RESUMO
Integrated fabrics with a smart heating control system (HCS) are attractive in warming and thermotherapy for human healthcare management. Metal nanofibers (NFs) networks with high flexibility, conductivity and gas permeability are ideal functional materials for wearable electronics. Herein, a novel sandwich-structural (Ag NFs/fabrics/Pt NFs) textile for a HCS is constructed, where a Ag NF network film was functioned as a wearable heater and Pt NF network arrays were functioned as wearable temperature sensors. Conductivity and mechanical stability of the metal NFs were enhanced by crosslinking the free-standing fiber networks, resulting in high thermo-stability, thermal resistance (163.5 °C W-1 cm2) and temperature sensitivity (0.135% °C-1) of the HCS. The HCS can simultaneously realize heating and temperature distribution detection, demonstrating only 0.57% average error between the simulated resistance-to-temperature diagram of Pt NF arrays and actual temperature mapping. In addition, the HCS can be stuck on the skin for thermochromic fabrics, real-time heating and temperature detection/control through a Bluetooth device in a smartphone wirelessly.
RESUMO
Biological nanochannels control the movements of different ions through cell membranes depending on not only those channels' static inherent configurations, structures, inner surface's physicochemical properties but also their dynamic shape changes, which are required in various essential functions of life processes. Inspired by ion channels, many artificial nanochannel-based membranes for nanofluidics and biosensing applications have been developed to regulate ionic transport behaviors by using the functional molecular modifications at the inner surface of nanochannel to achieve a stimuli-responsive layer. Here, the concept of a dynamic nanochannel system is further developed, which is a new way to regulate ion transport in nanochannels by using the dynamic change in the curvature of channels to adjust ionic rectification in real time. The dynamic curvature nanochannel-based membrane displays the advanced features of the anomalous effect of voltage, concentration, and ionic size for applying simultaneous control over the curvature-tunable asymmetric and reversible ionic rectification switching properties. This dynamic approach can be used to build smart nanochannel-based systems, which have strong implications for flexible nanofluidics, ionic rectifiers, and power generators.
RESUMO
The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gases and liquids under a steady-state applied pressure, nearly eliminate fouling, and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores' deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles.