Filters

2019 - 201912020 - 20221

More filters

2020 - 20232
Reset filters

Settings

Author: Jia, Guobin × Publisher: Basel : MDPI ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Copper Iodide on Spacer Fabrics as Textile Thermoelectric Device for Energy Generation
    (Basel : MDPI, 2022) Schmidl, Gabriele; Jia, Guobin; Gawlik, Annett; Lorenz, Philipp; Zieger, Gabriel; Dellith, Jan; Diegel, Marco; Plentz, Jonathan
    The integration of electronic functionalities into textiles for use as wearable sensors, energy harvesters, or coolers has become increasingly important in recent years. A special focus is on efficient thermoelectric materials. Copper iodide as a p-type thermoelectrically active, nontoxic material is attractive for energy harvesting and energy generation because of its transparency and possible high-power factor. The deposition of CuI on polyester spacer fabrics by wet chemical processes represents a great potential for use in textile industry for example as flexible thermoelectric energy generators in the leisure or industrial sector as well as in medical technologies. The deposited material on polyester yarn is investigated by electron microscopy, x-ray diffraction and by thermoelectric measurements. The Seebeck coefficient was observed between 112 and 153 µV/K in a temperature range between 30 °C and 90 °C. It is demonstrated that the maximum output power reached 99 nW at temperature difference of 65.5 K with respect to room temperature for a single textile element. However, several elements can be connected in series and the output power can be linear upscaled. Thus, CuI coated on 3D spacer fabrics can be attractive to fabricate thermoelectric devices especially in the lower temperature range for textile medical or leisure applications.
  • Thumbnail Image
    Item
    Large area graphene deposition on hydrophobic surfaces, flexible textiles, glass fibers, 3D structures, and adhesion of graphene layer
    (Basel : MDPI, 2019) Jia, Guobin; Plentz, Jonathan; Dellith, Jan; Dellith, Andrea; Wahyuono, Ruri Agung; Andrä, Gudrun
    Graphene and its derivatives have many superior electrical, thermal, mechanical, chemical, and structural properties, and promise for many applications. One of the issues for scalable applications is the lack of a simple, reliable method that allows the deposit of a well-ordered monolayer using low-cost graphene flakes onto target substrates with different surface properties. Another issue is the adhesion of the deposited graphene thin film, which has not been well investigated yet. Following our former finding of a double self-assembly (DSA) process for efficient deposition of a monolayer of graphene flakes (MGFs), in this work we demonstrate that the DSA process can be applied even on very challenging samples including highly hydrophobic polytetrafluoroethylene (PTFE), flexible textiles, complex 3D objects, and thin glass fibers. Additionally, we tested adhesion of the graphene flakes on the flat glass substrate by scotch tape peel test of the MGFs. The results show that the graphene flakes adhere quite well on the flat glass substrate and most of the graphene flakes stay on the glass. These findings may trigger many large-scale applications of low-cost graphene feedstocks and other 2D materials.