Journal of the Taiwan Institute of Chemical Engineers
·
2022
·
IF 5.477
Bingying Gao,Chao Yao,Linqiang Mao
Background Advanced aerogels with lightweight, flame retardant and rapid cooling properties are urgently needed as thermal insulators in harsh environments. Method The Cr 2 O 3 −Al 2 O 3 aerogels were fabricated by simple method and freeze-dried process. A large number of pores were produced in the microstructure of samples by carbonization of soluble starch during calcination. Findings The porous structure makes the density of prepared Cr 2 O 3 −Al 2 O 3 aerogel as low as 0.0060 g·cm −3 and the thermal conductivity as high as 0.30 W m −1 ·K −1 , which indicates that the sample has good thermal dissipation and rapid cooling performance. The effect of calcination temperature on cooling rate was studied. The results show that material cooling can be divided into two stages, the second stage is the speed control step. With the increase of the calcination temperature, the cooling rate of sample improves and the cooling time decreases. The prepared Cr 2 O 3 −Al 2 O 3 aerogels have good flame retardancy and cannot ignite upon exposure to the burner for 2 min. The flame retardancy and rapid cooling mechanism of the sample was also studied. The Cr 2 O 3 −Al 2 O 3 aerogels have the advantages of lightweight, flame retardancy and rapid cooling, which has potential application prospects in the field of flame retardant cooling coatings.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Zhenhua Dang,Mingming Jia,Jun Liao,Yong Zhang,Wenkun Zhu
Al 2 O 3 aerogels have been synthesized by in situ water formation method using different agents including phenylenediamine, aniline, thiourea and urea for in-situ water formation. Then, various of techniques were implemented to analyze the structure of these as-prepared Al 2 O 3 aerogels. The results showed that the Al 2 O 3 –Th possessed the uniform porous morphology, which might provide the large specific surface area and a large number of active sites to dislodge U(VI) species. Additionally, the adsorption properties of the as-prepared Al 2 O 3 aerogels to U(VI) from solution were investigated. It could be concluded that the removal of U(VI) on Al 2 O 3 aerogels were independent on ionic strength and strongly reliant on the initial pH. The adsorption isotherms of Al 2 O 3 –Th to U(VI) could be imitated using the Langmuir model and the maximum adsorption capacities in simulated seawater and aqueous solution were 270.9 and 634.0 mg/g, respectively, which showed that the adsorption property of Al 2 O 3 –Th was much better than that of other reported Al 2 O 3 -based adsorbents. In addition, the adsorption efficiency of Al 2 O 3 –Th reached 70% within 5 min and the equilibrium of U(VI) adsorption was achieved within 100 min ( C 0 = 10 mg/L). Meanwhile, the adsorption efficiency of Al 2 O 3 –Th to U(VI) maintained quite good and the value still reached about 93% after five consecutive cycles. These results indicated that the Al 2 O 3 aerogels would be applied as potential materials for wastewater treatment .
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 21
·10397-10408
·
IF 3.3
Ning Gao,Xuanyu Gu,Jining Liu,Mengjie Fan,Yingwen Chen
At present, it is challenging to improve the activity and humidity resistance of ozone catalysts. Herein, an integrated MnOx–Al2O3 aerogel was prepared by a sol–gel method in this study, and its application in catalytic ozonation of toluene was explored preliminarily. Compared with the MnOx–SiO2 aerogel and impregnation catalysts (MnOx–silicalite-1 and MnOx–γ-Al2O3), the MnOx–Al2O3 aerogel exhibited superior performance in toluene removal and enhanced ozone utilization efficiency under optimal conditions (room temperature, O3 : C7H8 = 14 : 1, GHSV = 45 000 h−1 and 120 ppm C7H8). After reacting for 360 min, the 5 wt% MnOx–Al2O3 aerogel still showed stable catalytic ability, with the efficiency of toluene removal and ozone degradation maintained at 64.1% and 62.7%, respectively. Based on SEM characterization, the MnOx–Al2O3 aerogel demonstrated low MnOx agglomeration. From XPS and NH3-TPD analyses, it was found that the catalyst had a high content of Mn3+/Mn, Oβ/O, oxygen vacancies and acid sites, which was positively related to ozone degradation. Among them, an increase in the number of weak acid and moderately strong acid sites could prolong the life of active oxygen, which was the key to promoting the deep oxidation of toluene effectively. In addition, the MnOx–Al2O3 aerogel exhibited remarkable load-adjustability and humidity resistance. Therefore, the development of aerogel catalysts for catalytic ozonation of toluene is an effective strategy to alleviate the current ozone catalyst problem.
研究领域:
环境科学
·
催化材料
✓ 已验证
DOI
高影响因子
Nano Express
·
2021
·Vol. 2
·期 3
·030006
·
IF 0
Bingying Gao,Jinyao Cao,Yin Yan,Xiazhang Li,Wenjie Liu,Huihui Mao,Shixiang Zuo,Chao Yao,Linqiang Mao
The study of the influence of different substances introduced on the same matrix will provide a good guide for the construction of materials with good properties. A series of transitions/lanthanides metal ions doped or co-doped Al2O3 aerogel materials with three-dimensional nano porous structure were fabricated by a simple and facile modified sol-gel method. The effect of different transitions/lanthanides metal ions on the microstructure, textural properties, and luminescence properties of Al2O3 aerogels were investigated. By co-doping the Al2O3 aerogel matrix with Eu3+ and Tb3+, we fabricated Al2O3 aerogel luminescent materials with tunable color emissions under UV excitation. The characterization results showed that the microscopic morphology of these aerogels induced by transitions/lanthanides metal ions were obviously different. Interestingly, Al2O3-Eu/Tb (III) and Al2O3-Tb/Ce (III) aerogels exhibited a special flower-like structure. It is hoped that our work will offer some efforts for the preparation of functional materials with excellent properties.
