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Surfactants are frequently employed in the fabrication of polymer/graphene-based nanocomposites via emulsion techniques. However, the impact of surfactants on the electrical and mechanical properties of such nanocomposite films remains to be explored. We have systematically studied the impact of two anionic surfactants [sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS)] on intrinsic properties of the nanocomposite films comprising reduced graphene oxide in a matrix of poly(styrene-stat-n-butyl acrylate). Using these ambient temperature film-forming systems, we fabricated films with different concentrations of the surfactants (1–7 wt %, relative to the organic phase). Significant differences in film properties were observed both as a function of amount and type of surfactant. Thermally reduced films exhibited concentration-dependent increases in surface roughness, electrical conductivity, and mechanical properties with increasing SDS content. When compared with SDBS, SDS films exhibited an order of magnitude higher electrical conductivity values at every concentration (highest value of ∼4.4 S m–1for 7 wt % SDS) and superior mechanical properties at higher surfactant concentrations. The present results illustrate how the simple inclusion of a benzene ring in the SDS structure (as in SDBS) can cause a significant change in the electrical and mechanical properties of the nanocomposite. Overall, the present results demonstrate how nanocomposite properties can be judiciously manipulated by altering the concentration and/or type of surfactant.

To ease the shortage of professionals, lay volunteers were trained to become health promoters and role models for a large community program to enhance physical activity, well-being, and neighborhood cohesion in socioeconomically disadvantaged groups in Hong Kong. This study aimed to examine the effects on health promoters (trainees) and the feasibility and acceptability of capability-building train-the-trainer workshops (TTTs) using Zero-time Exercise (ZTEx) to implement a community program for about 1,000 participants. A four-session (totally 8 hours) TTT introduced an evidence-based ZTEx intervention to enhance physical activity and well-being, and build capacity for community program implementation. Twenty-eight trainees actively participated in the TTT. Twenty-five and 21 trainees completed the 1- and 3-month questionnaires, respectively. Eleven trainees attended the 1-year focus group interview. Repeated measures analysis of variance and Friedman test were used to compare the parametric and nonparametric data, respectively. Qualitative data were analyzed using thematic content analysis. The trainees reduced their sedentary behavior and improved their interpersonal communication skills, knowledge, and attitude toward ZTEx, grip strength, balance, and perceived well-being. The community participants reported improvements in neighborhood cohesion and grip strength. The 1-year qualitative results supported the 3-month quantitative findings. This brief and innovative TTT affirmed the feasibility of using ZTEx and the role modeling approach for lay health promoters to reduce sedentary behavior and enhance physical activity, fitness, and well-being. They then contributed to the successful implementation of community programs that benefited many. This study provides a new model for building capacity for health promotion in the community.Brief (8-hour) training on lay health promoters using zero time exercise and role modeling to implement a large community program benefited trainees and program participants.