JOURNAL OF POLYMER SCIENCE
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2022
·Vol. 60
·期 15
·2298-2308
·
IF 3.046
Zhaolai Huang,Jiaqi Li,Mengxiao Zhang,Weilin Feng,Chuanjie Fang,Liping Zhu
Polymers of intrinsic microporosity (PIMs) are promising materials for membrane separation because their special rigid and contorted structures contribute to high permeability. However, their chain rearrangement to fill excessive free volume makes the permeability stability a tough challenge. In this work, we report on a new use of rutile nano-TiO 2 to mitigate the physical aging of PIM-1 (a typical PIM) nanofilms for stable permeability by mixing matrix. It was shown that the PIM-1 membrane incorporated with nano-TiO 2 displayed remarkably higher aging resistance with a lower swelling degree in long-term ethanol soaking, having more stable ethanol permeance with only a 5% decrease after 35 days, lower than 25% of the pure one. The mechanism of anti-aging was revealed by molecular simulation, thermal, tensile mechanical, and dynamic mechanical analysis. It was found that nano-TiO 2 had good compatibility with PIM-1 due to strong coordination interaction, making its uniform dispersion in polymer. Additional solvent permeation channels were also created to increase solvent permeance without compromising solute rejection. Due to the reliable interaction of nano-TiO 2 , which makes particles serve as physical crosslinking points, the movement of PIM-1 chains was limited partially to mitigate aging, enabling PIM-1-based membranes to have robust solvent permeation. Graphical
研究领域:
材料科学
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化学工程
·
高分子科学
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PROGRESS IN ORGANIC COATINGS
·
2017
·
IF 2.858
Xian-Wei Cheng,Jin-Ping Guan,Xu-Hong Yang,Ren-Cheng Tang
This research work reported a novel approach to develop flame retardant silk fabric using naturally occurring phytic acid (PA) rich in phosphorus and TiO 2 nanoparticles through a pad-dry-cure technique. A polycarboxylic acid [1,2,3,4–butanetetracarboxylic acid (BTCA)] was employed to stabilize and improve the adhesion of TiO 2 on silk surface. The flame retardancy of the treated silk fabric was determined in terms of limiting oxygen index, vertical burning, and pyrolysis combustion flow calorimetry, and the durability of flame retardancy to washing was discussed. PA and TiO 2 were found to have a joint flame retardant effect. The combination of PA, TiO 2 and BTCA was able to endow silk fabric with excellent flame retardancy, and the good flame retardant ability was kept even after 25 times of washing. The reasons for the good washing durability of the treated silk fabric were discussed. Finally, a significant condensed-phase flame retardant mechanism of the silk fabric treated with the PA/TiO 2 /BTCA system was revealed by the analyses of thermogravimetry and pyrolysis combustion flow calorimetry.
研究领域:
纺织科学
·
材料科学
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高影响因子
SYNTHETIC COMMUNICATIONS
·
2012
·
IF 1.062
Xi'an Chen,Huayue Wu,Shun Wang,Shaoming Huang
Nano-TiO2 is an effective heterogeneous catalyst for the ring opening of epoxides with aromatic amines to afford β-amino alcohols in good to excellent yields at room temperature under solvent-free conditions. It was found that the catalyst is recyclable, and the activity of the catalyst was not weakened markedly even after several reaction cycles. In addition, the catalytic activity of TiO2 strongly depends on particle size or surface area.
研究领域:
化学
·
催化材料科学
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高影响因子
Sustainable Energy & Fuels
·
2019
·Vol. 3
·期 11
·3234-3243
·
IF 4.912
Shiyi Deng,Yunjiao Li,Qiongyu Dai,Jiamin Fu,Yongxiang Chen,Junchao Zheng,Tongxing Lei,Jia Guo,Jing Gao,Wei Li
The elevation of energy density is the constant pursuit of the lithium-ion battery industry. LiNiO2 has reacquired recognition because it exhibits high capacity without an increase in the cut-off voltages. To address the flaws of this kind of cathodes, herein, trace nano-TiO2-modified LiNiO2 was synthesized via a simple solid-state method. Via combined characterization, the Ti element was verified to be doped into the bulk lattice and located at the transition-metal sites; after Ti doping, the Ni2+ content was clearly increased due to charge balance, followed by an increase in the Li/Ni disorder. The doped Ti and the as-generated Ni pillar mutually facilitated the stabilization of the material structure and benefitted the Li+ de/insertion. Nanosized TiO2 participating in the calcination process could effectively homogenize the size of the primary particles, adjust the surface morphology and reduce the specific surface area of the material. This morphological regulation may be favorable for reducing the contact area of the cathode with the electrolyte and establishing a stable electrode/electrolyte interface, where some detrimental side-reactions take place. With respect to electrochemical properties, Ti doping could decrease the electrode polarization, lower the impedance and promote the Li+ transfer. As a result, the Ti-modified LiNiO2 cathodes, especially the 0.2% Ti-doped (Ti-2) material, presented enhanced electrochemical performances.
