Acorn‐Shape Polymeric Nano‐Colloids: Synthesis and Self‐Assembled Films

Abstract

These studies show for the first time that the synthesis of two distinct phase-separated copolymers within one colloidal particle, i.e., poly(methyl methacrylate) (PMMA)/n-butylacrylate (nBA) and poly(nBA)/pentafluorostyrene (p-PFS) phases, results in unique acorn-shaped morphologies and are capable of coalescence. Spectroscopic and morphological analysis combined with contact angle measurements as well as thermodynamic modeling reveal that in an effort to create stable heterogeneous two-phase particle morphologies it is essential to provide desirable interfacial energetic conditions during polymerization and to utilise monomers that have a similar glass transition temperature (T(g) ). Such colloidal particles are stable and are able to self-assemble during coalescence, depending upon the surface energy of a substrate. When a particle monolayer coalesces on a high surface tension substrate, the p-PFS phase expresses itself near the film-air interface, whereas for low surface energy substrates, the p-PFS phase dominates the film-substrate interfacial regions.

Recent advances with anisotropic particles

“…2) [17][18][19], and thus, a broad range of investigations has been focused on the fabrication of non-spherical colloidal particles as well as the evaluation of their biomedical implications [18][19][20][21][22]. Preparation of asymmetric micro-and nanoparticles, such as rods, disks, fibers, tubes, dumbbell-shapes, acornshapes, sheets and ellipsoids [5][6][7][8][9][10][11][12][13][23][24][25][26], have been realized by a myriad of different fabrication processes.…”

A temperature-controlled method to produce Janus nanoparticles using high internal interface systems: Experimental and theoretical approaches

“…They can be used in many applications such as nanosensors and nanoprobes [8][9][10], targeted drug delivery [11], as emulsifiers [12][13], etc. Accordingly, Mirsa and Urban proposed a new approach to produce Janus-type acorn-shaped latexes with poly(methyl methacrylate)/poly(butyl acrylate) (PMMA/PnBuA) and PnBuA/pentafluorostyrene (p-PFS) phase via semi-batch emulsion polymerization [14][15]. DeSimone's group developed a comprehensive method for stepwise deposition of phases within cylindrical molds [16].…”

PLGA-Encapsulated Perfluorocarbon Nanoparticles for Simultaneous Visualization of Distinct Cell Populations by 19 F MRI

“…Electron micrographs of the PFCE particles ( Figure 1C), show that the particles generally have a uniform spherical morphology; although some particles show a slight depression or dent. This has been observed in other constructs [22][23][24], and could arise from the peculiar properties of the PFC, suggesting a phase separation in the particles [25]. The formulation process can be carried out using standard lab equipment, and in a cleanroom environment for clinical use.…”