Journal of Central South University
·
2021
·Vol. 28
·期 6
·1652-1664
·
IF 1.716
Jiang Chun-lu,Wang Rui,Chen Xing,Zheng Liu-gen,Cheng Hua
Chitosan-coated fly ash (CWF) was prepared by the acid leaching-coating method. Chitosan and fly ash were crosslinked in the solution of acetic acid and sulfuric acid. The microstructure of CWF was conducted by scanning electron microscope (SEM) and X-ray diffraction (XRD). The removal of Cr(VI) from water by CWF was studied by adsorption experiments. The composite prepared by the experiment developed a pore structure and a crystal structure similar to SiO 2 and chitosan chain-like coating was formed on the surface of fly ash. The new modified material has larger surface roughness, specific surface area and more adsorption channels. The Cr(VI) was enriched in modified materials by electrostatic adsorption between CrO 4 2− , CrO 7 2− and —NH 3 + group and surface acid functional groups. The movement of Cr(VI) in solution is a diffusion process from the main body of the liquid phase to the surface of the liquid film.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2025
·
IF 6.1
Weitao Song,Huiping Song,Zhenlian Fan,Shuyan Cheng,Zhengjun Feng
Superhydrophobic coatings have attracted extensive interest from researchers in recent years. An important future development direction involves utilizing zero-cost solid waste materials as structural components to create superhydrophobic coatings. In this article, fly ash(FA), a common solid waste, was used as the main material, epoxy resin (ER) and polydimethylsiloxane (PDMS) were used as the main film-forming substances. A multifunctional FA-superhydrophobic coating ER/FA@PDMS/SiO 2 was prepared by spraying method. FA-superhydrophobic coating exhibited a water contact angle (WCA) of 156.4° ± 0.8° and water sliding angle (WSA) of 4.5° ± 0.1°. ER/FA primer has an irregular porous structure, and the PDMS/SiO 2 penetrate into the porous structure. The porous ER/FA coating can store PDMS and SiO 2 , and the FA superhydrophobic coating has similar rough structure and low surface energy inside and on the surface. FA-superhydrophobic coating have strong mechanical stability, after the surface coating is destroyed, the internal structure of the coating can still maintain excellent performance. The corrosion current density of FA-superhydrophobic coating is about 9.392 × 10 −7 A/cm 2 , which is one order of magnitude lower than ER/FA coating. FA-superhydrophobic coating can delay icing by about 121.55 % under extremely cold conditions. This simple and low-cost superhydrophobic coating has great application value in self-cleaning, anti-icing and anti-corrosion.
研究领域:
材料科学
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表面工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2018
·Vol. 10
·期 5
·523
·
IF 2.935
Limin Zang,Xuan Qiao,Lei Hu,Chao Yang,Qifan Liu,Chun Wei,Jianhui Qiu,Haodao Mo,Ge Song,Jun Yang,Chanjuan Liu
Two magnetic supports with different morphologies and particle sizes were designed and prepared for cellulase immobilization based on chitosan and industrial by-product magnetic coal fly ash (MCFA). One was prepared by coating chitosan onto spherical MCFA particles to form non-porous MCFA@chitosan gel microcomposites (Support I) with a size of several micrometers, and the other was prepared using the suspension method to form porous MCFA/chitosan gel beads (Support II) with a size of several hundred micrometers. Cellulase was covalent binding to the support by glutaraldehyde activation method. The morphology, structure and magnetic property of immobilized cellulase were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and a vibrating-sample magnetometer. The cellulase loading on Support I was 85.8 mg/g with a relatlvely high activity recovery of 76.6%, but the immobilized cellulase exhibited low thermal stability. The cellulase loading on Support II was 76.8 mg/g with a relative low activity recovery of 51.9%, but the immobilized cellulase showed high thermal stability. Cellulase immobilized on Support I had a glucose productivity of 219.8 mg glucose/g CMC and remained 69.9% of the original after 10 cycles; whereas the glucose productivity was 246.4 mg glucose/g CMC and kept 75.5% of its initial value after 10 repeated uses for Support II immobilized cellulase. The results indicate that the two supports can be used as cheap and effective supports to immobilize enzymes.Keywords:magnetic composites;chitosan;coal fly ash;enzyme immobilization
研究领域:
生物工程
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2019
·
IF 1.479
Gang Fu,Juncheng Jiang,Dan Wei,Lei Ni,Zhan Dou,Qiang Chen,Zhen Cheng
