SiO2气凝胶保温隔热材料在建筑节能技术中的应用

Si O_2气凝胶是一种三维空间网络结构固体材料,具有低密度、低热导率、高光透过率、高孔隙率以及高比表面积等特性,同时还兼有防火、防水等优良性能,是一种不可多得的轻质、环保、多功能材料,在建筑保温隔热领域有着广阔的应用前景。以建筑节能为目标,简要叙述了对Si O_2气凝胶的研究,从制备原材料种类的多样化,以及原材料和干燥成本降低等方面论述了其大规模生产应用的可能性,重点阐述了Si O_2气凝胶玻璃、Si O_2气凝胶隔热涂料、Si O_2气凝胶纤维复合材料以及Si O_2气凝胶混凝土和砂浆等在建筑保温隔热方面的应用研究进展;然后,从其所具备的优良特性出发,提出了一种由Si O_2气凝胶材料在建筑节能技术中的应用设想,主要从Si O_2气凝胶材料在保温隔热、防水、防火以及简化施工工艺等方面的优势,构建了全部由Si O_2气凝胶材料替代当前保温隔热材料在建筑节能中的应用体系,最后对Si O_2气凝胶材料在建筑保温隔热中的应用前景做了展望。     

气凝胶预封装高焓值定型相变水性热控涂层制备与性能研究

目的 研制一种气凝胶预封装的高焓值定型相变水性热控涂层.方法 以烷烃类相变材料为功能填料,研究了相变材料与常用溶剂的相容性,及不同预封装方式对涂层性能的影响.通过优化配方设计,制备出一种可以采用喷涂施工方式的高焓值定型相变水性热控涂料.结果 以水性树脂作为基料,以气凝胶作为预封装材料,当m(相变材料(二十二烷)):m(水性树脂):m(气凝胶)=5:2.5:1时,涂层相变焓可达139.3 J/g,涂层表面不开裂,且在高于相变温度时不发生渗漏,可弥补传统相变材料在复杂形貌结构件应用困难、结合不紧密的缺点.结论 创新地采用SiO2气凝胶将烷烃类相变材料吸入孔隙中进行预封装,后将预封装的相变材料加入水性树脂中,制备成兼具有机成膜物柔性的高焓值定型相变水性热控涂层,在力学性能优异的树脂包裹下,可避免其在形变时发生脆性断裂.涂料简单易行的施工方式,使其不再受被保护部件复杂形状的限制,从而极大地拓展了相变材料的应用范围.     

水性隔热涂料体系制备及应用研究

目的研制一种柔韧性良好的SiO_2气凝胶涂层。方法以SiO_2气凝胶为主要隔热填料,以水性树脂为基料,在多种功能助剂的配合下,制备轻质高效的隔热涂料,作为中间层漆与水性防腐底漆、水性耐候性面漆配套使用。结果以水性聚氨酯树脂作为基料,当气凝胶添加量为13%~16%时,涂层的导热系数能够达到0.05 W/(m·K)以下,涂层表面不开裂,综合性能较好。气凝胶隔热涂料与水性环氧防腐底漆、水性聚氨酯面漆配套相容性良好。结论将SiO_2气凝胶添加到有机树脂中,制备成具有有机成膜物柔性的水性隔热涂层,在力学性能优异的树脂包裹下,可避免其在形变时发生脆性断裂。涂料简单易行的施工方式,使其不再受被保护部件复杂形状的限制,从而极大地拓展涂层的应用范围。同时,涂层体系集防腐、隔热与装饰一体化,为高效防腐隔热提供了全新的解决方案。     

纳米SiO_2-稀土元素复合改性环氧树脂防腐蚀涂料的耐蚀性

通过在溶胶凝胶过程中原位添加硝酸钬、硝酸铒、硝酸钐稀土金属,制备改性纳米SiO2,并将其添加到环氧树脂中得到一种纳米SiO2-稀土金属复合改性环氧树脂涂料。用红外光谱仪对改性前后的纳米粒子进行了结构表征;采用电化学方法测试了复合改性环氧树脂涂层在3.5%NaCl溶液中的耐蚀性。结果表明,添加纳米SiO2-硝酸铒复合改性环氧树脂涂料的防腐蚀性能最佳。     

