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Formation and Biomimetic Deposition of Bone-like Hydroxyapatite on wollastonite-gypsum Composites

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Journal of Bionic Engineering 2018年第5期15卷 894-906页

作者： Yaser Greish Nuha Attia Abdel-Hamid Mourad Department of Chemistry College of Science United Arab Emirates University AI Ain UAE Department of Ceramics National Research Centre Cairo Egypt Department of Mechanical Engineering College of Engineering United Arab Emirates University Al Ain UAE Mechanical Design Department Faculty of Engineering at Mataria Helwan University Cairo Egypt

Bone cements are often used for bone repair and fixation. The main objective of formulating a bone cement is to achieve structure and properties similarity to bone. In addition, bioactivity of a bone cement provides a major advantage that helps achieving better binding and interaction with the surrounding tissues. In the current study, gypsum was used as a matrix for a composite that comprises highly crys- talline prestine and acid-treated wollastonite （CaSiO3） fibers. Composites made by mixing their powder precursors with deionized water at room temperature, were investigated for their composition using X-ray diffraction （XRD） and Thermogravimetric Analysis （TGA）, for their microstructure using Scanning Electron Microscopy （SEM）, for their compressive strengths and modulus of elasticity, and for setting time measurements. In addition, cement composites were evaluated for their preliminary bioactivity in a protein-free Simulated Body Fluid （SBF） for up to 14 days. Results show the improvement of mechanical properties and bioactivity of the composites using acid-treated wollastonite fibers. This was attributed to the formation of hydrated silica layer on the surface of the acid-treated fibers which improved the binding with the gypsum matrix and provided nucleating sites for the deposition of bone-like apatite spherolites from SBF media.

关键词： gypsum wollastonite bone cement biomimetic SBF microstructure

CO_2 Sequestration from flue gas by direct aqueous mineral carbonation of wollastonite

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Science China(Technological Sciences) 2013年第9期56卷 2219-2227页

作者： YAN Heng ZHANG JunYing ZHAO YongChun ZHENG ChuGuang State Key Laboratory of Coal Combustion Huazhong University of Science and Technology

Emission of carbon dioxide is considered to be the main cause of the greenhouse effect. Mineral carbonation, an important part of the CCS technology, is an attractive option for long-term CO2 sequestration. In this study, wollastonite was chosen as the feedstock and the feasibility of direct aqueous mineral carbonation in the simulated flue gas was investigated via a series of experimental studies carried in a stirred reactor. X-ray diffraction （XRD）, X-ray fluorescence spectroscopy （XRF）, ion chro- matography （IC） and thermal decomposition were used to determine the carbonation conversion. The influences of various factors, including reaction temperature, reaction pressure, solution composition, heat-treatment and particle size, were dis- cussed. Concurrently, the effects of SO2 and NO presented in simulated flue gas were also investigated and a possible mecha- nism was used to explain the results. Experimental results show that reaction temperature, reaction pressure and particle size can effectively improve the carbonation reaction. Addition of 0.6 M NaHCO3 was also proved to be beneficial to the reaction and heat-treatment is not needed for wollastonite to get a higher carbonation conversion. Compared with carbonation in puri- fied CO2 gas, CO2 sequestration directly from simulated flue gas by mineral carbonation is suggested to have a certain degree of economic feasibility in the conditions of medium and low-pressure. A highest carbonation conversion of 35.9% is gained on the condition of T=150℃, P=40 bar and PS 〈30 μ in distilled water for 1 h.

关键词： CO2 sequestration mineral carbonation wollastonite flue gas

Effect of Applied Stresses on the Microstructure and Dissolution Behavior of Plasma Sprayed wollastonite Coatings

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稀有金属材料与工程 2012年第S1期41卷 443-447页

