An efficient method for the polymer modification of gibbsite (gamma-Al(OH)(3)) nanoplatelet particles with poly(methyl methacrylate) (PMMA) by surface-initiated atom transfer radical polymerization (SI-ATRP) was developed. A newly developed initiator system based on 12-(2-bromoisobutyramido) dodecanoic acid (BiBADA) enable grafting densities in excess of 0.4 nm(-2) with minimal amount of free homopolymer impurities and narrow molecular weight distribution. The gibbsite brush nanoplatelets were shown to organize into transparent films with nacre-like lamellae morphology. A significant increase of the glass transition temperature (as compared to pristine PMMA) was observed and attributed to the increase of steric confinement in planar brush architectures. The applicability of the presented methodology to a wide range of ATRP-compatible chemistries could be a basis for the development of novel functional materials in which properties depend on the directionality of brush nanoplatelet orientation and interaction. (C) 2017 Elsevier Ltd. All rights reserved.