研究领域:
材料科学
·
纳米技术
·
光学材料
✓ 已验证
DOI
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Feifan Chen,Bo Zhang,Weihao Cai,Nengquan Fan,Yongkang Lu,Luxia Yin,ZeKai Zhang,Wensheng Ning
Ag/SiO2–Al2O3 aerogel composites with different molar ratio of Si to Al were prepared by the sol–gel synthesis followed by drying under atmospheric pressure and then characterized by XRD, FT-IR, BET, SEM, XRF, TG-DTG, and Py-FTIR, respectively. The effect of doping Al on their physicochemical properties and adsorption desulfurization performance was investigated in comparison with Ag/SiO2. The incorporation of Al in Ag/SiO2 resulted in a gradual decrease in the specific surface area, an increase in the actual content of Ag, and an appearance of Brönsted acid centers. The actual content of Ag in Ag/SiO2–Al2O3-n increased first and then decreased with the increase in Al content. Doping Al in Ag/SiO2 led to an improvement in the adsorption capacity and the adsorptive selectivity for thiophene at the presence of toluene and cyclohexene, as well as the solvent washing regeneration performance, attributed to the adsorption of thiophenics on Ag/SiO2–Al2O3-n by π-complexation of Ag(I) and the acid–base interaction of Lewis and Brönsted centers with thiophenics simultaneously, and the increase in the actual content of Ag in the adsorbents. Ag/SiO2–Al2O3-100 had the largest adsorption capacity for thiophene and benzothiophene, 12.2 mg of S/gads (0.57 mmol of S/mmol of (Ag + Al)) and 17.7 mg of S/gads (0.53 mmol of S/mmol of (Ag + Al)), respectively.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Xinyu Zhou,Pin Mao,Huiran Jin,Wanxia Huang,Aotian Gu,Kaiwei Chen,Shan Yun,Jing Chen,Yi Yang
Cu-based functional materials are excellent candidates for the elimination of iodine anions. However, the low utilization rate of Cu and its unsatisfactory adsorption performance limit its large-scale practical applications. This paper proposes a co-gelation method to obtain Cu/Al 2 O 3 aerogels with a high specific area (537 m 2 /g). Cu/Al 2 O 3 aerogels have a hierarchical porous structure and contain a high proportion of Cu (20.5 wt%). The high dispersibility of Cu, which is based on an in-situ gel process, provides conditions for the high-efficiency elimination of iodide anions. We conducted adsorption experiments that demonstrated that the fabricated Cu/Al 2 O 3 aerogel had an ultrahigh adsorption capacity (407.6 mg/g) and a fast adsorption equilibrium time (0.5 h) for iodide anions. Additionally, the Cu/Al 2 O 3 aerogel could selectively capture iodine anions even in the presence of high concentrations of competing ions (NO 3 - , SO 4 2- , and Cl - at 60 mmol/L). Importantly, the aerogel can operate in a wide pH range of 3–11 without causing secondary pollution. This work demonstrates that low-cost Cu/Al 2 O 3 aerogels exhibit great potential for eliminating radioactive iodine anions.
研究领域:
环境科学
·
材料科学
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Bingying Gao,Jinyao Cao,Chao Yao,Linqiang Mao
Advanced aerogel materials with lightweight, flame retardant, and rapid cooling properties are urgently needed as thermal insulators in harsh environments. Herein, Cr 2 O 3 − Al 2 O 3 aerogels (CrAAs) were fabricated through a simple method and an ambient pressure drying process. A large number of pores were produced in the microstructure of the sample by the carbonization of soluble starch during calcination. The porous structure decreases the density of the prepared CrAA (Cr 2 O 3 − Al 2 O 3 aerogel) to as low as 0.143 g cm −3 , and increases the thermal conductivity to as high as 0.125 W m −1 K −1 , indicating the good thermal dissipation and rapid cooling performance of the sample. The prepared CrAAs possess a variety of composite properties such as good flame retardancy, rapid cooling, and colour restore after flame is extinguished. Moreover, after being subjected to flame treatment at ∼ 1300 °C using a butane blowtorch for 5 min, the CrAAs can be rapidly cooled to about 39.2 °C in about 1–2 min. The mechanism of the rapid cooling property was herein analysed, and we anticipate the potential application of CrAAs in flame–retardant cooling coatings.
研究领域:
材料科学
·
热工程
·
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. 106
·期 2
·393-405
·
IF 2.606
Dai Tao,Wu Zhanwu,Wang Zihan,Cui Sheng,Wu Xiaodong,Zhu Xiaofei
Fiber-reinforced aerogels with excellent properties such as low density and low thermal conductivity are potential thermal insulation materials. The slurry method and the embedding sintering method were used to fabricate MoSi 2 -aluminoborosilicate glass coatings on the surface of a carbon fiber-reinforced C-Al 2 O 3 aerogel composite under a low-oxygen atmosphere. The microstructure and phase composition of the coatings with different MoSi 2 contents before and after static oxidation were investigated. The resulting composite exhibited excellent radiating properties and outstanding oxidation resistance. The total emissivity of the as-prepared coatings was above 0.8185 in the wavelength range of 300–2500 nm. The sample with 40 wt% MoSi 2 in the outer coating had superior thermal endurance with a weight loss of only 0.54% after isothermal oxidation at 1200 °C for 180 min. This can be attributed to the optimum viscosity of the binder, which would relieve thermal stress defects and block oxygen diffusion. To further evaluate the thermal protection performance of the coatings, the heat transfer characteristics were simulated using the Fluent software package.
Graphical abstract
研究领域:
材料科学
·
热工程
·
涂层技术
·
气凝胶复合材料
✓ 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）