作者： Wang Weize Liang Jiachun Xuan Fuzhen Hong Huoxing E China Univ Sci & Technol Sch Mech & Power Engn Minist Educ Key Lab Pressure Syst & Safety Shanghai 200237 Peoples R China

wollastonite coatings were deposited on the U-shape titanium alloy coupons by atmospheric plasma *** effect of applied stresses on the microstructure and dissolution behavior of wollastonite coatings was *** microstructure and composition of coatings were examined by scanning electron microscope(SEM)and electron diffraction spectroscopy(EDS).In addition,the dissolution behavior of coatings was evaluated by immersion in simulated body fluid(SBF).More apatite is observed on the surface of coatings under a tensile stress and a stress-free condition after immersion in the SBF solution,whereas almost no apatite can be found for the coatings under a compressive *** dissolution rate of coatings characterized by the pH changes and the ion concentration of Ca,Si and P in the SBF solution is lower under the compressive stress than those under a tensile stress or a stress-free *** can be concluded from the experimental results that the compressive stress inhibits the dissolution of wollastonite coatings and the formation of apatite,whereas a tensile stress enhances the two processes.

关键词： engineering wollastonite coating stress microstructure dissolution

STUDIES ON THE APPLICATION OF TOWER MILL IN THE PRODUCTION OF ULTRAFINE wollastonite

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Journal of Wuhan University of Technology(Materials Science) 1994年第1期9卷 170-176页

作者：李冷曾宪滨 Wuhan Univ of Technology China

The feasibilities of ultrafine fvollastonits prnvder have been analysed based on joint considerations of satisfying product size re-quiremet, presenting the needlelike wollastonite structure, maintaining an easy operation, stable performance and simplified flowsheet, etc. Opti-mum operating conditions have been established through, systematic reseach-es on the bases of product requirements. Modern analytical technique such as light-transmission particle sizing and scanning electron spectroscopy have been used to determine the size and morphology of the product. It is found that the meedelelike structure can be preserved even dawn to the ul-trafine range by using the toiver mill. The torver mill is easy to operate, has stable performances, and can be used in open-circuit to produce re-quired products without needing for a classifier.

关键词： wollastonite tower mill idtrafine comminution

In vitro Evaluation with 5SBF of Alloy ASTM F75 Thermally Treated with wollastonite

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Journal of Wuhan University of Technology(Materials Science) 2016年第3期31卷 487-490页

作者： MUNIZ Rodrigo ORTIZ Juan LUNA Jesus MARTINEZ Jesus RODRIGEZ Nelly HERNANDEZ Marco OROZCO Pilar EQUIHUA Fabian Faculty of Engineering Autonomous University of CoahuilaCUSaltilloMexico Department of Metal Mechanics Technological Institute of SaltilloMexico Faculty of Engineering Mechanical and Electrical Autonomous University of Nuevo LeonMexico Faculty of Engineering Autonomous University of Zacatecas Faculty of Mechanical and Electrical Engineering Autonomous University of Coahuila North UnitMonclovaMexico

Samples of a cobalt-based alloy that underwent a surface treatment were evaluated. The samples, which were obtained by casting alloy ASTM F 75, were ground and polished on one side until a mirror finish was obtained. The samples were encapsulated in wollastonite （W） using uniaxial pressure, treated at 1 220 ~C for 1 h and subsequently tempered in water. The characterisation of the sample indicated that part of the ceramic encapsulating material was mechanically incorporated on the metallic surface by growth of the oxide layer of the alloy. After thermal treatment, a series of specimens were submerged in a solution with 5-fold simulated body fluid （5SBF） for 3, 5 and 21 days. Characterisation by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD） indicated nucleation and growth of a homogenous layer of apatite, beginning on the third day when the sample was submerged.

关键词： cobalt-based alloy wollastonite 5SBF apatite.

Evaluation on Fabrication and Properties of Composite Polyurethane Coatings with wollastonite Partially Substituting for Rutile Titanium Dioxide

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Transactions of Tianjin University 2019年第3期25卷 293-300页

作者： Xiaojing Wang Wei Zhang Yangyang Yan Jing Wang Xiyao Wang School of Chemical Engineering and Technology Tianjin University School of Environmental Science and Engineering Tianjin University

This study aims to prepare a composite polyurethane coating through a facile synthesis process. Titanium dioxide, which is a component of the prepared hydroxyl acrylic resin polyurethane varnish, was partially substituted by wollastonite, and an optimal substitution ratio was obtained. Analyses based on scanning electron microscope, powder X-ray diffraction, and Raman scattering measurements demonstrated that the addition of wollastonite caused nearly no change in the basic structure of the coating. Coating with a substitution ratio of 25% showed high thermal stability, good cover effect, considerable moisture-proof and water resistance ability, great acidic and basic resistance, and improved performance and hardness in performance tests. Furthermore, the production cost was reduced significantly at this substitution ratio.

