced applications.
研究领域:
材料科学
·
电介质物理
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 24
·52342
·
IF 3.057
Xu Han,Ying Guo,Huanhuan Cai,Xiang Li,Jiangnan Ding,Xiaojuan Zhao,Heng Zhou,Wantao Guo,Wei Huang,Tong Zhao
To improve the flame retardancy of vinyl epoxy (VE) resins more effectively, a half-cage and cage structure polyhedral oligomeric silsesquioxanes (P/N-POSS) containing phosphorus and nitrogen was synthesized by a one-step Kabachnik-Fields reaction from paraformaldehyde, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and 3-aminopropyltriethoxysilane. It was then blended with tetrabutyl titanate (TBT) in VE resins to construct a phosphorus-nitrogen-silicon-titanium synergy flame retardant system. P/N-POSS was well dispersed in the VE matrix at low loadings (≤4 wt%). With the addition of only 4 wt% P/N-POSS and 0.2 wt% TBT, the LOI value reached 29.2 and the UL-94 grade passed V-1 rating. Moreover, compared with VE-0, the peak heat release rate, total heat release, smoke production rate and total smoke production decreased significantly. The investigations on pyrolysis volatiles and char residue of cured VE composites revealed that the excellent flame retardancy of the VE composites were due to the superior free radical capturing ability, the dilution effect of P/N-POSS in the gas phase, and the promoting the carbonation effect of P/N-POSS, the catalyzing char formation ability of TBT in the condensed phase. Meanwhile, VE composites exhibited improved mechanical properties, thermal stabilities and retained the low viscosity and good processability of VE resins.
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 APPLIED POLYMER SCIENCE
·
2018
·Vol. 136
·期 8
·47098
·
IF 1.901
Zhuo Li,Jijun Wan,Yingzhe Li,Yang Li,Fei Zhao,Shugao Zhao
The effects of various coupling agents on the characteristics and properties of a natural rubber (NR)/styrene–butadiene rubber (SBR) matrix and its adhesion to continuous basalt fiber (CBF) cords were studied. Four types of silane-based and two types of titanate-based coupling agents were added separately to the rubber matrix during the mixing process. The processability of the rubber compounds and the mechanical and tension fatigue properties of the vulcanizates were evaluated. The static and dynamic adhesion between the CBF cord/rubber matrices were investigated using the H pull-out test and an elastomer testing system, respectively. The results showed that the effects of the coupling agent were controlled by its chemical structure, and it was found that the addition of (3-aminopropyl)triethoxysilane was the most effective for enhancing the interfacial fatigue properties, due to the combined improvements of the initial adhesion, interfacial stress states, and the fatigue property of the rubber matrix. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47098.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 4
·966-979
·
IF 2.482
Liu Qinglong,Yang Jingchao,Luo Mingsheng,Yang Zhi,Zhao Qiuna
Abstract A series of Mn–Ti oxide catalysts were synthesized by the sol–gel method and the effects of different synthesis conditions were investigated in sequence. The microstructures and properties of the catalysts were characterized by using N 2 adsorption–desorption, XRD, SEM, H 2 -TPR, NH 3 -TPD, Raman and XPS. The catalytic performance over Mn–Ti oxide catalysts prepared under different synthesis conditions for the low-temperature SCR of NO with NH 3 were also comparatively evaluated. The results reveal that the calcination temperature and metal source play a significant role in the characteristics and the SCR activities of the catalysts. A relatively low calcination temperature is beneficial to low-temperature SCR activity. Manganese nitrate or manganese acetate as the Mn source combining with tetrabutyl titanate as Ti source can achieve high SCR activities. The excellent low-temperature NH 3 -SCR activity can be ascribed to the appropriate textural properties, amorphous Mn-oxides with equal ratio of Mn 3+ /Mn 4+ , good low-temperature reducibility and abundant surface B-acid sites. Graphic Abstract
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Yao Fu,Jian Li,Pengzhen Li,Huajie Tao,Xianfu Luo,Dongjian Wang,Yiting Shan,Hongqing Zhou
In this work, the titanate coupling agent KR-TTS was used in tape casting of CaO–B 2 O 3 –SiO 2 (CBS) glass-ceramics to obtain a high-performance dielectric tape. The functional group ((RO) m ) of KR-TTS could directly react with the hydroxyl (–OH) of the CBS powders, which made the feature of powders from hydrophilicity into hydrophobicity . The modification mechanism of the modifier KR-TTS was illuminated by infrared absorption spectrum and contact angle of powders with modifier KR-TTS. The optimum amount of KR-TTS was determined by the rheological properties of suspensions, the density and the tensile strength of the green samples, the density and dielectric properties of the sintering samples sintered at 835 °C. The surface modification of CBS glass-ceramic by KR-TTS has made a substantial breakthrough in improving the densification and the mechanical performance of the green tapes. When the amount of KR-TTS was 1.0 wt%, the stability of slurry and the properties of the green samples had been greatly improved. The density of the green samples with 1.0 wt% KR-TTS reached 1.59 g/cm 3 and the tensile strength of the green samples reached 2.43 MPa. The sintering sample with 1.0 wt% KR-TTS realized sintering densification and performed better dielectric properties. The sintering density reached to 2.51 g/cm 3 . The permittivity and dielectric loss were ε r = 5.92 and tanδ = 13 × 10 −4 at 10 GHz.
研究领域:
材料科学
·
无机非金属材料
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 50
·31628-31640
·
IF 3.108
Yunhua Lu,Weipeng Zhang,Xingwei Li,Shiai Xu
Six new polyether titanate coupling agents with different polyethyleneglycol (PEG) segment lengths were prepared in this study and were then used to modify calcium sulfate whiskers (CSWs) in order to improve the compatibility between CSWs and poly(vinyl chloride) (PVC). The chemical structure of these coupling agents was characterized by FTIR, Raman, 1H NMR and 31P NMR, and the surface properties of CSWs modified by the coupling agents (mCSWs) were characterized by FTIR, SEM-EDS and XPS. Then, CSW/PVC and mCSW/PVC composites were prepared using a two-roll mill, and their mechanical and thermal properties were characterized to investigate the effects of the PEG segment length of the coupling agents on the performance and compatibility of the composites. The results show that the new coupling agents can significantly improve the compatibility and the interfacial adhesion between CSWs and the PVC matrix, which results in a significant improvement of the comprehensive performance of mCSW/PVC composites. PEG4000 shows the best modification effect on CSWs. Finally, the underlying mechanisms are discussed.
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
危险品化学品经营许可证（带存储）