纳米隔热浆料制备技术

本文主要研究建筑玻璃隔热涂料,从隔热材料的选择,隔热粉体的制备及隔热效果与电学性能的关系,纳米隔热浆料制备技术,建筑玻璃隔热涂料的合成及表征,和建筑玻璃隔热涂料的实际热工测试等方面对建筑玻璃隔热涂料技术进行研究,属于材料科学与建筑技术科学的交叉学科。本文从纳米ATO隔热粉体的制备入手,通过溶胶-凝胶法制备了不同Sb/Sn掺杂比例的ATO粉体,Cu,Fe掺杂的SnO2粉体及Zn共掺杂ATO粉体,研究了制备工艺对粉体微观结构,表面形貌,电学性能和光学性能的影响,并对隔热材料的隔热性能和其它性能进行了分析。当Sb/Sn=610at%,凝胶烧结温度600～800℃,保温60min时,ATO粉体具有较低的电阻率,随着Sb掺量的增加,粉体的电阻率逐渐下降,当Sb/Sn>10at%后,电阻率开始上升,ATO晶粒约为10nm。ATO粉体的电阻率与其近红外线阻隔率有着内在的联系,即降低ATO粉体的电阻率能够提高其近红外线的阻隔率即提高隔热性能。研究了pH值、分散剂和研磨时间等因素对浆料稳定性的影响。实验表明pH值在6～10的范围内,ATO浆料具有较高的稳定性。聚丙烯酰胺和多聚磷酸钠能显著改善ATO浆料的稳定性;当多聚磷酸钠为分散剂,在研磨过程中加入适量稳定剂和增稠剂可大幅提高浆料的稳定性,浆料常温保存两年没有发生沉降,延长了产品的保存期。研究的ATO浆料其固含量最高为56wt%。系统研究了建筑玻璃隔热涂料隔热性能的影响因素,并测试了建筑玻璃隔热涂料的安全性,耐水性等物理性能。降低纳米ATO浆料的平均粒径能将涂料的近红外线阻隔率提高1020%;ATO浆料固含量的提高也能增强隔热涂料的隔热性能。H1粉体能够阻隔800～1400nm的近红外线,而对1400nm～2600nm波段的近红外线阻隔效果较差。H2粉体能够阻隔600～1200nm波段的光,对1200～2600nm波段的近红外线则基本不具有阻隔作用。将H1、H2粉体分别与ATO粉体以不同比例进行复合制备成隔热浆料。随着H1、H2在复合粉体中所占比例的升高,涂料的隔热性能得到提高,但后者的可见光透射比大幅降低。采用无机硅树脂作为透明基体,与溶剂型ATO浆料配制无机硅玻璃隔热涂料。在涂料中加入H3化合物能有效提高涂料的近红外线阻隔率,同时又能尽量减少对可见光的影响。当H3含量为0.5wt%时,隔热涂料的近红外线阻隔率为93.7%,可见光透射比为61.7%,遮阳系数为0.52,τv/Se值较高为1.19。将自制的建筑玻璃隔热涂料在实际工程中进行了应用,并选取了一个相似的房间作为对比间（不应用玻璃隔热涂料）,对涂膜间与对比间进行实际热工测试,以检验建筑玻璃隔热涂料的实际隔热效果。涂膜玻璃与未涂膜玻璃相比能够阻隔大约50%的太阳总辐射。距离窗户较近的空气温度温差和黑球温度温差较其它测点大,一般西向窗户测点的温差更明显,随着测点远离窗户,测点的空气温度,黑球温度及其温差都会降低。采用红外热像仪对涂膜间与对比间的窗户进行拍摄,包括有窗帘和无窗帘两种情况,当有窗帘时,涂膜间窗帘的温度比对比间的要低约3.5℃。无窗帘时,对比间窗框温度高于玻璃温度,是隔热的薄弱环节,涂膜间的玻璃内表面温度较对比间高约7℃。玻璃涂膜后虽然提高了玻璃内表面的温度,加大了向室内的二次辐射,但其阻隔太阳辐射的能力占了主导作用,总体讲玻璃隔热涂料的隔热效果还是比较好的。通过DesT软件对两房间的室内温度进行了模拟,结果为模拟室内温度与实测的房间平均温度基本吻合,模拟值与实测值差值在0.5℃内,而且变化趋势基本一致。对比间的全年冷负荷为162.3 kW·h /m2,而涂膜间全年冷负荷为156.0 kW·h /m2。
工业羊毛毡
Building Glass Thermal Insulated Paint was mainly studied in this paper. The research was focused on the preparation of thermal insulated nano powder, the relationship between near infrared ray blocking and electricical properties, the preparation of nano slurry, the synthesis and characterization of building Glass Thermal Insulated Paint, and comparative thermal test on one classroom with building Glass Thermal Insulated Paint used on windows in one building of our school. This research field belonged to interdiscipline of material science and building science and technology.Antimony, Copper, Iron and Zinc, Antimony doped SnO2 based materials were studied by sol-gel method, especially antimony-doped tin oxide （ATO）. The factors of preparation on microstrcture, surface morphology, electricity and optical properties were analyzed. ATO nano powder had low resistivty with Sb/Sn=610at%, calcined to 600800℃for 60 min, ATO nano crystallite size was 10nm. NIR blocking ratio of nano ATO powder was increased with the increasing Sb concentration. When Sb/Sn>10at%, NIR blocking ratio declined. Though the resistivity and NIR blocking ratio of ATO powder were not linear, they were related. When the resistivity was