关键词： Polyurethane coating wollastonite Rutile titanium dioxide Hydroxyl acrylic acid Thermal stability

Comparative investigations of structure and properties of micro-arc wollastonite-calcium phosphate coatings on titanium and zirconiumniobium alloy

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Bioactive Materials 2017年第3期2卷 177-184页

作者： M.B.Sedelnikova E.G.Komarova Yu.P.Sharkeev T.V.Tolkacheva I.A.Khlusov L.S.Litvinova K.A.Yurova V.V.Shupletsova Institute of Strength Physics and Materials Science of SB RAS Academicheskii pr.2/4634055TomskRussia National Research Tomsk Polytechnic University Lenina pr.30634050TomskRussia Siberian State Medical University 2 Moskovsky tr.634050TomskRussia Immanuel Kant Baltic Federal University 14 A.Nevskogo st.236041KaliningradRussia

Investigation results of micro-arc wollastoniteecalcium phosphate(W-CaP)biocoatings on the pure titanium(Ti)and Zr-1wt.%Nb(Zr-1Nb)alloy were *** voltages of 150-300 V generate the micro-arc oxidation(MAO)process with the initial amplitude current of 150-550 A and 100-350 A for Ti and Zr-1Nb substrates,*** identical dependencies of changes of the coating thickness,surface roughness and adhesion strength on the process voltage were revealed for the both *** W-CaP coatings with the thickness of 10-11μm were formed on Ti and Zr-1Nb under the low process voltage of 130-150 *** wollastonite particles with the size in the range of 40-100μm were observed in such *** structure of the coatings on Ti was presented by the X-ray amorphous and crystalline *** X-ray reflexes relating to the crystalline phases of Ti and wollastonite were observed only in XRD patterns of the coatings deposited under 130-200 V on ***,the crystalline structure with phases of CaZr4(PO4)6,β-ZrP2O7,ZrO2,and Zr was detected in the coatings on ***-IRS,XRD,SEM,and TEM data confirmed that the increase of the process voltage to 300 V leads to the dissociation of the *** toxic effect of specimens on a viability,morphology and motility of human adipose-derived multipotent mesenchymal stem cells was revealed in vitro.

关键词： Micro-arc oxidation Biocoatings Calcium phosphate wollastonite

SURFACE CHEMICAL CHARACTERISTICS AND FLOATION SEPARATION OF wollastonite AND GARNET

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Journal of Wuhan University of Technology(Materials Science) 1994年第1期9卷 65-72页

作者：方和平徐晓军罗亚田 Wuhan Univ of Tech. China

In order to nealize the efficient floatation separation of garnet and uiollastonite , the authors studied the surface chemical charac-teristics and various floatation behaviour of the two minerals?developed acidic combination depressant FDi and introduced sodium oleate j FeCls and FDi as the flotation agent, they achieved success. In the experimental re-search on the artificiallymixed ores separation, the recovery and concentra-tion grade of the two minerals ivere both over 92% and 95% respectively. At the same time , it was found that the chemical absorption form of iron oleate presented bridge and chelating patterns on the surfaces of garnet and wollastonite activated by Fe3+.

关键词： wollastonite garnet surface chemistry floatation sep-aration combination agent FD1

STUDY ON THE GRAVITATION SEPARATION OF SKARN-TYPE wollastonite ORE FOR PURIFICATION

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Journal of Wuhan University of Technology(Materials Science) 1996年第2期11卷 33-37页

作者：宋振东 Department of Mineral Resource Wuhan University of Technology China

This paper introduces the common paragenetic minerals of skarn-type wollastonite ore and its principle of gravitation separation for purification. Through the separation experiment of concentrating table on the wollastonite ore from Xiaojipu wollastonite Mine of Hubei province, the product has reached the reguirement of wollastonite powder used as the ceramic raw material.

关键词： wollastonite skarn-type gravitation separation