Modification for Uniform Surface of Nafion Ultrathin Film Deposited by Inkjet Printing

Abstract

A lack of knowledge about the features of Nafion confined to ultrathin films at the interface has motivated additional examinations to promote the performance of polymer electrolyte membrane fuel cells (PEMFCs). In this work, we demonstrated the utilization of practical film-forming technique inkjet printing to fabricate a Nafion ultrathin film less than 10 nm thickness. However, the well-known "coffee-ring" effect caused poor quality of the printed pattern, which has restricted its application. This report describes a systematic investigation of necessary parameters such as ink concentration, substrate type, pitch, and offset for printing processes. Furthermore, post-treatment in an ethanol vapor atmosphere exhibited a significant effect on flattening and homogenizing the film surface morphology. Results show that the well-distributed Nafion ultrathin film modified by ethanol vapor annealing manifested much-improved proton conductivity.

Progress on highly proton-conductive polymer thin films with organized structure and molecularly oriented structure

“…Figure 2(g-j) presents the film thickness dependence of the in-plane proton conductivity on quartz [37], MgO [35,36], sputtered Pt [37], and sputtered Au [36] surfaces. All proton conductivities showed lower values than those of a commercially available Nafion membrane [35,65,66]. This lower proton conductivity is a widely reported result [33,[67][68][69][70].…”

Inkjet and Aerosol Jet Printing of Electrochemical Devices for Energy Conversion and Storage

“…This uniformity results in a nearly three fold increase in peak power density when compared to a similar impregnation attempted with spray painting (Figure ). Enhancing the conductivity of the Nafion layer through optimization of the printing parameters may lead to yet enhanced performance . Simultaneous optimization of the triple phase region's porosity and conductivity may also be possible through inkjet printing …”

Effect of Casting Solvent on Interfacial Molecular Structure and Proton Transport Characteristics of Sulfonated Polyimide Thin Films

“…Recently, structural confinement effects of polymer in nanostructured thin films have been intensively investigated because morphology and chain dynamics of polymer thin films are significantly affected by surfaces and substrate interface. [5][6][7][8][9][10][11][12][13] The confinements in thin films induce preferred chain packings and molecular orientations along the in-plane or out-of-plane direction from a substrate plane by self-assembly, which exhibits the highly organized ion-conducting channels that possibly lead to the change of transport characteristics. [14][15][16][17][18][19] Therefore, the organized structure has attracted considerable interest for high proton conduction in thin films.…”