SO3掺杂对高镁熟料Alite晶型和水化性能的影响

文章探讨了SO3对高镁水泥熟料中C3S晶型的调控以及对该熟料水化性能的影响。通过X射线衍射对熟料矿物含量和C3S的晶型进行表征并测试了熟料的净浆强度及结合水。研究表明:当SO3的掺量为1%、2%时不会对C3S的形成带来阻碍,样品中f-CaO含量均小于1%。在该熟料中,阿利特以M3型为主,多为细小的晶体,SO3的掺入能够稳定M1型的阿利特。1%~2%SO3的掺入能促进熟料的水化,提高熟料的中后期强度,当掺量为2%时3、28d净浆抗压强度分别提高8%和5%。水化程度随着SO3掺量的增加而增加,水化产物中含有大量的钙钒石。     

Laser‐Raman and Nuclear Magnetic Resonance (NMR) studies on plasma‐sprayed hydroxylapatite coatings: Influence of bioinert bond coats on phase composition and resorption kinetics in simulated body fluid

The structure and phase composition of HAp coatings deposited onto Ti6Al4V coupons (50x20x2mm) by atmospheric plasma spraying (APS) were studied by laser‐Raman spectroscopy, ³¹P‐ and ¹H‐MAS‐NMR and 2D‐³¹P/¹H HETCOR‐CP‐NMR spectroscopy, and XRD with Rietveld refinement. The samples investigated comprised APS HAp coatings with and without a TiO₂ bond coat as well as coatings incubated for different lengths of time (up to 12 weeks) in simulated body fluid (SBF) under physiological conditions. In APS coatings the presence of a bond coat increased the proportion of well‐ordered crystalline HAp at the expense of distorted apatite‐like structures such as oxyHAp and oxyapatite, and thermal decomposition products such as tricalcium phosphate (TCP) and tetracalcium phosphate (TTCP), and also decreased the amount of amorphous calcium phosphate (ACP). Incubation in SBF further advanced the proportion of crystalline HAp since the disordered structures, the thermal decomposition products, and ACP exhibit substantially higher solubility.     

骨组织工程支架-多孔β-磷酸三钙陶瓷的制备与性能

本文通过多孔β-磷酸三钙陶瓷的性能研究，发现将孔度提高到40％以上、孔径在100～500微米之间时，陶瓷还保持一定强度；X-射线衍射证实陶瓷组成为β—磷酸三钙晶体。预期该支架可用作骨组织工程支架。     

Luminescent calcium phosphate bioceramics doped with europium derived from fish industry byproducts

The recovery of valuable compounds from byproducts is at present a priority topic for social, environmental, and economic reasons. In this work we report for the first time the preparation of luminescent calcium phosphate (CaP) bioceramics from waste codfish bones. Codfish bones were treated in aqueous Eu(NO₃)₃ solutions of different concentrations, followed by thermal treatment at either 700°C or 1100°C. The resulting materials consisted of hydroxyapatite (HAp), β‐tricalcium phosphate (β‐TCP) and a small amount of Eu₂O₃. Chemical and structural characterization showed that the Eu ions were successfully introduced into the bones and, hence, in the thermally treated CaP phases obtained from them, although mainly in the β‐TCP lattice. Photoluminescence investigation revealed that all the materials are luminescent, with samples treated at 1100°C having more intense luminescence than those prepared at 700°C. In vitro evaluation of cell‐materials interaction indicated that all the samples displayed good cytocompatibility toward osteoblast cells. This work demonstrates that a simple and effective process, employing Eu as a dopant, can convert fish industry byproducts into highly valuable luminescent CaP bioceramics, having potential applications in biology and medicine for bio‐imaging.     

HEC-TCP复合分散体系在悬浮聚合法制备EPS珠粒中的应用研究

对羟乙基纤维素－磷酸三钙（HEC－TCP）复合分散体系的复配方法以及这一体系在以自由基型悬浮聚合法制备可发性聚苯乙烯（EPS）中的应用效果进行了研究。对实验产物相关性能指标的测试和对比分析表明，HEC－TCP复合分散体系能有效地提高EPS珠粒的品质。     

Functional Materials for Bone Regeneration from Beta‐Tricalcium Phosphate

Biodegradable ceramics of β‐tricalcium phosphate (β‐TCP, Ca₃(PO₄)₂) are widely used as bone regeneration materials. The goal is a complete regeneration of the bony defect (restitutio ad integrum = full recovery). Different bioceramics made of β‐TCP show fundamental differences in terms of phase purity, primary particle size, stability, porosity, solubility and therefore biodegradation of the material. Cerasorb® is a bioceramic consisting of phase pure β‐TCP. The primary particle size in connection with a stable sinter structure forms a porous biomaterial which is optimised in the functional surface, porosity and resorption/degradation behaviour. Different forms of Cerasorb® are available: granular materials with high and low porosity optimised for specific indications as well as block forms shapeable by the surgeon for various bony defects.     

Pulse electric current sintering of hydroxyapatite/β-tricalcium phosphate composites

Hydroxyapatite (HA)/β-tricalcium phosphate (β-TCP) composites attract attentions as bone implant materials. As one of the fabrication method of HA/β-TCP is mixing of HA and β-TCP powder in advance of sintering. This method enables to control the ratio of content of β-TCP easier. However, it is difficult to obtain dense composites. In this study, we focused on pulse electric current sintering (PECS) to obtain dense HA/β-TCP composites. The sinterability is evaluated with relative density and grain size measurements. Composition of sintered body was also characterized by X-ray diffraction. In comparison with pressureless sintering, PECS increased relative density of the composites without grain growth. In HA/β-TCP sintered by PECS, the phase transformation from β-TCP to α-TCP was promoted. This is due to higher thermal energy by spark discharge during PECS. On the other hand, sintering additives (MgO) inhibited phase transformation. It was suggested that sinterability of HA/β-TCP composites was improved by PECS.     

从新拌混凝土初始流动度和经时损失角度谈水泥的生产

从水泥水化(特别是C3A的水化)角度讨论水泥与减水剂的适应性,分析了影响混凝土流动性能的主要因素;提出了生产与减水剂适应的优质水泥的技术措施。熟料的快烧急冷、合理的水泥颗粒级配,能有效改善混凝土的初始净浆流动度及经时损失;而出磨水泥温度过高、多孔类混合材的掺入、加助磨剂的闭路粉磨工艺,均会引起水泥粒度分布变窄,导致水泥净浆初始坍落度降低。     

水泥矿物体系诱导期的水化进程及机理的研究进展

硅酸三钙(C3S)体系及铝酸三钙-二水石膏(C3A-C(S)H2)体系作为主要的硅酸盐水泥矿物相,对水泥新拌阶段及后续性能发展阶段有尤为重要的影响.而水泥在诱导期内的水化进程很大程度上决定了其后续性能的发展.鉴于此,本文回顾了水泥水化的热力学原理,重点综述了目前关于水泥水化诱导期开始及结束时作为主要矿物体系的C3S体系...