疏水

Abstract(#br)Four polydimethylsiloxane (PDMS) coatings with different surface free energies have been prepared and applied to smooth and roughened aluminum plates to form hydrophobic and superhydrophobic surfaces. Their surface wettability in terms of water contact angle (CA), sliding angle (SA) and water droplet impact dynamics was studied under an ambient (50% relative humidity, RH at 25\u003cce:hsp sp=\"0.25\"/\u003e°C) and three different condensing environments (low, highly and extremely condensing, i.e. 30%, 60% and 90% RH at −10\u003cce:hsp sp=\"0.25\"/\u003e°C).

Transparent, hydrophobic hybrid films were deposited on glass substrate from solution containing hydroxyl-terminatedpolydimethylsiloxane (PDMS) and TiO2 sol by using a dip coating method. The effects of the film heat-treatment temperatureand PDMS/TiO2 component on surface properties of the hybrid films were investigated by water drop contact angle measurement,and by atomic force microscopy (AFM) and scanning electron microscope (SEM) analyses.

Transparent, hydrophobic hybrid films were deposited on glass substrate from solution containing hydroxyl-terminatedpolydimethylsiloxane (PDMS) and TiO2 sol by using a dip coating method. The effects of the film heat-treatment temperatureand PDMS/TiO2 component on surface properties of the hybrid films were investigated by water drop contact angle measurement,and by atomic force microscopy (AFM) and scanning electron microscope (SEM) analyses.

超疏水现象普遍存在于自然界中，木材也可以通过表面的特定加工获得疏水性，如构建微尺度粗糙表面或用低表面能材料进行装饰等。本研究在不破坏木材原有结构的前提下，考察了木材表面疏水层的形成。用四氢呋喃将正硅酸盐和聚苯乙烯渗透到中空介孔微球结构中，制备了核壳结构粒子。用聚二甲基硅氧烷( PDMS )树脂层包复一个木材样品，增强纳米和微米中空介孔微球在其表面的附着力。根据自然界中超疏水主体的表面结构，将纳米和微米中空介孔微球以不同比例多次喷涂，形成疏水表面。水接触角可达150 °，表明纳米和微米中空介孔微球涂层均实现了疏水行为。利用扫描电子显微镜对木材样品的微观结构进行了检测，利用傅里叶变换红外光谱对化学官能团进行了考察，均验证了疏水性表面包复成功。热重分析表明疏水性木材的热稳定性有所改善。采用划痕试验测试了纳米和微米中空介孔微球涂层在木材表面的耐磨性。结果表明，纳米和微米中空介孔微球涂层是制备极疏水性木制品的有效方法。

超疏水现象普遍存在于自然界中，木材也可以通过表面的特定加工获得疏水性，如构建微尺度粗糙表面或用低表面能材料进行装饰等。本研究在不破坏木材原有结构的前提下，考察了木材表面疏水层的形成。用四氢呋喃将正硅酸盐和聚苯乙烯渗透到中空介孔微球结构中，制备了核壳结构粒子。用聚二甲基硅氧烷( PDMS )树脂层包复一个木材样品，增强纳米和微米中空介孔微球在其表面的附着力。根据自然界中超疏水主体的表面结构，将纳米和微米中空介孔微球以不同比例多次喷涂，形成疏水表面。水接触角可达150 °，表明纳米和微米中空介孔微球涂层均实现了疏水行为。利用扫描电子显微镜对木材样品的微观结构进行了检测，利用傅里叶变换红外光谱对化学官能团进行了考察，均验证了疏水性表面包复成功。热重分析表明疏水性木材的热稳定性有所改善。采用划痕试验测试了纳米和微米中空介孔微球涂层在木材表面的耐磨性。结果表明，纳米和微米中空介孔微球涂层是制备极疏水性木制品的有效方法。

为克服耐水性差的缺点，采用端羟基聚二甲基硅氧烷( PDMS )疏水改性氯氧镁( MOC )水泥，以过氧化氢为发泡剂制备MOC水泥泡沫。扫描电子显微镜( SEM )图像显示，MOC水泥泡沫中含有尺寸在150 ~ 600  μm的可见孔隙，孔径随发泡剂用量的增加而增大。气孔中观察到大量针状的5相，赋予材料强度。孔隙率分析表明，发泡剂的加入增加了孔隙率，增大了孔隙，使材料变得不致密。孔隙率和孔径的增加显著降低了导热系数，从而改善了MOC水泥泡沫的隔热性能。PDMS的改性不仅增强了其耐水性，而且实现了MF-1的超疏水，同时具有相对较大孔隙的样品也具有较好的疏水能力。采用X射线衍射( XRD )和傅里叶变换红外光谱( FTIR )对样品进行分析，从微观角度解释了耐水性增强的机理。