纤维掺杂疏水SiO2气凝胶的制备与表征

采用溶胶-凝胶方法成功制备了陶瓷纤维掺杂的疏水SiO2气凝胶.陶瓷纤维在SiO2气凝胶中起骨架支撑的作用来提高气凝胶的机械性能.SiO2气凝胶的机械强度从没有掺杂纤维的1.6×104Pa提高到掺杂10%纤维的9.6X 104Pa,且掺杂10%纤维的SiO2气凝胶常温常压的热导率仅为0.029 W/(m·K).掺杂SiO2气凝胶的疏水性通过表面修饰也得到了极大的提高.     

石墨烯导电涂料的研究进展

石墨烯具有超高的导电性、机械性及导热性,是目前研究最广泛的二维纳米材料,石墨烯作为特殊的功能填料,在导电防腐涂料领域得到广泛研究.首先,简要概述了石墨烯的结构特点,特殊晶体结构使其具有优异的物化性能,石墨烯作填料能够利用优异的导电性及片层结构,提升涂料的导电性及防腐蚀性.其次,针对石墨烯在导电涂料应用过程中的具体问题进行了详细说明,添加助剂以及氧化石墨烯功能化改性解决石墨烯的分散性,适量的添加量是影响导电涂料性能的关键因素,复合材料能够减少石墨烯添加量并产生协同作用,制备工艺主要包括溶液混合法、熔融共混法、原位聚合法.然后,阐述了石墨烯导电涂料的导电机理,竞争机理认为掺杂型导电涂料的导电性是由导电通路、隧道效应、场发射三者竞争的结果,结合导电模型分析了导电机理.最后,对石墨烯导电涂料的应用前景进行了展望,从石墨烯的分散方法、机理研究、制备工艺等方向,提出了石墨烯在导电涂料领域的研究建议.     

红外辐射涂料的研究与发展趋势

红外辐射涂料具有节能效果,在工业上有着日益广泛的应用.从红外辐射涂料的节能原理出发,系统地介绍了近年来国内外主要红外辐射涂料的辐射基料和粘结剂组成及研究发展状况,分析了其发展趋势与应用前景.指出红外辐射涂料的开发已经进入一个向超细超薄化、成分复合化、功能多样化方向发展的新阶段.随着涂层技术的深入研究与发展,对红外辐射涂料各方面性能的进一步了解,红外辐射涂料必将具有更加广泛的应用前景.     

SiO2气凝胶隔热涂层织物的制备及性能研究

目的提高织物的隔热效果及抗紫外性能。方法以SiO2气凝胶和TiO2为功能粒子,采用聚丙烯酸酯、聚氨酯类粘合剂,在棉织物上制备涂层,研究功能粒子和粘合剂用量对涂层织物隔热效果的影响。结果当涂层剂中粘合剂和去离子水质量比为2∶8,气凝胶加入量为粘合剂和去离子水总质量的10%时,涂层织物的隔热性能最好,较原织物显著提高。此外,SiO2气凝胶-TiO2复合涂层的隔热性能也颇为优异。织物涂覆涂层后,与原织物相比,断裂强力基本不变,撕破强力略有下降,白度提高,抗紫外性能提高,摩擦牢度好。结论采用SiO2气凝胶、TiO2作为功能粒子对织物进行涂层涂覆,其隔热性能显著提高。     

纳米SiO2的原位改性及在耐热涂料中的应用

采用溶胶-凝胶法制备纳米SiO2，并用硅烷偶联剂作为改性剂和有机相，对其进行原位改性，制备无机有机复合材料。着重研究了改性的SiO2对环氧有机硅涂料性能的影响。实验结果表明，纳米二氧化硅表面的物理吸附水和硅羟基被硅烷偶联荆的有机部分所代替，可生成改性完全并分散均匀的纳米二氧化硅复合材料。当硅烷偶联剂的用量适当时。该复合材料在环氧有机硅树脂清漆中具有良好的应用性能，可提高涂层的耐热性，同时表现出即增强又增韧的特性，显示出纳米效应。该涂料配以其它亚微米级的陶瓷粉，利用各种粉体之间的协同作用，可形成非常致密的涂层。该涂层具有良好的耐蚀性、热稳定和优异的物理机械性能。     

