羟基磷灰石生物材料的研究现状、制备及发展前景

羟基磷灰石具有良好的生物相容性和生物活性，是较好的生物陶瓷材料。笔者论述了羟基磷灰石生物陶瓷材料的研究现状，同时对羟基磷灰石及其复合生物陶瓷材料的各种制备方法进行了概述，重点研究综合性能优越的羟基磷灰石生物陶瓷材料的制备及发展前景。     

正交试验在羟基磷灰石生物陶瓷材料制备中的应用

通过正交试验法设计湿法制备羟基磷灰石生物陶瓷材料 ,采用红外光谱(FTIR)和X -射线衍射 (XRD)对所制得的羟基磷灰石的形貌和化学组成进行分析。实验结果表明 ,反应物的初始浓度对提高羟基磷灰石的产率起着重要作用。     

有机浆料发泡法制备多孔羟基磷灰石

本文以湿法合成的羟基磷灰石粉体为原料,采用树脂、异氰酸与水发泡工艺制备多孔生物陶瓷材料。采用浆料发泡法制得的生物陶瓷材料具有三维无序孔和二维直通孔复合结构,其总气孔率可达70%～85%;宏观孔径主要分布在0.3～0.6mm之间,微观孔径主要分布在1～3μm之间,抗压强度可达0.85MPa。通过控制烧结温度,可以调节生物陶瓷材料中羟基磷灰石(HAP)和β-磷酸三钙(β-TCP)的成分配比,从而使之满足多孔生物陶瓷材料生物相容性和生物降解性的要求。     

纳米医用生物陶瓷的制备研究进展

本文综述了牙科用氧化铝基生物陶瓷、羟基磷灰石生物涂层、多孔羟基磷灰石、羟基磷灰石/聚合物可降解生物复合材料、羟基磷灰石/ZrO2生物复合材料、β-Ca2P2O7生物材料等6种纳米医用生物陶瓷的制备研究进展,并对其制备研究进行了展望.     

羟基磷灰石生物陶瓷涂层制备方法评述

根据医用生物陶瓷羟基为磷灰石及医用金属材料的生物，力学特性，本文认为在金属基体表面涂覆羟基磷灰石是综合金属材料及生物陶瓷材料各自优越性阳有希望的途径这一。评述了羟基磷灰石涂层的制备方法，论证了较为优化的涂层结构。     

羟基磷灰石生物陶瓷材料发展与应用

本文以羟基磷灰石生物陶瓷材料发展与应用为研究课题,结合羟基磷灰石生物陶瓷材料发展和应用现状,总结羟基磷灰石生物陶瓷材料应用缺陷,提出羟基磷灰石生物陶瓷材料未来发展路径,旨在为羟基磷灰石生物陶瓷材料更为广泛的应用提供理论依据。     

钛合金表面制备羟基磷灰石生物陶瓷涂层研究进展

钛合金表面制备羟基磷灰石生物陶瓷涂层以其优异的力学性能和生物活性,成为近年来材料学家研究的热点医用材料之一。本文综述了在钛合金表面制备羟基磷灰石生物陶瓷涂层的研究进展,特别是在提高涂层结合强度和涂层结晶度方面的最新研究成果,展望了钛合金表面制备羟基磷灰石生物涂层复合材料的发展趋势和前景。     

天然羟基磷灰石生物陶瓷的制备

用兽骨经过焚烧得到天然羟基磷灰石,采用超细粉碎法制备了亚微米羟基磷灰石粉体.进行了制备工艺的优化,同时结合SEM,XR,D等分析测试手段对获得的粉体进行了组分、颗粒尺度分布和微观形态分析.采用固相烧结技术制备天然羟基磷灰石生物陶瓷,确定了烧结工艺参数,即烧结温度1 350℃,烧结时间4h,并对制备的生物陶瓷样品进行了性能表征,利用XRD、傅立叶红外光谱及SEM对生物陶瓷样品的晶相组成、化学组成、形貌进行了表征.     

羟基磷灰石生物陶瓷涂层制备方法综述

羟基磷灰石生物陶瓷具有优良的生物相容性与生物活性,但强度低、韧性差的力学性能限制了它的广泛应用。医用钛及钛合金具有优良的力学性能,但耐磨性较差,同时属于生物惰性材料,与骨的结合是一种机械锁合。在医用钛及钛合金表面制备羟基磷灰石生物陶瓷涂层是目前国内外的研究热点,具有重要的理论及实践意义。本文阐述了在医用钛及钛合金表面制备羟基磷灰石涂层方法的研究现状与研究进展,并对其工艺与理论发展进行了展望。     

电泳沉积羟基磷灰石生物陶瓷涂层的研究进展

羟基磷灰石(hydroxyapatite，HAP)生物陶瓷涂层被认为是目前最好的用于替代人体硬组织的一种生物医用材料。电泳沉积是一种全新的涂层制备方法，它可以解决传统HAP生物陶瓷涂层制备工艺上的各种不足。文中综合介绍了国内外有关电泳沉积HAP生物陶瓷涂层的研究报道，概述了电泳沉积的工艺流程和工艺参数，并对各种影响因素全面地进行了详细的探讨，进而提出了相应的设想和展望。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.