蜂窝状陶瓷载体涂层的研究——Al_2O_3胶液的触变性

研究了制备蜂窝陶瓷涂层使用的AL_2O_3胶液的触变性以及影响胶液触变性的因素,并对胶液的触变性对蜂窝陶瓷涂层的上涂量的影响进行了探讨 结果表明,影响胶液触变性最大的因素是含固量:若使胶液具有触变性,含固量只能在一定范围内波动,且含固量越高,胶液的触变性越明显;稳定剂、表面活性剂以及醋酸都影响胶液的触变性;而胶液的触变性有利于蜂窝陶瓷涂层的上涂量的提高.     

叶面喷施硅铈复合溶胶对水东芥菜重金属含量及其他品质的影响

田间小区试验研究了叶面喷Si、喷Ce以及喷Si+Ce处理对水东芥菜生长、地上部重金属Cd、As、Pb、Cr、Hg含量,以及维生素C（Vc）、可溶性糖、硝酸盐、亚硝酸盐含量等品质的影响。结果表明：叶面喷Si、喷Ce以及喷Si+Ce处理,均可以促进水东芥菜生长,增加水东芥菜地上部鲜物质和干物质重量;尤其是叶面喷Si+Ce处理后水东芥菜地上部鲜物质和干物质重量比对照分别增加了6.2%和16.2%;差异达到显著水平。与对照相比,叶面喷Si、喷Ce以及喷Si+Ce处理后水东芥菜地上部Cd含量分别下降了24.5%、22.9%、42.6%;As含量分别下降了26.4%、26.0%、40.0%;Pb含量分别下降22.5%、32.5%、36.8%;差异都达到显著水平。但是各处理对水东芥菜地上部 Cr 和 Hg 含量并无显著影响。与单独喷 Si 或单独喷Ce相比,叶面喷Si+Ce复合处理对降低水东芥菜地上部Cd和As含量效果更佳。叶面喷Si、喷Ce以及喷Si+Ce处理,还可以显著增加水东芥菜地上部Vc、可溶性糖含量,显著降低其硝酸盐、亚硝酸盐含量;同时叶面喷施Si+Ce处理后水东芥菜地上部亚硝酸盐含量是分别单独喷Si、喷Ce的80.3%和79.1%,差异达到显著水平。因此,叶面喷施Si+Ce复合处理在促进水东芥菜生长,降低水东芥菜体内重金属含量以及提高水东芥菜品质等方面的性能要优于单独喷施Si或单独喷施Ce。     

Experimental study on advantages of foam–sol in coal dust control

In China, more than 2.65 million coal mine workers are exposed to coal dust. Every year, new pneumoconiosis cases amount to 25,000, among which 6000 cases die of this disease. The figure is twice the death toll in production safety accidents. Occupational diseases seriously endanger life and health of coal mine workers, and restrict the healthy growth of the coal industry.The paper presented a study of foam–sol-based coal dust control. This was an experimental study of characteristics of foam–sol-based coal dust control, which features dust capture, suppression, and isolation. Comparative wettability experiments were carried out to determine contact angles of water, aqueous foam, and foam–sol solution. A new foam–sol generating system with a conical diffuser outlet was proposed.The experiment results clearly showed that the foam–sol features dust capture, suppression, and isolation. The wettability of the aqueous foam solution was better than the foam–sol solution, but the foam–sol technology had the better ability to capture the airborne dust, suppress the static dust and enclose the dust source, due to the excellent surface viscosity, strong cohesiveness and less volatile property. The paper concluded that the foam–sol could greatly improve the dust control efficiency and did not have main deficiencies that the aqueous foam technology had.     

Preparation methods and thermal stability of Ba-Mn-Ce oxide catalyst for NOx-assisted soot oxidation

Manganese oxide-loaded and -doped ceria as well as the corresponding barium-modified oxide catalysts were prepared for soot oxidation in the presence of NOx, and were characterized by using X-ray diffraction, Brunauer-Emmett-Teller and NO temperatureprogrammed oxidation measurements. The activity of catalyst depended strongly on the NO2 production capacity, and the importance of surface nitrates was weakened without heat transfer limitations. The formation of perovskite-type oxides after the high-temperature calcination caused the loss of NOx storage capacity for the Ba-modified catalysts, but did not seem to affect the NO oxidation activity obviously. The addition of barium did not prevent the phase separation of MnOx-CeO2 solid solutions, whereas it inhibited the sintering of oxide crystallites effectively. This, as well as the relatively high surface area, resulted in a small increase in soot oxidation temperature for the thermally aged Ba/Mn-Ce catalyst.     