水性无机富锌涂料的应用研究

为了减少金属的腐蚀给人们带来的巨大损失,研究一种水性无机富锌涂料,通过与各种防腐涂料在防腐性能、安全性能以及施工性能等方面进行比较可知:水性无机富锌涂料不仅具有优良的防腐性能,方便施工,而且不易引起火灾,同时对环境没有任何污染,满足人们对环境保护的要求.水性无机富锌涂料的环保性成为目前具发展前途的环保型涂料.水性无机富锌涂料将会得到更为广泛的应用.综述了水性无机富锌涂料的成膜机理、防腐机理、类型、优越性及其在施工过程中的要求等,同时对其发展进行了展望.     

Residual stresses in thick, nonhomogeneous coatings

Residual macrostresses in thick, nonhomogeneous planar coatings are investigated theoretically using the methods of the isotropic theory of elasticity. The dependence of the elastic properties and of the sources of residual stresses on the coordinate perpendicular to the interface is considered. The results can be applied to thick graded or sandwich coatings. A simplification of the results for the cases of homogeneous and thin coatings is shown. Some differences for coatings on cylindrical and spherical surfaces are also mentioned.     

绿色防腐涂料的研究与发展

由于环保和节约资源的需要,一些具有环境友好性、使用安全性的绿色防腐涂料逐渐成为研究热点。本文对几种绿色防腐涂料(高固体分涂料、水性涂料、粉末涂料及辐射固化涂料)进行简要介绍,并展望了绿色防腐涂料的发展方向。     

The properties of electrodeposited Zn-Co coatings

The possibility of increasing the corrosion resistance of automotive sheet steel by electrodepositing with Zn-Co alloy coatings was investigated. Process variables during electrodeposition such as current density, electrolyte flow rate, and pH were varied in order to examine their influence on the electroplating process. Cobalt contents varying from 0.2 to 7 wt% were easily obtained. The influence of these process parameters on the characteristics of the coating could be related to the hydroxide suppression mechanism for anomalous codeposition. The structure and the morphology of the coatings were determined using SEM and XRD analysis. Application properties important for coating systems used in the automotive industry, such as friction behavior, adhesion, and corrosion behavior, were investigated on coatings with varying cobalt content. The corrosion resistance of the Zn-Co alloy layers was found to be better than that of pure zinc coatings.     

金属表面耐高温防腐涂料的研究进展

长时间处于高温环境中,金属易发生氧化腐蚀,从而丧失机械性能直至破坏,严重影响了使用效能的发挥。在金属表面涂覆耐高温涂层,因施工简便、成本较低、耐热性能好等优点而获得广泛应用,对于防止材料高温腐蚀、节约资源等具有重要的经济意义。对目前常用的耐高温涂料进行分类,包括有机耐高温涂料和无机耐高温涂料两大类,重点介绍了有机硅树脂耐高温涂料和无机耐高温涂料,并简单描述了有机-无机复合耐高温涂料的有关情况。对不同类别耐高温涂料的化学组成、物理性能和耐热机理等进行了阐述,并结合涂料的结构特点对各自优缺点进行了分析与比较。根据耐高温涂料在现代工业发展中的重要作用,介绍了国内外关于耐高温涂料的研究进展和应用情况,指出了不同类别耐高温涂料在使用过程中存在的问题。最后结合当前工业社会向信息化社会转变的时代背景以及研究耐高温涂层的技术意义,对耐高温涂料的发展趋势进行了展望。     

涂层在固体氧化物燃料电池金属连接体中的应用

固体氧化物燃料电池工作温度的降低,使铁素体不锈钢用作连接体成为了可能。这类连接体具有热导率高、导电性能好、热膨胀性匹配等优点,但也存在一些问题,如高价Cr的挥发以及抗氧化性弱等。涂层可以改善铁素体不锈钢的相关性能。本文综述了稀土氧化物涂层、钙钛矿涂层以及尖晶石涂层的涂层类型和涂覆方法,比较了在金属连接体中的应用效果。     

吸波涂料概述

重点对吸波涂料的吸波机理以及粘结剂和吸收剂种类进行了论述,并对吸波涂料的发展趋势进行了简单描述.     

