Investigation of the effect of laponite and crosslinkers on thermal, mechanical, swelling and conductive properties of the phtagel composite films


EKİCİ S. , GUNGOR G.

SMART MATERIALS AND STRUCTURES, cilt.26, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 26 Konu: 3
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1088/1361-665x/aa5f05
  • Dergi Adı: SMART MATERIALS AND STRUCTURES

Özet

Phytagel (PHG)-laponite (L) composites were prepared in the form of films by using PHG known to be biocompatible with the body, L clay which has electrical conductivity, and weak and strong crosslinkers, i.e., 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (E) and Cu2+, respectively. Composites were obtained by using laponite in two different ratios and only one concentration of Cu2+. Bare PHG and PHG films crosslinked with E were also prepared simultaneously and characterization of all the films are presented comparatively. Cu2+ ions are more effective crosslinkers than E molecules for PHG chains and increased the mechanical strength of composites as revealed in swelling studies and differential scanning calorimetry analysis. It was determined that laponite and Cu2+ ions increased the conductivity of PHG hydrogel and conductivity decreased when the amount of laponite is increased. Wet film samples had conductivity between 0.95 x 10(-8) and 5.94 x 10(-8) S cm(-1) values, while dry films were not conductive. Wet PHG, PHG-E, PHG-E-L1, and PHG-E-L2 films showed bending deformation towards the anode under electric field of 25 V in magnitude, while wet PHG-Cu-L2 films tended to bend towards the cathode side. It was concluded that these composites are intelligent hydrogel composites which can respond to stimuli such as environmental pH and electric field changes and can be considered for use in studies involving low electrical conductivity.