Aqueous Solution Process

Abstract

Research and development in the field of material science is aiming for further advancements, and expectations in the joining of materials and composite technology are progressively increasing. In particular, a new concept proposed for the control of interface phenomena with the aim to combine materials that are difficult to bond and composite has been attracting increasing interest. This concept has been accelerating progress in the interdisciplinary research area of material development. In this study, joining and compositing of various materials are carried out by precisely controlling the crystal growth and the interface phenomenon in an aqueous solution. Although joining of certain materials has been difficult in the past, these materials are now held together in nano- or micro-sized regions in order to control the microstructure (Masuda et al, Bull Ceram Soc Jpn 49(5):356–360, 2014; Masuda, Bull Ceram Soc Jpn 47(12):929–934, 2012). In particular, a composite structure of a tin oxide (SnO₂) nanosheet assembly and a polymer material is prepared. Oxide materials, such as tin oxide, have been synthesized by high-temperature firing on the order of several hundred degrees and faced many difficulties in bonding and compositing the tin oxide structure to the surface of the polymer material with low heat resistance. Using the proposed method, synthesis of tin oxide crystals can be realized at ordinary temperatures by determining a suitable condition for tin oxide crystallization in an aqueous solution, thereby facilitating bonding with the polymer. In the aqueous solution, nucleation of tin oxide and crystal growth is controlled on the substrate surface to form a nanostructure. Furthermore, crystal growth in SnO₂ is precisely controlled to form a tin oxide nanosheet, and an integrated structure composed of tin oxide nanosheets is synthesized. Moreover, the principle of this method can be applied to control the crystal growth and nanostructure in other materials. The wide applications of this method contribute to the development of various composite materials, and further progress in research on the interface phenomena of　different materials is expected. We aim to develop a method to join different materials, control their nano/microstructure, and achieve patterning (Masuda et al, Bull Ceram Soc Jpn 49(5):356–360, 2014; Masuda, Bull Ceram Soc Jpn 47(12):929–934, 2012). Particularly, a composite material consisting a SnO₂ nanosheet assembly and a polymer film is developed via crystal growth in the aqueous solution.