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International Journal of Environmental Science and Technology
·
2018
·Vol. 16
·期 11
·7275-7284
·
IF 2.037
He Huijun,Wu Bin,Yang Chunping
The colloidal stability and photocatalysis of nano-TiO 2 particles were investigated in the presence of fulvic acids (FA) and electrolytes (NaNO 3 , Na 2 SO 4 , Na 3 PO 4 ) at different pH. Results showed that increasing FA concentration, the absolute value of zeta potential of nano-TiO 2 increased and particle size decreased at all pH which promoted the colloidal stability of nano-TiO 2 . Particle size of nano-TiO 2 was larger with the coexistence of FA and electrolytes than with FA only as the concentration of electrolytes was greater than or equal to 0.01 mol/L. The largest particle size occurred in the presence of Na 3 PO 4 , followed by Na 2 SO 4 and NaNO 3 . Particle size of nano-TiO 2 decreased with higher pH and stability further increased in the presence of FA and/or electrolytes. Nano-TiO 2 stabilization was enhanced by increasing FA concentration when the solution pH was 7.0. However, the removal efficiency of atrazine by nano-TiO 2 decreased with the increase in FA concentration. Adding electrolytes (0.01 mol/L), atrazine removal by nano-TiO 2 further decreased, albeit slightly. The inhibitory effect of electrolytes on nano-TiO 2 removal of atrazine was highest for Na 3 PO 4 , followed by Na 2 SO 4 , and NaNO 3 , which were consistent with the results of colloidal stability of nano-TiO 2 . These findings help to better understand the mechanisms and correlation between colloidal stability and photocatalysis of nano-TiO 2 in the presence of FA and electrolytes.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Jun Wen,Qiaoyu Li,Hao Li,Min Chen,Sheng Hu,Haiming Cheng
Marine bacteria play a key role in marine ecosystems and are one of the main causes of biofouling. Biofouling of adsorbents that are used for uranium recovery usually results in a decrease in uranium recovery. A novel adsorbent with antibacterial activity for uranium recovery in bacterial environments was prepared in our study to address this concern. Amidoxime-functionalized wool fibers with nano-TiO2 particles (Wool-AO@TiO2) was synthesized by radiation-induced graft polymerization combined with in situ coprecipitation of nano-TiO2 particles onto the wool fibers. The presence of nano-TiO2 on the adsorbent was verified by scanning electron microscopy with energy-dispersive X-ray spectroscopy. The maximum uranium adsorption capacity of Wool-AO@TiO2, acquired from the Langmuir isotherm, was 113.12 mg/g. The introduced nano-TiO2 imparted excellent antibacterial activity to Wool-AO@TiO2. The inhibition of Staphylococcus aureus and Escherichia coli by Wool-AO@TiO2 was 95.2% and 90%, respectively. The adsorption capacity was mostly unaffected in bacterial environments, even after four cycles of culturing with bacteria. These results suggest that the prepared Wool-AO@TiO2 adsorbent may promote the development of novel antifouling adsorbents for uranium recovery from seawater.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2018
·
IF 3.779
Yan Yang,Xiqing Xu,Jianxiong Zhao,Bin Wang,Cui Li,Xia Chen,Fang Xu
Saturation magnetization (4π M s ) and ferromagnetic resonance linewidth ( ΔH ) are vital parameters for microwave devices application. The material with high 4π M s and low ΔH is available in microwave frequency. In this work, to synthesize a ferrite material applied to X band, high saturation magnetization LiZnBi ferrite ceramics were selected as matrix. Further, in order to reduce magnetic loss of the LiZnBi ferrites sintered at low temperatures, various nano-TiO 2 were added. Interestingly, the nano-TiO 2 can promote grains growth and suitably enhance saturation magnetization and lower coercivity at low sintering temperature . Meanwhile, the ferromagnetic resonance linewidth ( ΔH ) of the ferrites can also be reduced by introducing more nano-TiO 2 particles. At last, a nano-TiO 2 substituted LiZnBi ferrite ceramics (x = 0.25) with high saturation magnetization (4π M s = ∼3367 G), low coercivity ( H c = ∼146.2 A/m) and low ferromagnetic resonance linewidth ( ΔH = ∼192 Oe) were obtained at 880 °C. The ferrite material is serviceable for X band microwave devices, such as phase shifter and circulator.
