Sandwich‐Type Nanocomposite of Reduced Graphene Oxide and Periodic Mesoporous Silica with Vertically Aligned Mesochannels of Tunable Pore Depth and Size

• Published in: Advanced functional materials 2017-12, Vol.27 (47), p.n/a
• Main Authors: Wang, Zheng‐Ming, Peng, Wenqin, Takenaka, Yoshiko, Yoshizawa, Noriko, Kosuge, Katsunori, Wang, Wendong, Ozin, Geoffrey A.
• Format: Article
• Language: English
• Subjects: Alignment; Graphene; Materials science; nanocomposite; Nanocomposites; periodic mesoporous silica; pore depth and size control; Pore size; Porosity; Reaction time; Ripening; Silica; Silicon dioxide; Small angle X ray scattering; Surfactants; Synchrotron radiation; Synthesis; Tetraethyl orthosilicate; vertically aligned
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201704066

Sandwich‐type nanocomposites of graphene oxide (GO) and periodic mesoporous silica (PMS) with vertically aligned mesochannels of different pore depth and size are synthesized and characterized, and their formation modes are examined. The existence of mesoscale ordered structure in the mixture of GO and surfactant solutions is confirmed for the first time by in situ small angle X‐ray scattering measurement using synchrotron radiation. The mesochannel depth and pore wall ripening of PMS in the nanocomposites are controlled by the reaction time of the hydrolysis of tetraethyl orthosilicate. The pore size of PMS in the nanocomposites can be varied in the range of 1–5 nm by varying the chain length of alkyltrimethylammonium (CnTA+) template and high specific surface area (≈1000 m2 g−1) is achieved for all samples. Nanocomposites with vertically aligned PMS mesochannels can be synthesized by applying CnTA+ templates of n ≥ 12, whereas with CnTA+ of n ≤ 10, either PMS nanoparticle deposited GO structure or the structure with incomplete coverage of GO surface with imperfect PMS is found. The aggregation behaviors of surfactant molecules on GO depend on surfactant concentration relative to critical micelle concentration and reaction temperature, and result in the peculiar nanocomposites of different structural styles. Vertically aligned mesochannel depth and size of sandwich‐type nanocomposites of reduced graphene oxide (GO) and periodic mesoporus silica can be tailored by tuning synthesis conditions and alkyl chain length of CnTA+ templates, whose formation mode is examined by the high photon flux SAXS technique and zeta‐potential‐based solution chemistry of surfactant and GO mixtures.