Search

The TiO2/TPU fiber shows excellent mechanical and photocatalytic performance, which opens a new avenue to overcome the separation and recovery problems from solutions during practical applications of nanostructured catalysts.

The tensile mechanical properties of carbon nanotube (CNT) fiber, which is a one-dimensional assembly of ultra-strong CNTs, are still far short of our expectations. This is mainly due to their high porosity and relatively weak intertube load transfer efficiency. Previous studies have demonstrated that the fiber strength can be enhanced by the infiltration of polymer chains into the fiber. In this work, polyvinyl alcohol (PVA) was pre-infiltrated into loosely packed CNT ribbons, and the composite ribbons were then densified into the fiber form. This enabled a homogeneous dispersion of polymer chains within the CNT fibers. To enhance the mechanical properties of the CNT/PVA composite fibers, isothermal crystallization and ultrasonic treatments were implemented to increase the crystallization of PVA in the ribbon, and the composite fibers were hot-stretched to improve the alignment of both CNTs and PVA chains within the fibers. It was found that the tensile strength and modulus of the final composite fiber were 210% and 193.6% higher than those of the pristine CNT fiber. The structural evolution during these treatments and the mechanism of fiber strengthening were systematically investigated.

Many stretchable conductive composite fibers exhibit high elongation at break, but most of them do not have a large workable strain range towing to the low conductivity when used as strain sensors. In this paper, we fabricated a highly conductive silver nanowire (Ag NW)/multi-walled carbon nanotube (MWCNT)/thermoplastic polyurethane (TPU) fiber via a wet-spinning process to improve the workable strain range of composite fibers. TPU was used as a matrix material to introduce superior stretchability. MWCNTs act as sensing elements and Ag NWs were used to increase conductivity. We investigated the effect of Ag NW content on the mechanical, electrical, and strain-sensing performance of the fiber-type strain sensors. The optimal content of Ag NWs extended the workable strain range as higher as 254% with an electrical conductivity of 0.803 S/cm. A weight-to-strain cloth sensor was assembled by writing Ag NW/MWCNT/TPU fibers in the coagulation solution. Furthermore, such composite fiber can be free-written into any designed pattern, which can be used to prepare fiber-based devices.

Uniform carbon nano-fiber (CNF) films have been deposited onto carbon fabrics by sonication-assisted Electrophoretic Deposition (EPD). To examine the effect of sonication, the distributions of voltage and pH values in the deposition bath were measured during EPD process. The degree of uniformity of CNF deposition was analyzed from the morphology of the deposited CNFs by scanning electron microscopy. The neutralization of negative charged CNFs by hydrogen ions, which were generated by electrolysis of water at the anode (carbon fabric), is essential for the adsorption of CNFs onto carbon fabrics. In addition, sonication increases the movement of ions in the suspension and accelerates the neutralization of CNFs at the anode. Moreover, sonication overcomes the aggregation and settlement of CNFs at the bottom of the deposition bath caused by gravity. The bubbles, which were generated by electrolysis of water, in the vicinity of the carbon fabrics were removed by sonication, resulting in the improvement of CNFs deposition. Based upon the results of voltage and pH values distributions during the EPD and analysis of morphologies of CNF films, a mechanism of sonication-assisted EPD has been proposed.