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JOURNAL OF FOOD SCIENCE
·
2018
·Vol. 83
·期 11
·2819-2826
·
IF 2.018
Yuanyuan Wu,Shuai Li,Jingxin Song,Bingxue Jiang,ShanShan Chen,Huimin Sun,Xinxin Li
Nano-titanium dioxide (TiO 2 ) was modified with the surfactant sodium laurate (SL) via ultrasonic microwave-assisted technology to improve the dispersion of TiO 2 in polymer matrices. As revealed by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy analyses, SL was well adsorbed onto the TiO 2 surface through chemical bonding, resulting in SL-modified TiO 2 (TiO 2 -SLx). The hydrophobicity and dispersibility of TiO 2 -SLx increased significantly compared to unmodified nano-TiO 2 . With an increase in the SL concentration from 5% to 15%, the agglomeration of TiO 2 -SLx particles decreased considerably, while the particles were more uniform. TiO 2 -SLx nanoparticles (3 wt%) were then incorporated into acetylated distarch phosphate/chitosan (ADPS/CS) blended matrices to reinforce the biopolymers. Relative to unmodified TiO 2 , TiO 2 -SLx exhibited a better dispersion capability. Furthermore, as the SL concentration increased, the tensile strength (TS) of the composite films increased, while the elongation at break (E), water vapor permeability (WVP), and solubility all decreased. The composite film containing TiO 2 -SL15 (TiO 2 modified with 15% SL; ADPS/CS-TiO 2 -SL15 film) displayed the highest TS (31.50 MPa), which was 33.70% higher than that of the pure ADPS/CS film, whereas the ADPS/CS-TiO 2 -SL25 film exhibited the lowest E. Further, the ADPS/CS-TiO 2 -SL15 film displayed the lowest WVP (0.90 × 10 −12 g·cm −1 ·s −1 ·Pa −1 ) and solubility (22.91%), which decreased by 30.23% and 26.03% compared to that of the pure ADPS/CS film, respectively. Therefore, SL modification and the use of ultrasonic microwave-assisted technology are promising for the preparation of nanofillers for biopolymer reinforcement. Practical Application Nano-titanium dioxide (TiO 2 ) nanoparticles were modified using the anionic surfactant sodium laurate via ultrasonic-microwave assisted technology, to improve the dispersion of the TiO 2 nanoparticles in polymer matrices. Modified TiO 2 nanoparticles were incorporated into acetylated di-starch phosphate/Chitosan blend films, causing the tensile strength of the composite film to increase and the water solubility and water vapor permeability of the composite film to decrease, making the films suitable for packaging applications.
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PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2018
·
IF 3.193
Hao Yang,Hui Zhang,Henglun Cheng,Baoqing Shentu
Nano-TiO 2 immobilized antioxidant (TiO 2 -KH550-AG) was prepared to improve the ageing resistance of thermoplastic vulcanizate (TPV) exposed to UV/O 3 . TiO 2 nanoparticles were firstly modified with 3-aminopropyltriethoxysilane (KH550) and then reacted with the antioxidant , 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid (AG), through the acyl chloride reaction followed by the amidation. FT-IR, XPS and TGA measurements confirmed that the antioxidant (AG) was chemically immobilized onto the nano-TiO 2 surfaces. TPV/TiO 2 -KH550-AG nanocomposites were prepared by melt mixing. SEM observation showed that TiO 2 -KH550-AG was homogeneously dispersed into the matrix of TPV. The UV/O 3 ageing test of the samples was carried out in the environment with constant UV intensity of 1.40 mW/cm 2 and ozone concentration of 100 ± 4 mg/m 3 . The ageing resistance behavior of the TPV/TiO 2 -KH550-AG nanocomposites was evaluated by the changes of surface morphology , mechanical properties and carbonyl index during the UV/O 3 ageing test. It was observed that the TPV/TiO 2 -KH550-AG exhibited high stability during the process of UV/O 3 ageing. The results revealed that the anti-ageing efficiency of TiO 2 -KH550-AG was superior to the mixture of the corresponding AG and modified TiO 2 , owing to the better dispersion and migration resistance of TiO 2 -KH550-AG.
