Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates

Abstract

SummaryA novel and facile method was developed to produce hybrid graphene oxide (GO)–polyelectrolyte (PE) capsules using erythrocyte cells as templates. The capsules are easily produced through the layer-by-layer technique using alternating polyelectrolyte layers and GO sheets. The amount of GO and therefore its coverage in the resulting capsules can be tuned by adjusting the concentration of the GO dispersion during the assembly. The capsules retain the approximate shape and size of the erythrocyte template after the latter is totally removed by oxidation with NaOCl in water. The PE/GO capsules maintain their integrity and can be placed or located on other surfaces such as in a device. When the capsules are dried in air, they collapse to form a film that is approximately twice the thickness of the capsule membrane. AFM images in the present study suggest a film thickness of approx. 30 nm for the capsules in the collapsed state implying a thickness of approx. 15 nm for the layers in the collapsed capsule membrane. The polyelectrolytes used in the present study were polyallylamine hydrochloride (PAH) and polystyrenesulfonate sodium salt (PSS). Capsules where characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and Raman microscopy, the constituent layers by zeta potential and GO by TEM, XRD, and Raman and FTIR spectroscopies.

Hybrid poly(allylamine hydrochloride)–graphene oxide microcapsules: preparation, characterization and application in textiles with controlled release behavior

“…Here, the D-band was attributed to the structural disorder and defects induced on the sp 2 hybridization, while the G-band represented the planar configuration of the sp 2 bonded carbon that constitutes GO. 38,39 The peaks at 1000-1100 cm À1 can be assigned to the SQO stretching on PSS. 40…”

Recent Advances in Layer-by-Layer Assembled Conducting Polymer Based Composites for Supercapacitors

“…However, this method did not draw significant interest until the early 20th century Decher and his coworkers established and reintroduced the concept [44][45][46]. Their pioneering work on sequential adsorption of polyelectrolytes on a charged surface triggered a high number of studies on this method later on [33,[47][48][49]. Traditionally, the fundamental principle of this approach is depositing the alternative layer of oppositely charged polyelectrolytes commonly referred to as polyanion and polycation onto a charged solid or flexible substrate surface via electrostatic interaction.…”

Modulation of the internal structure and surface properties of natural and synthetic polymer matrices by graphene oxide doping

“…Graphene oxide (GO) is a single‐layer material with various oxygen‐containing groups (mainly epoxy and hydroxyl groups) that enable attractive properties like extreme thickness and smoothness, strong mechanical strength, high specific surface area, optical transmittance etc. Since the discovery of graphene and its functionalized derivative graphene oxide, hybrid PEM/GO films have attracted considerable attention due to their fascinating properties and fields of application, for example, in nanocapsules for drug‐delivery, sensors with ultrahigh sensitivity, photoconductive films for microelectronic fabrication, hybrid transparent films with controllable conductivity and improved gas‐barrier and mechanical properties . Therefore, knowledge of the factors that control the properties of PEM/GO films is indispensable for fabrication of films for specific applications.…”