The utilization of solid particles in aqueous foam has a great potential in improving fire fighting efficiency. In this study, aqueous foam supported by micro fly-ash (FA) was prepared and its stability in a specific type of oil was characterized. Firstly, different amount of FA was added to study the influence of FA concentration on foamability. It showed that within a specific extent, foam expansion ratio increased with the increasing of FA concentration. And compared with conventional foams, oil resistance of FA stabilized foams, which was investigated by analyzing drainage rate and evolution process with a self-made apparatus, was remarkably improved when FA concentration exceed 4.8wt.%. Secondly, SiO2 and Al2O3 particles with different median sizes were used to study the effect of particle size on stability. However, the smaller hydrophilic particles didn’t behave better as expected. Moreover, the foam stability in three hydrocarbons was evaluated in the same way. The results indicated that the short chain hydrocarbons had much stronger detrimental effect to both two-phase foam and three-phase foam. But overall, the three-phase foam stabilized by FA exhibited much better oil resistance, so it can be used as a promising material for pool fire extinguishing and prevention.GRAPHICAL
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2022
·Vol. 105
·期 9
·5929-5943
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IF 4.186
Jie Ren,Hongfang Sun,Qun Li,Zhenming Li,Xiaogang Zhang,Yanshuai Wang,Linfei Li,Feng Xing
In this research, the effects of natural seawater (SW) on the properties of alkali-activated slag/fly ash (AASF) are studied. AASF prepared with deionized water is set as the reference mixture. The results showed that the use of natural SW resulted in a prolonged setting time and lower heat release, but no obvious impact on the flowability of AASF specimens. The long-term compressive strength became higher when SW was used, whereas the corresponding flexural strength and fractural toughness turned lower. The use of SW induced the formation of new products that were not identified in the reference mixture, such as Cl–hydrocalumite and gypsum. In addition, it is evidenced that the dissolution of fly ash (FA) particles was significantly delayed with the incorporation of SW. All these results were related to the various ions introduced by the natural SW and their interactions with the alkaline activator as well as the precipitation of salts on slag and FA surfaces or in the matrix.
研究领域:
土木工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
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2022
·Vol. 12
·期 2
·144
·
IF 2.67
Shun Zhou,Xiaotao Zhang,Han Zhou,Dongxu Li
In the present research work, the ternary effects of varying dosages of graphene oxide encapsulated silica fume (GOSF), nano-silica sol (SS), and fly ash (FA) on the rheological properties, compressive strength, the content and crystal size of calcium hydroxide (CH), porosity, water absorption, and microstructure of cement were studied. The results showed that the incorporation of SF improved the dispersion of GO in the cement matrix. GOSF was prepared through electrostatic attraction between the positively charged SF and negatively charged GO. The ternary mixture of GOSF, SS, and FA had a synergistic effect that improved the performance of cement. When the curing age of cement reached 28 days, the compressive strength reached a peak of 86.5 MPa, the minimum values of content and crystal size of CH were 11.55% and 45.69 nm, respectively, and the minimum values of water absorption and porosity were 0.0011 cm/s0.5and 13.56%, respectively. In terms of microstructure, the denser structure of C-S-H gel and the regular arrangement of CH were noticed.Keywords:silica fume;silica sol;graphene oxide;fly ash;orthogonal experiment
研究领域:
土木工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2018
·
IF 3.485
Baoguo Ma,Ting Zhang,Hongbo Tan,Xiaohai Liu,Junpeng Mei,Huahui Qi,Wenbin Jiang,Fubing Zou
This paper aims to investigate the effect of triisopropanolamine (TIPA) on compressive strength and hydration of cement-fly ash paste. The samples with various dosages of TIPA were prepared with 30% fly ash (FA) and 70% cement (water/binder ratio by weight = 0.38), and cured under the standard condition. The compressive strength, pore structure, hydration process, and hydration products were investigated. The results show that TIPA can obviously increase the compressive strength of cement-FA system at the age of 7 d and 60 d, and the reasons are involved in pore structure and hydration of cement-FA system. Pore structure was characterized with mercury intrusion porosimetry, and the results show that TIPA can reduce total porosity but increase the amount of pore with size more than 50 nm, implying the air-entraining effect with negative effect on compressive strength. The result suggests that TIPA and defoaming agent should be used together to minimize the negative effect in real concrete. Furthermore, analysis of hydration products shows that TIPA can accelerate the hydration of both cement and FA, and this can also be illustrated from solid-state nuclear magnetic resonance. It is noticed that TIPA can hasten the conversion of AFt to AFm, which can be indicated from hydration heat. Additionally, the acceleration of pozzolanic reaction of FA is because TIPA can accelerate the dissolution of aluminate, silicate, and ferric into liquid paste which was demonstrated from morphology characterization and the change of ions in pore solution. Such results would be expected to provide experience for the use of alkanolamine in promoting the performance of cement-based materials.
