title: Dependency of Nanodiamond Particle Size and Outermost-Surface Composition on Organo-Modification: Evaluation by Formation of Organized Molecular Films and Nanohybridization with Organic Polymers.
abstract: The formation behavior of organized organo-modified nanodiamond films and polymer nanocomposites has been investigated using nanodiamonds of several different particle sizes and outermost-surface compositions. The nanodiamond particle sizes used in this study were 3 and 5 nm, and the outermost surface contained -OH and/or -COOH groups. The nanodiamond was organo-modified to prepare -OH2+cations and -COO-anions on the outermost surface by carboxylic anion of fatty acid and long-chain phosphonium cation, respectively. The surface of nanodiamond is known to be covered with a nanolayer of adsorbed water, which was exploited here for the organo-modification of nanodiamond with long-chain fatty acids via adsorption, leading to nanodispersions of nanodiamond in general organic solvents as a mimic of solvency. Particle multilayers were then formed via the Langmuir-Blodgett technique and subjected to fine structural analysis. The organo-modification enabled integration and multilayer formation of inorganic nanoparticles due to enhancement of the van der Waals interactions between the chains. Therefore, "encounters" between the organo-modifying chain and the inorganic particles led to solubilization of the inorganic particles and enhanced interactions between the particles; this can be regarded as imparting a new functionality to the organic molecules. Nanocomposites with a transparent crystalline polymer were fabricated by nanodispersing the nanodiamond into the polymer matrix, which was achievable due to the organo-modification. The resulting transparent nanocomposites displayed enhanced degrees of crystallization and improved crystallization temperatures, compared with the neat polymer, due to a nucleation effect.
authors.affiliation: Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Taira
authors.initials: T
authors.lastname: Tasaki
authors.affiliation: Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Qi
authors.initials: Q
authors.lastname: Meng
authors.affiliation: Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Muhammad Abdullah Al
authors.initials: MAA
authors.lastname: Mamun
authors.affiliation: Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kasahara
authors.affiliation: Graduate School of Science and Engineering, Tokyo Institute of Technology , Ookayama 2-12-1, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Akasaka
authors.affiliation: Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Atsuhiro
authors.identifier: http://orcid.org/0000-0002-2503-8529
authors.initials: A
authors.lastname: Fujimori
keywords: nanodiamond; organo-modification; polymer/nanodiamond nanocomposite; single-particle layer; surface treatment