Comparison of the tribological and antimicrobial properties of CrN/Ag, ZrN/Ag, TiN/Ag, and TiN/Cu nanocomposite coatings

Nanocomposite coatings including CrN/Ag, ZrN/Ag, TiN/Ag and TiN/Cu with varying silver or copper contents were produced by co-deposition in a dual pulsed magnetron sputtering system. The compositions and structures of the coatings were characterised using energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), and the physical and tribological properties were assessed by means of nanoindentation and thrust washer wear testing. Although increasing silver or copper content provided a reduction in the coefficient of friction, this was accompanied by reductions in hardness for all the coatings and wear resistance for some of the coatings. Zones of inhibition were used to determine the extent of silver ion release from the coating surfaces, and a NBT (nitro-blue tetrazolium) redox dye was used to determine the antimicrobial effectiveness of the coatings following incubation. The microorganisms tested were Pseudomonas aeruginosa and Staphylococcus aureus. For the NBT assays, significant reductions in the number of viable cells were observed with increasing Ag or Cu content, compared to the ‘pure’ nitride surfaces. Whilst no zones of inhibition were observed for S. aureus, on any of the surfaces, the diameter of the ‘kill’ zones generally increased with increasing silver content for P. aeruginosa.     

Study of the influence of phase composition and iron content on the formability characteristics of zinc-iron electroplated sheet steel

This study focuses on the relationship between coating composition and deformation and friction behavior of zinc-iron electroplated sheet steel. The influence of phase composition and microhardness of the deposits and the electrodeposition process parameters on the mechanical properties of the material were determined. The influence of coating composition on the friction and galling behavior was also investigated. Both V-bend test and cup test were used to evaluate the influence of the iron content on the powdering and flaking behavior of the deposits. Finally, the adhesion of the coating to the substrate was studied by lap shear tests. Although the soft η phase appears to be the main component in zinc-iron coatings with less than 16 wt% Fe, Γ₁ particles were observed even at low iron contents. As the iron content in the coating increases, the Γ₁ fraction increases and the coating becomes harder and more brittle. Above 16 wt% Fe the deposits start to show substantial powdering and flaking during deformation. At iron contents above 30 wt%, bending of the coated product results in total coating delamination. At low iron contents, zinc-iron electroplated sheet steel exhibits a superior deformation behavior, and both cup tests and flat die tests proved the suitability of the coating for deep drawing.     

An analysis of the cold spray process and its coatings

In this study, computational fluid dynamics (CFD) and extensive spray tests were performed for detailed analyses of the cold spray process. The modeling of the gas and particle flow field for different nozzle geometries and process parameters in correlation with the results of the experiments reveal that adhesion only occurs when the powder particles exceed a critical impact velocity that is specific to the spray material. For spherical copper powder with low oxygen content, the critical velocity was determined to be about 570 m/s. With nitrogen as the process gas and particle grain sizes from 5–25 μm, deposition efficiencies of more than 70% were achieved. The cold sprayed coatings show negligible porosity and oxygen contents comparable to the initial powder feedstock. Therefore, properties such as the electrical conductivity at room temperature correspond to those of the bulk material. The methods presented here can also be applied to develop strategies for cold spraying of other materials such as zinc, stainless steel, or nickel-based super-alloys.     

Development of multimaterial coatings by cold spray and gas detonation spraying

The basic objective is the development of multifunctional multimaterial protective coatings using cold spraying (CS) and computer controlled detonation spraying (CCDS).As far as CS is concerned, the separate injection of each powder into different zones of the carrier gas stream is applied. Cu-Al, Cu-SiC, Al-Al₂O₃, Cu-Al₂O₃, Al-SiC, Al-Ti and Ti-SiC coatings are successfully sprayed. As to CCDS, powders are sprayed with a recently developed apparatus that is characterized by a high-precision gas supply system and a fine-dosed twin powder feeding system. Computer control provides a flexible programmed readjustment of the detonation gases energy impact on powder thus allowing selecting the optimal for each component spraying parameters to form composite and multilayered coatings. Several powders are sprayed to obtain composite coatings, specifically, among others, WC-Co-Cr + Al₂O₃, Cu + Al₂O₃, and Al₂O₃ + ZrO₂.