研究领域:
土木工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2022
·
IF 7.926
Miao Jiang,Kun Wang,Ruiyuan Xue,Qingliang Zhao,Long Wang,Weiye Wang,Jing Ding
Antimony (Sb) finds its wide application in industries, however, the research on Sb solidification/stabilization (S/S) in the Sb-contaminated soil is currently insufficient, particularly in seasonal freezing regions. Here six composite materials of Fe/Fe 2+ -fly ash-concrete additive (Fe-FA-CA) were employed and optimized to remediate the Sb-contaminated soil subject to 40 freezing-thawing (F-T) cycles. After remediation, FeSO 4 -fly ash-calcium lignosulfonate (FFC) exhibited the best resistance performance to F-T. The stabilization efficiency was evaluated with TCLP at 92.92%. Meanwhile, Sb concentration met the criteria of landfill for inert waste assessed with the compliance test for leaching (CT) of European Standard . The S/S efficiency of Sb dropped slightly from 92.68% to 88.22% (TCLP) and from 97.18% to 93.37% (CT), respectively, after aging 40 F-T cycles. The fraction of residual Sb in the soil treated by FFC was increased by 10.41%, and the strength of the S/S soil was much higher than 350 kPa, the requirement of landfills in the U.S. during F-T cycles. Additionally, the poorly crystalline Fe in the soil remediated by FFC was increased by 4.54 g/kg, suppressing Sb migration. The feasibility and effectiveness of FFC in S/S of Sb demonstrated its potential to remediate Sb-contaminated soil in seasonal freezing regions.
研究领域:
环境科学
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土壤学
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材料科学
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废物管理
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 22
·5628
·
IF 3.1
Xiaomin Zhang,Xiangrui Gao,Yue Yuan,Guangqin Yang,Yanchen Li
Fly ash (FA) is the main solid waste emitted from coal-fired power plants. Due to its high yield, low utilization rate, and occupation of a large amount of land, it exerts enormous pressure on the Earth’s environment. With the deepening of the concept of sustainable development, exploring the reuse of industrial waste such as FA has become a key strategy. If FA can be combined with commonly used jewelry in people’s lives, it will be of great significance to promote the high-net-worth utilization of FA. Therefore, this study synthesized a fly-ash-based composite material with color-changing function and combined it with necklaces as the main material. In the first stage, after blending fly ash and slag, an alkaline activator with a total mass of 10% was added. When the proportion of fly ash was 60%, the compressive strength of the prepared fly-ash-based composite material reached 10.1 MPa. This was attributed to the reaction between sodium silicate in the alkaline activator and free CaO, MgO, and other substances in the fly ash to form hydrated silicate colloids, which solidify the fly ash and transform it into a complex three-dimensional network skeleton. In the second stage, a UV resistant coating with thermochromic function was obtained by blending acrylic resin, TiO2, and a thermosensitive color-changing agent. It was applied to the surface of fly-ash-based composite materials, and the results showed that as the content of the color-changing agent increased, the number of pores on the surface of the coating gradually decreased. When the content of color-changing agent was 10%, the prepared 10%FAB not only had good surface color but also had good thermal stability, UV absorption ability, superhydrophobicity, and mechanical properties. Therefore, 10%FAB was selected as the basic material for jewelry design. In the third stage, the traditional Chinese technique of “gold inlaid with jade” was utilized to develop jewelry applications for the FA composites. As such, 10%FAB was processed into necklaces, which not only had modern design aesthetics but also had good color-changing effects above 30 °C. And after a long period of UV aging experiments, the necklace did not show any wrinkles, bubbles, or other phenomena. Due to the excitation of TiO2hole–electron pairs, the necklace’s UV absorption ability was further improved. This study demonstrates the potential application of industrial waste in decorative products, expands the high-end utilization of fly ash as a low-cost material, and provides new ideas for building a low-carbon lifestyle.
