A method to construct perfect 3D polymer/graphene oxide core–shell microspheres via electrostatic self-assembly

Abstract

ARTICLE This journal isIn this study, a method to construct perfect three-dimensional (3D) polymer/graphene oxide (GO) core-shell microspheres was proposed using the electrostatic self-assembly. 2D GO nanosheets were successfully wrapped onto polymer microsphere to form a perfect 3D coreshell structure with a uniform shell thickness under the action of the electrostatic attraction force. The GO nanosheets with 1.5-2 nm thickness and the area over 2×1 μm 2 were firstly prepared from graphite, and then the cationic polystyrene (PS) microspheres with 0.246% and 0.715% surface concentration of -N(CH 3 ) 3 + were successfully synthesized. After that, PS/GO core-shell microspheres were constructed between GO nanosheets and the cationic PS microspheres. It was found that different cationic PS microspheres leaded to different assembly speed. The SEM and TEM images of rippled silk waves on the surface of PS/GO core-shell microspheres not only indicated the perfect polymer/GO core-shell structure, but also presented a strong binding between two materials. It was also revealed that the thickness of the shell of PS/GO core-shell microspheres was under good control, and the thickness of the shell from different cationic PS microspheres was 9-13 nm and 80-100 nm, respectively. The method proposed here has proved to be a valuable tool for the assembly of 3D microstructures from polymers and graphene oxide (or graphene).

Highly Conductive Transition Metal Carbide/Carbonitride(MXene)@polystyrene Nanocomposites Fabricated by Electrostatic Assembly for Highly Efficient Electromagnetic Interference Shielding

“…After the self‐assembly of the negatively charged Ti 3 C 2 T x on the positively charged PS microspheres, the peak assigned to N(CH 3 ) 3 + greatly decreases and a new peak emerges at 400.5 eV. These changes may be attributed to the decreased electronic density around the N atom upon the electrostatic coordination of Ti 3 C 2 T x to the N(CH 3 ) 3 + group and the neutralization of electronegative O and F groups on Ti 3 C 2 T x with electronic charge from the N element (Figure c) . Consistent with the XPS results, the Ti 3 C 2 T x @PS hybrid presents the characteristic Fourier‐transform IR (FT‐IR) peaks at 3434 and 1630 cm −1 , suggesting its successful assembly, and the peak at 550 cm −1 may be correlated to the deformation vibration of TiO bond (Figure d).…”

“…In addition to the Ti and C components ( Figure a), the presences of O and F groups are also confirmed by the C‐Ti‐T x 2p 3/2 (455.8 eV) and C‐Ti‐T x 2p 1/2 (461.8 eV) peaks in the Ti 2p spectrum (Figure b), which endows Ti 3 C 2 T x with high hydrophilicity and strong negative charges . Meanwhile, C, O, N, and Cl elements are found in the cationic PS microspheres and their N element mainly arises from the DMC molecules grafted on the PS surfaces . At a low content of DMC (2 wt% for styrene) (Figure a), sufficient positive charges are provided for the PS microspheres to induce the assembly of Ti 3 C 2 T x nanosheets …”

“…In the N 1s spectrum, the two peaks at 399.7 and 402.8 eV correspond to CN bond and cationic N(CH 3 ) 3 + species on the PS microspheres, respectively (Figure c) . After the self‐assembly of the negatively charged Ti 3 C 2 T x on the positively charged PS microspheres, the peak assigned to N(CH 3 ) 3 + greatly decreases and a new peak emerges at 400.5 eV.…”

Enhanced properties of poly(styrene–b–ethylene–co–butylene–b–styrene) nanocomposites with in situ construction of interconnected graphene network

“…GO layers had small average dimension (<1 μm) after ultrasonication. Such results clearly indicated graphite oxide had been successfully exfoliated via ultrasonic method . Raman spectroscopy was used to characterize structural changes of carbon materials [Figure (b)].…”

Optical Properties of Composites Based on Graphene Oxide and Polystyrene

“…The interest in these composite materials was reported to be for use as flame retardants [9] and non-volatile memory devices [10]. In the case of the PS/GO composites, the following six synthesis methods were used until now: (i) suspension polymerization [11], (ii) microemulsion polymerization [12], (iii) electrostatic self-assembly [13], (iv) reversible addition fragmentation chain transfer [14], (v) in situ polymerization followed by melt process [15], and Pickering emulsion polymerization [8]. Using X-ray photoelectron spectroscopy (XPS) and IR spectroscopy, the mechanisms proposed for the microemulsion and suspension polymerizations of styrene in the presence of GO were demonstrated to induce: (i) the opening of ether cycles on the GO surface [11] and (ii) the appearance of ester groups [12].…”