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A potential approach to enhance the suppressed proton conductivity of nanoscale ultrathin Nafion films is to adjust the ionomer structure via regulating the catalyst–ionomer interaction. To understand the interaction between substrate surface charges and Nafion molecules, self-assembled ultrathin films (∼20 nm) were prepared on the SiO2 model substrates, which were modified with silane coupling agents to carry either negative (COO–) or positive (NH3 +) charges. Specifically, the surface energy, phase separation, and proton conductivity were investigated by contact angle measurements, atomic force microscopy, and microelectrodes to illuminate the relationship between the substrate surface charge, thin-film nanostructure, and proton conduction. Compared to electrically neutral substrates, ultrathin films formed faster on the negatively charged substrate with an 83% increase in proton conductivity but formed more slowly on the positively charged substrate, with proton conductivity decreased by 35% at 50 °C. The surface charges interact with sulfonic acid groups of Nafion molecules to alter molecular orientation, resulting in different surface energies and phase separation, which are responsible for proton conductivity variation.

IntroductionChildhood asthma is globally one of the most common respiratory disorders and accounts for more school absences and more hospitalizations than any other chronic illness. The worldwide economic burden of this disease exceeds those of HIV/AIDS and tuberculosis combined. Proper intervention and effective management is of paramount importance for the control and prognosis of paediatric asthma. Unfortunately, the rate of uncontrolled and partially controlled paediatric asthma in China is >90%. This study will use a new management model to investigate the status of asthma control and the adherence of patients to a medication protocol.MethodsThis prospective, multicentre, observational study will be conducted at 15 hospitals on children (n=800) diagnosed with asthma. Each patient will be assigned to either the nearest community hospital or Shanghai Children’s Medical Center, whichever is closer to the patient’s home, according to the decision of parents. Participants were divided into two groups: tertiary care hospital (Shanghai Children’s Medical Center) follow-up group and community hospital follow-up group. The primary outcome will be the difference in the proportion of controlled, partially controlled and uncontrolled asthma among the two groups. Secondary outcomes will be the differences in adherence rate, lung function, exacerbations, growth development, total asthma-related unscheduled visits, days absent from school and loss of working days for the patient’s caregiver. Data will be analysed on an intention-to-treat and a per-protocol basis.Ethics and disseminationEthics approval was obtained from the Institutional Review Board of Shanghai Children’s Medical Center affiliated with Shanghai Jiao Tong University of Medicine. We plan to publish the results of this study in a peer-reviewed journal article.