JOURNAL OF CRYSTAL GROWTH
·
2021
·
IF 1.797
Ming Ma,Bing Zhang,Weipeng Lu,Yihu Wang,Xiaofeng Cao,Yanchuan Guo
Calcium carbonate (CaCO 3 , CC) distributes diversely among the abiotic and biogenic minerals/biominerals. It has six phases (three anhydrous crystalline, two hydrates and one amorphous). Phase selectivity of the synthetic CC is of considerable interest and determines its physicochemical properties and destinated applications. In the present study the reactive crystallization process of CC has been subjected to the treatment of different disturbances, i.e., mechanical stirring (ms), ultrasonication (us), and composed ms + us at lower temperature (0 ± 1℃) and higher supersaturation condition (initial concentration of Ca 2+ is 0.1 M), in comparison with the quiescent condition. In order to gain insight on the role of these disturbances in controlling the crystallization process, nature, crystal habits of precipitated CC and their consecutive phase transformation, samples were collected at different time intervals (30 s, 1 min, 5 min, 10 min, 20 min, 45 min and 60 min) for investigation. Results reveals that these disturbing ways play a significant role on the CC crystallization process and can stabilize the amorphous calcium carbonate (ACC) phase for prolonged periods of time (1–60 min) in aqueous solution, which will be a powerful way for large-scale fabrication of pure ACC nanoparticles (about 100 nm) without addition of any chemicals. Longer disturbing time tends to transform the pure and spherical ACC nanoparticles competitively into spherical vaterite particles and rhombohedral calcite particles through the self-assembly of nanoparticles aggregation or Ostwald ripening mechanism, respectively. The investigation also suggested that the reactive crystallization of CC with the three disturbances undergoes a non-classical crystallization pathway to crystallize CC particles, in comparison with the quiescent reference condition. To the best of our knowledge, the report on reactive crystallization of CC crystallites as a function of different disturbances is first of its kind in the literature.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 132
·期 3
·
IF 1.64
Jianshe Bao,Si Chen,Bozhen Wu,Meng Ma,Yanqin Shi,Xu Wang
A system composed of surfactant and foam stabilizer is used in preparing porous superabsorbent resins (SARs) of poly(sodium acrylic acid) (PAA-Na), which is obtained by free-radical solution polymerization of partially neutralized acrylic acid with mechanical agitation of eggbeater. Different types of surfactant, including anionic surfactant sodium n -dodecyl benzene sulfate (SDBS), cationic surfactant cetyltrimethyl ammonium bromide, and nonionic surfactant alkylphenols poly(oxyethylene) (OP-10), are used as blowing agent to produce pores by mechanical agitation, and triethanolamine (TEA) is used to act as foam stabilizer agent. The results show that a synergistic effect of SDBS with TEA is obtained and the packing density is decreased, which could be proved by the clearly porous morphology, and the water absorbing capacity of SARs is enhanced. As a result, such method can get PAA-Na SARs without any organic solvents, which provides an environmentally beneficial way to prepare SARs for hygiene and biomedical products. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41298.
研究领域:
材料科学
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高分子化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Xuefeng Shao,Yeke Chenxu,Binrui Wang,Nan Zhang,Yanping Yuan
Towards latent heat storage for days, or even extending to months in the context of solar energy utilization, the exploration of phase change materials (PCMs) with stable supercooling and the following crystallization triggering are carried out. The present work confirmed the persistent supercooling property of the xylitol/erythritol eutectic mixture. The coupled technique combining mechanical agitation with seeding was proposed to trigger crystallization, so as to facilitate the heat retrieval whenever heat is in demand. The xylitol/erythritol eutectic keeps supercooling state without crystallization at ambient temperature for at least 10 days, thus it can serve as applicable PCM for controllable heat retrieval. Such severe supercooling is mainly attributed to the particular molecular structure of polyalcohols and dramatic increase of dynamic viscosity . In particular, on the basis of secondary nucleation principle, the coupled technique combining mechanical agitation and seeding can be a preferable technique to efficiently trigger crystallization of the present eutectic PCM , so as to realize controllable heat retrieval. Such combined technique has main advantages of high efficiency and reproducible crystallization process . The agitation duration is shortened to 1.8 min with seeding, in comparison to a longer value of 43.3 min without seeding. Although the single technique of mechanical agitation can also trigger the crystallization, the agitation is found to be time-consuming and the triggered crystallization process is in poor consistency among parallel specimens. Furthermore, the crystallization initiating is greatly advanced with high agitation rate (300 r/min), and the agitation duration to sufficiently activate crystallization can be significantly shortened. The results suggest that appropriately high agitation rate favors the efficient heat retrieval. The obtained results are helpful to gain a better understanding on the supercooled PCMs based controllable heat retrieval.