decreased, the NIR blocking ratio would be improved.pH value, dispersant and grinding time were studied to prepare stable nano ATO slurry. When pH value=610, ATO slurry was stable. C3H5ON and Na5P3O10 could effectively improve the stability of ATO slurry. Stabilizing agent and thickener agent were added into the slurry during the process of grinding with Na5P3O10 as dispersant, which could get high stability nano slurry. The high solid content of ATO slurry was 56wt%.The effects on NIR blocking were discussed during the synsis of nano transparent thermal insulated glass paint, and environment, water resistance, hardness and anti-aging properties were mearsured. The NIR blocking ratio could be improved 1020%, when the mean grain size of nano ATO slurry was decreased effectively. The high content of ATO slurry in paint, high solid content ATO slurry could enhance the NIR blocking.Coating with ATO can only shield the near infrared from 1500nm to 2500nm. H1 powder could shield NIR from 800nm to 1400nm, and H2 powder could shield NIR from 600nm to 1200nm. H1 and H2 were added to ATO powder individually, which were prepared to get nano composite slurry. NIR blocking ratio of glass paint was increased with the increasing H1, H2 content in composite powder, and the transmittance of visible light of H2 was low.Inorganic silicon resin was first used to prepare nano transparent thermal insulated glass paint with solvent based ATO slurry. It was found that the NIR blocking rate of thermal glass paint could be improved by adding H3 compound. When H3 content was 0.5wt%, the NIR blocking rate was 93.7%, transmittance of visible light （τv） was 61.7%, Se value was 0.52, andτv/Se was 1.19.Nano transparent thermal insulated glass paint was put into practice in the classrooms of our school. Two similar classrooms were choosen as contrasted rooms, and one of them was coated with glass paint. Solar radiation, room temperature, black globe temperature, and long- wave radiation were measured. Solar radiation of coated glass was 50% of uncoated glass. The room temperature difference and black globe temperature difference near the windows were bigger than that of other measuring points. The surface temperature of curtains and windows were measured by hand-hold infrared thermal camera. The surface temperature of curtains in coated room was 3.5℃lower than that of uncoated room, and the surface temperature of glass was 7℃higher than that of uncoted room.DeST-c was applied to simulate the room temperature of two rooms. The simulation temperature was almost consistent with the practical temperature in classroom, and the temperature difference was less than 0.5℃. The cooling load of uncoated room was 162.3 kW·h /m2, and coated room 156.0 kW·h /m2.