【作者】 陈猛；

【导师】 吴也凡；

【作者基本信息】 景德镇陶瓷学院 ， 材料学， 2009， 硕士

【摘要】 不对称的陶瓷膜具有在微米级的支撑体上被纳米晶粒覆盖的通透性结构,它与“自清洁性”的动植物的超疏水表面具有相似的结构。这样就可从仿生学的角度研究陶瓷膜。在无机微滤膜的分离过程中,根据筛分原理,一般认为膜的过滤阻力主要集中在顶膜上,而过滤介质与膜的相互作用过程则往往被忽略。本文研究了具有类荷叶结构的仿生无机微滤膜（含纳米晶涂层修饰改性）与过滤介质水的相互作用。1、关于涂层中ZrO₂纳米晶与过滤介质水的相互作用本研究用四方相ZrO₂纳米晶对α-Al₂O₃无机微滤膜进行了涂层修饰改性,纳米晶改性涂层的表面粗糙度（Ra=6.11μm）明显高于未改性的（1.5μmα-Al₂O₃粉体）表面粗糙度（Ra=0.54μm）,其表面粗糙度的比值为11.32,纳米晶涂层改性膜的比表面积是未改性膜的13.87倍。ZrO₂的晶粒越小其表面积也就越大,表面羟基的数量也就越多,表面羟基电离时所呈现出的负电荷也就越高,其Zeta电位的绝对值也就越大,等压下的水通量也就越大。在世界上首次发现:由于无机微滤膜的顶膜对水的团簇结构的解体作用（过膜后的水的电导率产生突跃性大幅度的增加）,经纳米晶涂层修饰改性后的无机微滤膜在平均孔径相对于支撑体缩小约10倍以后,在相同压差下其水通量不但没有大幅度地减少,反而明显大于支撑体的水通量。正确解释这一看来似乎违背筛分原理的反常现象有可能导致自然界中一些基本规律的发现。2、关于无机微滤膜微孔道内壁的亲、疏水性与过滤介质水的相互作用随着无机微滤膜微孔道内壁的亲水性的下降和疏水性的增强,水的渗透通量呈明显的下降趋势。当达到一定的疏水程度后,水的渗透通量趋近于零。无机微滤膜材质的亲水程度与水通量有着内在的联系。3、不同离子的吸附状态对水通量的影响分别在MgCl₂和NaCl稀溶液中,用AFM研究了四方相ZrO₂纳米涂层的表面排斥力随作用距离的相互关系,Mg²⁺在ZrO₂纳米涂层表面具有特征吸附,为强烈的短程排斥力。Na⁺呈现出惰性电解质的特征,表现为长程排斥力。Mg²⁺在膜表面的特征吸附,使渗透通量呈下降的趋势。而Na⁺的非特征吸附却使水通量呈稍有增大的趋势。4、SnO₂纳米晶涂层（含掺杂或掺入）与过滤介质水的相互作用分别采用镍、银、铜、钛、铁等过渡金属离子,以不同的掺杂（入）量对微米ZrO₂颗粒表面上的SnO₂纳米晶进行掺杂,研究了改性微滤膜的润湿性和水通量随过渡金属离子掺杂量的变化规律。结果表明,以镍、银、铜、钛、铁掺杂的SnO₂纳米涂层对微滤膜进行修饰改性后,其润湿性和水通量都分别有所提高。更多还原

【Abstract】 Asymmetric ceramic membrane has the per-foliate structure with the micron- level support was covered by nano-crystal, which is similar with the structure of the "self-cleaning" super-hydrophobic surface of animal and plant. Thus ceramic membrane is studied in the method of bionics. In the separation process of inorganic micro-filtration membrane, it was thought the filtration resistance of ceramic membrane was concentrated on the top layer of membrane according of the screening principle, and it was usually ignored the interaction between membrane and filter media. In this paper the influence was studied the interaction between the bionic inorganic micro-filtration membrane （including nano-crystalline coating modification） with the similar-lotus-leaf structure and water as filter media.1. The interaction between ZrO₂ nano-crystal of the coating and water as filter media.It is studiedα-Al₂O₃ inorganic micro-filtration membrane was modified by tetragonal ZrO₂ nano-crystal with the surface-roughness of 6.11μm （Ra=6.11μm）, which was higher than the surface-roughness of membrane without modification （Ra=0.54μm） and the ratio of the surface roughness is 11.32. The specific surface area of membrane increase 13.87 times fore-and-aft modification. The smaller the ZrO₂ nano-crystal, the bigger the specific surface area and the more the number of surface hydroxyl and the higher the negative charge due to surface hydroxyl ionization and the larger the absolute value of Zeta potential and the higher the water flux under the same pressure. It is first found in the world: since the disintegration of cluster structure of water effected by the top layer of micro-filtration membrane （the water conductivity sharply increased）, and the aperture of the membrane modified by the nano-crystalline coating reducing by 10 times compare to the membrane supports, the water flux of the modified membrane increased under the same pressure. The correct interpretation of these illegitimacy phenomena to be contrary to screening principles leads to the some basic laws discovery of nature.2. The hydrophilic and hydrophobic properties of microspore of inorganic micro-filtration membrane and the interaction between the pore inner-wall between and water as filter mediaAs the enhancement in hydrophobicity and decrease in hydrophilicity of inorganic micro-filtration membrane pore inner wall, the permeation flux of water showed a decreased trend obviously. The permeation flux of water is closed to zero, when it got to a hydrophobicity point. The hydrophilic degree of micro-filtration membrane’ material associated with the water flux.3. Effect of the different ions’ adsorption on water flux. The relationship of the surface repulsive force of tetragonal ZrO₂ nanocrystalline coating with the effect range was studied by AFM in the dilute solution of MgCl₂ and NaCl. Mg²⁺ was adsorbed on ZrO₂ nano-crystal coating surface, which exhibited the intensive short-range repulsive force. Na⁺ showed the characteristic of inert electrolyte, which exhibited the long-range repulsive force. The characteristic adsorption of Mg²⁺ on membrane surface induced the decrease of permeation flux. And the non-characteristic of adsorption of Na⁺ induced the increase of permeation flux.4. The interaction between SnO₂ nano-crystal coating （include doping or mixture） and water as filter media.SnO₂ nano-crystals loading in the ZrO₂-micron particles were doped by the transition metal ions such as Ni、Ag、Cu、Ti、Fe in different amount. The rule of the wetting-ability of modified micro-filtration membrane and the water flux of membrane doped amount by transition metal ion was studied. The results showed the modified micro-filtration membrane by Ni、Ag、Cu、Ti、Fe doped SnO₂ nano-crystal, which exhibited the wetting-ability and the water flux increasing.更多还原