研究领域:
材料科学
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热能存储
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物理化学
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能源材料
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传热学
✓ 已验证
DOI
高影响因子
Science of Advanced Materials
·
2018
·Vol. 10
·期 11
·1552-1564
·
IF 1.318
Pan Hui,Li Guang-Long,Wang Xiao-Dong,Wang Shu-Xia,Gong Chun-Hong,Ding Tao
In this study, the spherical silica nanoparticles (denoted as PASP-K-SiO2) were firstly prepared with 3-aminopropyltriethoxy silane (KH550) and polyaspartic acid (PASP) as surface-modifiers by sol–gel method. The PASP-K-SiO2 nanoparticles were well dispersed
in water and combined with waterborne acrylic resin matrix (denoted as PAA) for preparing novel nanocomposite tanning agents (denoted as PASP-K-SiO2/PAA) successfully through a strong mechanical blending. The nanocomposite tanning agents were used to tan pickling white-wet sheepskin
and the tanned leather was characterized by rheological measurements, revealing an increase in the storage modulus and relaxation time of the leather compared to the leather tanned with bare nano-SiO2 and neat PAA. The leather tanned with PASP-K-SiO2 nanoparticles also
exhibits excellent mechanical properties, high thermal stability and chromium absorption rate. Moreover, the shrinkage temperature of the leather tanned with PASP-K-SiO2/PAA and just 0.2% chromium powder based on the sheepskin weight can reach above 80 C, which is potentially advantageous
in completely or partially replacing toxic chromium tanning agents used in traditional leather industry. Compared with the chromium tanning process, the tanning method with the nanocomposites would be regarded as eco-friendly, thus contributing to the reduction of environmental impact.
研究领域:
材料科学
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皮革化学与工程
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环境科学
✓ 已验证
DOI
高影响因子
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
·
2018
·Vol. 645
·期 2
·73-78
·
IF 1.179
Xufei Li,Bo Tang,Weiqiu Huang,Haogang Yu
Zeolite imidazolate frameworks (ZIFs) represent a class of metal-organic frameworks (MOFs) for various potential applications due to their outstanding properties. However, to date, the creation of nanoframes with tunable structure faces a challenge. Herein, we develop a facile and efficient physical method that allows the preparation of ZIF-90 with controllable surface area. In this study, the effect of various stirring time and speed in the acceleration of the precursor dissolution are revealed. The study shows that a moderate stirring speed (640 r · min –1 ) and reaction time (6 h) are the optimal conditions to synthesize ZIF-90 with a high adsorption capacity. More importantly, the maximum adsorption amount of n -hexane is up to 211 mg · g –1 by using this as-prepared sample, which increases by 60 % in comparison with that of the minimum from other sample (133 mg · g –1 ).
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Jie Huang,Xue Fan,Fei Yan,Jiyang Liu
Herein, we develop a simple electrochemical sensor based on the confinement effect of vertically ordered mesoporous silica film (VMSF) and the o-phenanthroline (Phen) chelating agent for ultrasensitive determination of ferrous ions (Fe2+). Fe(Phen)32+ obtained from the chelation between Fe2+ and Phen, shows higher electrochemical activity and larger geometric dimensions compared with free Fe2+, which could be effectively preconcentrated into the inner nanochannels of VMSF through spatial and electrostatic confinement effects. Differing from the conventional anodic stripping voltammetry, Fe(Phen)32+ could be enriched by convenient mechanical stirring and further detected by VMSF-modified indium tin oxide (VMSF/ITO), achieving an outstanding detection performance in terms of a linear range (1.0 nM–13.0 μM) and a limit of detection (LOD, 0.66 nM). Moreover, the established electrochemical sensor can accurately measure total iron and distinguish between different valence states (Fe2+ or Fe3+) with the help of reducing agents. Thanks to the outstanding antifouling ability of VMSF, the sensing platform consisting of VMSF/ITO and Phen chelating agent enables the precise determination of Fe2+ in complex real samples including tap water, pond water, FeSO4 tablets, and even colored samples, which can avoid the tedious sample pretreatment process and be applied in a wide range of scenarios.
研究领域:
分析化学
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材料科学
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环境科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Huaimin Wang,Shuang Meng,Zixuan Zhang,Chenying Zhou,Heng Zhang,Yang Liu,Chuan-shu He,Peng Zhou,Bo Lai
It has been reported that the ultrasonic agitation coupled system (US/A) has higher oxidation efficiency than the pure ultrasonic system (US), and the atomic hydrogen ( H) and hydroxyl radicals ( OH) produced by H 2 O cracking and in situ hydrogen peroxide (H 2 O 2 ) can be significantly detected. In order to utilize the residual H 2 O 2 and explore the role and fate of H, US/A/Fe(III) as an in situ Fenton oxidation system, was constructed in this study. The experimental results proved that the system can generate H 2 O 2 in situ , and adding Fe(III) could significantly promote the oxidation of refractory organic pollutants. Quenching tests, probes experiments and EPR test were performed to successfully monitor the existence of OH. The contribution of H to Fe(III) reduction was speculated and confirmed. In addition, the kinetic model showed the decomposition rate of water molecule and the reduction rate of Fe(III) by H under different ultrasonic power. The effects of the factors (pH, coexisting substance, and actual water environment) on degrading organic pollutants were evaluated. Therefore, this work provides new strategy and mechanistic insight into in situ Fenton technique by coupling ultrasonic agitation and Fe(III) without external oxidants.
研究领域:
环境科学
·
化学工程
·
水处理
·
高级氧化过程
✓ 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）