聚異丁烯胺與奈米碳管控制粗糙度製備超疏水表面

Abstract

隨著科技不斷的進步，物體表面自清潔功能是奈米科技廣為討論的研究課題，透過自然界蓮花效應得到超疏水性自清潔作用機制的基本原理:低表位能的疏水化學物質及粗糙度。奈米碳管物性、化性或材料特性上均有著顯著非凡的表現，由於奈米碳管本身疏水的化學特性，在尺寸上為奈米等級的結構，以奈米碳管作為超疏水的材料在近年以來為熱門研究議題。目前文獻中奈米碳管應用於超疏水特性方面多透過含氟、長烷基鏈等低表位能物質進行化學改質或化學沈積法排列奈米碳管製成具有雙尺寸粗糙度表面，其製程相對較為繁瑣，因此研發出簡單之製程，僅需透過聚異丁烯胺將奈米碳管分散之溶液塗佈於基材上及可製備超疏水之複材薄膜。利用不同莫耳比例之聚異丁烯接枝丁二酸酐共聚物和聚氧丙烯嵌段三胺共聚物反應合成之聚異丁烯胺共聚物衍生物，含有能與奈米碳管管壁產生強非共價作用力之胺基，經過超音波震盪吸附於脫束之獨立奈米碳管上；疏水端聚異丁烯鏈段在有機溶劑中為提供溶解端，能有效的將獨立之奈米碳管經由鏈段造成空間阻礙使其分散於有機溶劑中，製備穩定分散之奈米碳管溶液。將聚異丁烯胺和奈米碳管分散液塗佈於基材上製備之複材薄膜，由於奈米碳管聚集產生之粗糙度及異丁烯胺之低表面能化學特性，使該複材薄膜具備超疏水的特性。而改變奈米碳管與聚異丁烯胺比例形成之複材薄膜，經由粗糙度之差異可操控其表面親疏水特性，有高於160度之接觸角。進一步增強薄膜的強度，聚異丁烯胺可同時當硬化劑與雙酚A二縮水甘油醚型環氧酯樹脂進行硬化反應，製備成強度佳之奈米碳管/聚異丁烯胺/環氧酯樹脂複材薄膜，其結構強韌穩定並在長時間的浸水處理、強酸強鹼之環境下或物理性刮磨依然能保有超疏水之特性。

We report a facile method for preparation of the robust superhydrophobic film by fabricated carbon nanotubes (CNTs) in the matrix of polyamine-cured epoxy nanocomposite. The requisite polyisobutylene-amines (PIB-amine) were prepared from amidation of PIB-succinic anhydride with polyoxypropylene-triamine at various molar ratios The PIB-amines, consisting of multiple amindoacid functionalities and have chemical structures of linear molecule with one PIB terminal, two PIB terminal and branch with three PIB terminal, serve as an intensive noncovalent bonding force for de-bundling CNTs aggregates into individual tubes. The CNTs dispersion was analyzed by UV-vis absorption and transmission electron microscopy (TEM). The finely dispersed CNTs were consequently self-aligned along with the hydrophobic PIB alkyls into micrometer scale of roughness and showed superhydrophobic and self-cleaning phenomenon. The morphology of the align CNTs surface was observed by scanning electron microscopy (SEM) and the result showed the roughness scale is around 1−4 μm. Furthermore, the CNTs dispersion was introduced into diglycidylether of bisphenol-A. Regarded PIB-triamine as a curing agent, the robust polyamine-epoxy nanocomposite can be generated and demonstrated a superhydrophobic property with the measurement of water contact angle up to 160o. The polyamine-epoxy nanocomposite was self-standing and stable against the immersion in water with a wide range of pH and a mechanical scratching. The convenient manipulation of PIB-amine structure, the PIB-amine/CNTs/epoxy nanocomposite and curing conditions may represent an advance for superhydrophobic coating materials that conventionally required CNTs organic modification or fluorinated alkyl compounds as reported in literature.