Self-passivation/self-delivery/self-healing anticorrosion polymer coating for marine applications.

Corrosion of steel in the marine environment greatly reduces their service life. Polymeric coatings are the most popular anticorrosion technology, but seawater penetration cannot be prohibited because of the distinct stacking structure of the macromolecular chains. In this context, a novel anticorrosive hyperbranched polyurethane-based coating with dopamine (DOPA) at the terminals is prepared herein. The built-in DOPA is able to capture the iron ions released from the corroded substrate and form DOPA-Fe3+ complexation, which further cooperates with the surrounding seawater and imparts self-passivation, self-delivery and self-healing capabilities to the coating. Under the joint action of these measures, the corrosion of tinplate (serving as the steel model) is reduced to a record-low level (corrosion current = 1 × 10-9 A cm-2, corrosion rate = 1 × 10-5 mm year-1). Conceptually, the present dynamic active anticorrosion strategy greatly outperforms the traditional static passive approach, and turns the unfavorable but unavoidable seawater into a favorable factor, which paves the way for the development of long-lasting marine coatings.

Development of a paper-based microfluidic analytical device by a more facile hydrophobic substrate generation strategy.

Microfluidic paper-based analytical devices (µPADs) have a significant potential in developing portable and disposable point-of-care testing (POCT). Herein, a facile, rapid, cost-effective and environment friendly strategy for µPADs fabrication is proposed. Specifically, the substrate paper was hydrophobized by coating with trimethoxysilane (TOS), and then the selected area was hydrophilized by treating with surfactant. The whole fabrication process was implemented within 7 min, with no need for complex pre-treatment, high-temperature and special equipment. As a proof-of-concept application, the as-prepared µPAD was applied to determination of the glucose content in human serum samples. The results agreed well with those obtained by a glucometer. We believe that the µPADs fabrication method proposed here could provide a facile, rapid and low-cost reference for other related studies.