二氧化铈纳米催化剂的制备及臭氧化应用

分别以Ce(NO3)3.6H2O和(NH4)2Ce(NO3)6作为铈源,通过简便的化学沉淀法,制备了二氧化铈纳米材料,考察了铈源对所得纳米结构、表面特征的影响。并将纳米材料应用于降解废水用臭氧化催化剂。结果表明,铈源的不同,导致纳米材料的表面态不同,从而引起二者的催化性能具有显著差异。其中,以Ce(NO3)3.6H2O为铈源获得的样品显示了较好的催化活性,以臭氧化反应60 min降解苯酚为例,苯酚降解效率提高了70%,开拓了纳米氧化铈作为臭氧化催化剂的新应用,为臭氧化水处理技术提供了新的选择。     

天然蛋白杂化硅溶胶阻燃棉织物的制备及燃烧性能分析

采用溶胶-凝胶法,以正硅酸乙酯(TEOS)为前驱体、乙醇(C_2H_5OH)为溶剂、盐酸(HCl)为催化剂,1-γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)为偶联剂制备SiO_2单一、复合和明胶(C_(102)H_(151)O_(39)N_(31))杂化溶胶,利用激光粒度仪对溶胶粒径进行测定。采用浸渍-烘焙过程将溶胶后整理棉织物。利用热重分析(TG)、极限氧指数(LOI)、扫描电镜(SEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱分析(FTIR)对整理前后棉织物热解特性、阻燃性能、表面微观形貌、表面元素组成和官能团分布进行测试和表征,探讨明胶杂化溶胶阻燃效应和机理。结果发现:溶胶粒径分布表明纳米SiO_2-KH570-明胶之间发生了化学键紧密结合,缩合生成Si-O-Si和氢键;SEM、FTIR和XPS分析表明具有明胶杂化组分的硅基溶胶在织物表面形成紧密涂层,呈现一定化学结合状态;TG分析表明,该结合状态对热稳定性影响显著,杂化溶胶后整理织物热解残炭率较原始棉织物提高872%,SiO_2-KH570和SiO_2-明胶复合溶胶体系间存在协效性;LOI分析表明,SiO_2-KH570-明胶杂化溶胶阻燃效应最佳,LOI最高为25.2,对应ΔLOI/Δm最高为4.80 g~(-1),SiO_2单一溶胶和明胶及SiO_2-KH570复合溶胶和明胶间体现明显协同效应;明胶可单方面提升SiO_2单一溶胶及SiO_2-KH570复合溶胶的凝胶化效应,促进三维微观骨架涂层结构形成,提升燃烧过程中棉织物脱水成炭作用。     

富氧条件下在Ag/Al2O3催化剂上C3H6选择性还原NO

比较富氧条件下,Ｃ₃Ｈ₆ 在溶胶－凝胶和浸渍２种方法制备的Ａｇ／Ａｌ₂Ｏ₃ 催化剂上还原ＮＯ的活性和热稳定性． 结果表明,从活性角度考虑,采用溶胶－凝胶法制备Ａｇ／Ａｌ₂Ｏ₃ 催化剂时,最佳Ａｇ 负载量（ｗｔ）为４％ ～６％ ,其最大活性与浸渍法制备的２％ Ａｇ／Ａｌ₂Ｏ₃ 催化剂相同,而溶胶－凝胶法制备的催化剂有更宽的活性温度范围． 随着焙烧温度提高,溶胶－凝胶法制备的Ａｇ／Ａｌ₂Ｏ₃ 催化剂的比表面和活性下降比浸渍法慢．此外,还考察了气氛中含有ＣＯ对Ａｇ／Ａｌ₂Ｏ₃ 催化剂活性的影响,结果表明活性降低,其原因可能是活性高的氧化态Ａｇ 被ＣＯ部分还原为活性低的还原态Ａｇ．     

制备方法对Mn-Ce/TiO2催化剂低温选择性催化还原活性的影响

采用溶胶凝胶法、浸渍法以及两者相结合的方法制备了Mn-Ce/TiO2催化剂.运用XRD、BET和SEM等技术对催化剂进行了表征,发现溶胶凝胶法制备的Mn-Ce/TiO2催化剂为锐钛矿结构,具有较大的比表面积,中孔结构丰富,Mn、Ce活性组分在载体表面高度分散或形成了无定形结构.实验研究了催化剂对氨选择性催化还原NO反应的催化性能,结果表明,用溶胶凝胶法制备的Mn-Ce/TiO2催化剂脱硝活性最好,当Mn、Ce负载量为20％,NH3/NO摩尔比为1.1,空速为9 436 h-1,烟气温度为240℃时,NO转化率大于90％.     

B／Y^3＋共掺杂纳米TiO2催化剂的制备及其降解甲醛的光催化性能评价

为了提高室内环境空气质量,本论文开展了光催化剂制备的研究。本论文采用溶胶-凝胶法制备B／Y^3＋共掺杂TiO2复合光催化材料,以甲醛为降解物质,在紫外和可见光下分别研究了复合催化剂的光催化活性,对不同掺杂对光催化活性的影响、光催化剂的稳定性进行了分析。B／Y^3＋共掺杂TiO2复合光催化材料大大提高了催化剂的活性,对甲醛降解有较高的效率。