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RSC Advances
·
2018
·Vol. 8
·期 51
·29172-29178
·
IF 2.936
Jie Liu,Pinghe Yin,Ling Zhao
Macroalgae, the major contributor of primary productivity in coastal seas, contribute to the material cycle and energy flow in marine ecosystems. The purpose of this work was to evaluate the toxic effect of nano-TiO2 on the growth and antioxidant activity of Gracilaria lemaneiformis. An obvious inhibition of growth was observed in this study. The algae exposed to nano-TiO2 showed a negative growth rate at 20 mg L−1 and 40 mg L−1 during the 15 days exposure. The concentration of soluble protein increased slightly during the first 3 days of exposure, but it gradually diminished thereafter due to the high concentrations of nano-TiO2 and to prolonged exposure. Nano-TiO2 caused oxidative damage in G. lemaneiformis; superoxide anions accumulated, and nitrate reductase activity decreased linearly with the increase in nano-TiO2. Furthermore, extracts of G. lemaneiformis can scavenge DPPH· and hydroxyl radicals for their antioxidant capacity. However, the capacity to scavenge DPPH· and hydroxyl radicals in vitro decreased slightly with the increase in nano-TiO2. The results from this work imply that macroalgae can be an effective biomarker of nano-TiO2 contamination and can be useful indicators to evaluate the oxidative damage of increasing pollutants in marine ecosystems.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 29
·23144-23152
·
IF 2.741
Wang Li,Lu Yixin,Yang Chen,Chen Chengyu,Huang Weilin,Dang Zhi
The stability of nanoparticles (NPs) in aquatic environments is important to evaluate their adverse effects on aquatic ecosystems and human health. Nanoparticle stability is known to be influenced by coexisting ions and dissolved organic matter. This study was designed to investigate the effects of coexisting low-level Cd(II) on the stability of humic acid-coated nano-TiO 2 (HA-TiO 2 ) particles in aquatic environments by measuring their aggregation kinetics through time-resolved dynamic light scattering (DLS) and monitoring suspended HA-TiO 2 concentrations via optical absorbance changes over time. The particles exhibited aggregation behavior consistent with the classic Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. The results showed that Cd(II) concentration, pH, and ionic strength had various effects on the aggregation kinetics of the HA-TiO 2 NPs. The HA-TiO 2 particles aggregated faster as the Cd(II) concentration increased whereas the stability of the nanoparticles increased as the solution pH increased or ionic strength decreased regardless of the Cd(II) concentration. At the fixed pH and ionic strength conditions, the addition of Cd(II) promoted aggregation of nanoparticles, leading to higher attachment efficiencies. The enhanced aggregation of the HA-TiO 2 NPs in the presence of coexisting cadmium ions in aqueous solutions indicated that the fate and transport of nanoparticles could be greatly affected by heavy metals in aquatic environments.
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BIORESOURCE TECHNOLOGY
·
2021
·
IF 9.642
Tian Zhang,Danping Jiang,Yameng Li,Huan Zhang,Zhiping Zhang,Francesco Petracchini,Valerio Paolini,Yang Zhang,Tian Yue,Quanguo Zhang
This study explored the interrelationship between nano-TiO 2 addition and photo-fermentative hydrogen production (PFHP) of corn straw. The maximum cumulative hydrogen volume (CHV) was up to 688.8 mL under the optimal photo-fermentative process conditions with nano-TiO 2 addition of 300 mg/L. Initial pH and interaction between substrate concentration and light intensity had highly significant effects on PFHP of corn straw with nano-TiO 2 addition. With the improvement of CHV, nano-TiO 2 addition decreased the optimal initial pH and substrate concentration for PFHP of corn straw. Moreover, nano-TiO 2 addition promoted the metabolism of butyric acid and acetic acid by photosynthetic bacteria HAU-M1, and significantly reduced the total concentration of intermediate byproducts during hydrogen production to a low level of 1.6–2.5 g/L, thus making the CHV, maximum hydrogen production rate (HPR) and average hydrogen content (HC) increased by 32.6%, 27.9% and 8.3% respectively over the control without nano-TiO 2 addition.
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高影响因子
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