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[Display omitted] • Atomic layer deposition technic was used to modify protein-based fibers. • ZnO nano film was controllably deposited on the surface of silk fabrics. • Modified silk had antibacterial properties while preserving favorable properties. As a natural protein resource, silk has been favored for thousands of years due to remarkable properties and the lustrous appearance. The broaden use of natural silk promotes it to become a high-tech fiber, which is undesirably hindered by the high hygroscopicity that provides conditions for bacterial growth thus accelerates the corrosion of silk. Functional surface modification can pose as compensation, but traditional nanoscale coating approaches come at the expense of inherent properties. In this work, ultrathin zinc oxide (ZnO) was uniformly deposited on silk fabrics in nanoscale using the atomic layer deposition (ALD) strategy. Different layers of ZnO were deposited by controlling the deposition cycles in the ALD process to evaluate the influences in antibacterial performances. The ZnO coated silk fabrics showed neglectable differences in morphologies compared with the raw silk fabric while manifesting excellent antibacterial properties against E. coli and S. aureus. The ZnO layer had insignificant influence on mechanical and air permeable properties, which guaranteed the wearable properties of silk fabrics. This work contributes to an innovative modification method for natural and wearable protein fibers with antibacterial properties in a controllable and uniform way. [ABSTRACT FROM AUTHOR]

In the next generation power electronics packaging, sinter Ag joining technology has become popular for use as a die attach and is receiving greater attention. Herein, it is reported that sinter Ag particles joining performed directly on a bare Cu substrate coated by a single-layer graphene can provide satisfactory interfacial oxidation protection and mechanical reliability. The shear strength obtained in our research achieved 25.4 MPa in low temperature, pressure-free sintering in air. The Cu oxide layer appeared solely at the location of Cu grain boundaries during sintering and was much smaller than when performed on substrates without graphene coating. The bonding mechanism was realized by Ag nanoparticles (AgNPs) self-generated from the Ag paste during the sintering process which tightly bonded to the graphene surface upon interacting with the Cu oxide. A subsequent high temperature (250 °C) aging test demonstrated that die shear strength maintains its value as-sintered for 750 h. Furthermore, the thickness of Cu oxide with graphene coating was about one fourth of that without graphene and this difference increased with aging time. This study puts forward an exciting solution for sinter Ag joining directly on Cu-based substrates in high temperature for longer lifetime in power electronic packaging applications. Unlabelled Image • Ag sinter joining was conducted on bare Cu covered by single-layer graphene. • In suit formed Ag nanoparticles tightly bonded to the graphene surface. • The thickness of Cu oxide with graphene coating was much smaller that without graphene. • Single-layer graphene provided satisfactory interfacial oxidation protection and mechanical reliability. [ABSTRACT FROM AUTHOR]