研究领域:
材料科学
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环境科学
·
艺术设计
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2024
·Vol. 17
·期 6
·1431
·
IF 3.1
Bao Mi,Hui Zhao,Meng Lu,Yi Zhou,Yongjie Xue
The massive stockpiling of electrolytic manganese residue (EMR) has caused serious environmental pollution. In this study, EMR, coal gangue (CG), and fly ash (FA) were used as raw materials to obtain the optimal mix ratio based on Design-Expert mixture design. The effects of activator modulus, liquid–solid (L/S) ratio, and curing temperature on the mechanical properties of geopolymers were investigated. The results showed that the compressive strength of the prepared geopolymer was 12.0 MPa, and the 28d leaching of Mn was 0.123 mg/L under the conditions of EMR:CG:FA = 0.43:0.34:0.23, L/S = 0.9, a curing temperature of 60 °C, and a curing time of 24 h. This indicates that the geopolymer is an environmentally friendly material with high compressive strength. The mineral composition of the geopolymer is mainly hydrated calcium silicate and geopolymer gel. In addition, a more stable new mineral phase, MnSiO3, was generated. The Fourier transform infrared (FTIR) spectrogram showed that the peak at 1100 m−1was shifted to 1112 cm−1, which indicated that a geopolymerization reaction had occurred. Through scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analysis, it was identified that the geopolymerization produced a large amount of amorphous gelatinous substances with a relatively dense structure, the major elements being oxygen, silicon, aluminum, calcium, and sodium.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2018
·
IF 3.485
Fubing Zou,Hongbo Tan,Xingyang He,Baoguo Ma,Xiufeng Deng,Ting Zhang,Junpeng Mei,Xiaohai Liu,Huahui Qi
Fly ash (FA) has been accepted as one of the most popular supplementary material in blends with cement. However, high content of FA added would result in very slow strength development at the early age, and this problem limits the use of FA in precast concrete. In this study, an attempt was made to enhance the early strength of steam-cured high content cement-fly ash paste (SCHF, 50% FA) by incorporating triisopropanolamine (TIPA), and the underlying mechanism was systematically investigated in terms of hydration products, pore structure, and ions dissolution of FA. The early hydration process was assessed with isothermal calorimetry, thermogravimetric with differential thermo-gravimetric, and scanning electron microscopy with energy dispersive spectrometer. The pore structure of hardened paste was characterized with mercury intrusion porosimetry. The solubility of FA was analyzed with inductive coupled plasma emission spectrometer, nuclear magnetic resonance, and scanning electron microscopy. The chelating ability of TIPA with Fe 3+ and Al 3+ was evaluated with the conductivity. These results show that with the dosage of TIPA less than 0.10%, the compressive strength will increase with increasing dosage of TIPA, mainly because of the acceleration of both hydration of cement and pozzolanic reaction of FA; while with the dosage more than 0.10%, the compressive strength was sharply decreased owing to its air-entraining effect to increase the harmful pores, with negative effect on mechanical performance. The reason for the accelerated pozzolanic reaction of FA is that TIPA can accelerate the dissolution of aluminum, ferric and silicate into solution to participate in hydration. The findings are expected to provide guidance on promoting the use of FA in precast concrete.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2022
·
IF 2.042
Zhang Xuemei,Fu Feng,Gao Xiaoming,Hou Xiufang,Niu Fengxing
The pollution of water by oil is a global challenge. In this study, the design and fabrication of a superhydrophobic stainless steel mesh are reported. This was achieved through a sample “glue + fly ash” fabrication method. The fly ash was first modified by a stearic acid solution impregnation method. After the modification, the fly ash was then bonded to the surface of a stainless-steel mesh by an epoxy resin solution to obtain the superhydrophobic mesh. The introduction to the modified fly ash endows the mesh with excellent corrosion resistance and superhydrophobicity when compared with the original mesh. The as-prepared mesh could separate various oil and organic solvents from water with a separation efficiency exceeding 98%. Interestingly, the oil separation capacity of the as-prepared mesh still kept a high value after 30 cycles of reuse. The simplicity, eco-friendliness and low cost of this method turn it into a practical and realistic approach to the large-scale fabrication of superhydrophobic surfaces. These properties make the as-prepared mesh an ideal candidate for actual oily wastewater treatment.
研究领域:
材料科学
·
环境科学
✓ 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）