Conductive Micropatterns Containing Photoinduced In Situ Reduced Graphene Oxide Prepared by Ultraviolet Photolithography

Abstract

metal nanowires into polymers to improve their conductivity. [3] Among these, graphene has attracted much attention for its high conductivity. [4] Nevertheless, the traditional synthesis methods of graphene are limited by their complexity and low yields. [5] Owing to the strong π-π interaction between graphene layers, the interfacial dispersion between graphene and the polymer is poor, which leads to the easy aggregation of graphene in the polymer. [6] These defects inevitably affect the performance of graphene-based polymers and constrain their extensive applications.Currently, the common strategy adopted by researchers is to replace graphene with GO for combination with polymers. [7] First, GO can be produced on a large scale. Second, GO contains rich oxygencontaining functional groups. Through covalent grafting functionalization with various organic functional groups, GO easily disperses in organic solvents and polymer matrices. [8] Oxygen-containing functional groups, which destroy the path of electron movement, however, result in the conductivity of GO being far lower than that of graphene, which seriously restricts its application. To improve its conductivity, it is essential to find a suitable method to reduce GO. [9] Currently, the common reduction methods for GO are chemical reduction [10] and thermal reduction. [11] While they both take a long time for reduction, reducing agents used in chemical reduction such as hydrazine hydrate are toxic and harmful. Alternatively, photoreduction is a means of reducing GO by irradiation, which has the merits of a mild reduction process, environmental friendliness and short period compared to conventional methods. [12] According to the sequence of reduction, the preparation approaches of RGO/polymers can be divided into ex situ polymerization and in situ poly merization. [13] The former refers to reduction prior to the preparation of the composites, and the latter involves simultaneous reduction during the preparation process. As a result, composites obtained by in situ polymerization have better dispersion and material properties. Xue [14] utilized bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide (XBPO) to reduce GO by UV irradiation and then mixed RGO with SU-8 photoresist to obtain conductive RGO/SU-8 films. His work is ex situ reduction, which means increasing the complexity of the preparation process. Chiappone [15] et al. used 2-hydroxy-2-methyl-1-phenyl-1-acetone (HMPP) as a Herein, one kind of conductive patterned film with high resolution comprised of reduced graphene oxide (RGO) is prepared by the ultraviolet photo lithography technique. RGO working as a conductive filler greatly improves the conductivity of films and is formed through the photoinduced in situ reduction of graphene oxide (GO) added to the photoresist of the patterned films. This photoreduction method is very ecofriendly and efficient with a reduction time of <20 min. Furthermore, the effect of various factors on the conductivity of the films is investigated in detail, and appropriate c...

Introduction of Photopolymerization Technology and Application

“…Our group designed a kind of conductive patterned film with high resolution comprised of reduced graphene oxide (RGO) which prepared by the ultraviolet photolithography technique. [189] This work developed a strategy of introducing GO into the photocuring formula and used UV photolithography technology to create conductive patterned polymer films in one step with high efficiency. BAPO not only acts as a PI to promote the photopolymerization of films under UV irradiation but also serves as a reductant to reduce GO.…”

“…Figure 52 Schematic illustration of the formation of photoresist/RGO composites. [189] Posted on 28 Mar 2023 -The copyright holder is the author/funder. All rights reserved.…”