• 文献标题:   High- versus Low- Quality Graphene: A Mechanistic Investigation of Electrografted Diazonium- Based Films for Growth of Polymer Brushes
  • 文献类型:   Article
  • 作  者:   LILLETHORUP M, KONGSFELT M, CECCATO M, JENSEN BBE, JORGENSEN B, PEDERSEN SU, DAASBJERG K
  • 作者关键词:   graphene, aryldiazonium, electrografting, defect, polymer brushe
  • 出版物名称:   SMALL
  • ISSN:   1613-6810 EI 1613-6829
  • 通讯作者地址:   Aarhus Univ
  • 被引频次:   19
  • DOI:   10.1002/smll.201301915
  • 出版年:   2014

▎ 摘  要

Electrografting using aryldiazonium salts provides a fast and efficient technique to functionalize commercially available 3-5 layered graphene (vapour-deposited) on nickel. In this study, Raman spectroscopy is used to quantify the grafting efficiency of cyclic voltammetry which is one of the most versatile, yet simple, electrochemical techniques available. To a large extent the number of defects/substituents introduced to the basal plane of high-quality graphene by this procedure can be controlled through the sweeping conditions employed. After extended electrografting the defect density reaches a saturation level (approximate to 10(13) cm(-2)) which is independent of the quality of the graphene expressed through its initial content of defects. However, it is reached within fewer voltammetric cycles for low-quality graphene. Based on these results it is suggested that the grafting occurs (a) directly at defect sites for, in particular, low-quality graphene, (b) directly at the basal plane for, in particular, high-quality graphene, and/or (c) at already grafted molecules to give a mushroom-like film growth for all films. Moreover, it is shown that a tertiary alkyl bromide can be introduced at a given surface density to serve as radical initiator for surface-initiated atom transfer radical polymerization (SI-ATRP). Brushes of poly(methyl methacrylate) are grown from these substrates, and the relationship between polymer thickness and sweeping conditions is studied.