Ji Donghwan, Choi Suji, Kim Jaeyun
School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea.
Department of Health Sciences and Technology, Samsung Advanced Institute for Health Science and Technology (SAIHST), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea.
Small. 2018 Jun;14(26):e1801042. doi: 10.1002/smll.201801042. Epub 2018 May 28.
The fabrication of mechanically superior polymer composite films with controllable shapes on various scales is difficult. Despite recent research on polymer composites consisting of organic matrices and inorganic materials with layered structures, these films suffer from complex preparations and limited mechanical properties that do not have even integration of high strength, stiffness, and toughness. Herein, a hydrogel-film casting approach to achieve fabrication of simultaneously strong, stiff, and tough polymer composite films with well-defined microstructure, inspired from a layer-by-layer structure of nacre is reported. Ca -crosslinked alginate hydrogels incorporated with platelet-like alumina particles are dried to form composite films composed of horizontally aligned alumina platelets and alginate matrix with uniformly layered microstructure. Alumina platelets are evenly distributed parallel without precipitations and contribute to synergistic enhancements of strength, stiffness and toughness in the resultant film. Consequentially, Ca -crosslinked alginate/alumina (Ca -Alg/Alu) films show exceptional tensile strength (267 MPa), modulus (17.9 GPa), and toughness (3.60 MJ m ). Furthermore, the hydrogel-film casting allows facile preparation of polymer composite films with controllable shapes and various scales. The results suggest an alternative approach to design and prepare polymer composites with the layer-by-layer structure for superior mechanical properties.
制备具有各种尺度可控形状且机械性能优异的聚合物复合薄膜是困难的。尽管最近对由有机基体和具有层状结构的无机材料组成的聚合物复合材料进行了研究，但这些薄膜制备过程复杂，机械性能有限，无法同时兼具高强度、高刚度和高韧性。在此，报道了一种水凝胶薄膜浇铸方法，该方法受珍珠层的逐层结构启发，可制备出同时具有高强度、高刚度和高韧性且微观结构明确的聚合物复合薄膜。将掺入片状氧化铝颗粒的钙交联藻酸盐水凝胶干燥，形成由水平排列的氧化铝片晶和具有均匀层状微观结构的藻酸盐基体组成的复合薄膜。氧化铝片晶平行均匀分布且无沉淀，有助于提高所得薄膜的强度、刚度和韧性。因此，钙交联藻酸盐/氧化铝（Ca-Alg/Alu）薄膜表现出优异的拉伸强度（267MPa）、模量（17.9GPa）和韧性（3.60MJ m）。此外，水凝胶薄膜浇铸法可轻松制备具有可控形状和各种尺度的聚合物复合薄膜。结果表明，这是一种设计和制备具有逐层结构以获得优异机械性能的聚合物复合材料的替代方法。
