Now showing 1 - 2 of 2
  • Publication
    Remote and precise control over morphology and motion of organic crystals by using magnetic field
    ( 2022) ;
    Yang, Xuesong
    ;
    Lan, Linfeng
    ;
    Liu, Xiaokong
    ;
    Naumov, Panče
    ;
    Zhang, Hongyu
    Elastic organic crystals are the materials foundation of future lightweight flexible electronic, optical and sensing devices, yet precise control over their deformation has not been accomplished. Here, we report a general non-destructive approach to remote bending of organic crystals. Flexible organic crystals are coupled to magnetic nanoparticles to prepare hybrid actuating elements whose shape can be arbitrarily and precisely controlled simply by using magnetic field. The crystals are mechanically and chemically robust, and can be flexed precisely to a predetermined curvature with complete retention of their macroscopic integrity at least several thousand times in contactless mode, in air or in a liquid medium. These crystals are used as optical waveguides whose light output can be precisely and remotely controlled by using a permanent magnet. This approach expands the range of applications of flexible organic crystals beyond the known limitations with other methods for control of their shape, and opens prospects for their direct implementation in flexible devices such as sensors, emitters, and other (opto)electronics.
    Scopus© Citations 2  10  1
  • Publication
    Shrinkage, hydration, and strength development of limestone calcined clay cement (LC3) with different sulfation levels
    ( 2022) ;
    Rotana Hay
    ;
    Kemal Celik
    This study investigated autogenous shrinkage of limestone calcined clay cement (LC3)-based mixes with various sulfation levels of hemihydrate. Physicochemical evolution and strength development were also monitored. Superior mechanical performance of the mixes was achieved at an optimal sulfation level, although the shrinkage was reduced with the sulfate content. Calorimetry data showed the hemihydrate delayed and broadened the second aluminate peak. Both gypsum and ettringite formed early during hydration, and carboaluminates were observed after 3 days of curing. Ettringite in the LC3 mixes was of smaller sizes in comparison to that in the ordinary Portland cement (OPC) mixes, attributable to the pore refinement in the LC3 matrices. The content of portlandite (Ca(OH)2) was reduced with the curing time due to pozzolanic reactions. The findings demonstrated a coupling effect of both the chemical and microstructural change on the observed autogenous shrinkage and the consequent performance of LC3-based concrete composites.
      39  4Scopus© Citations 5