A Parametric Study and Characterization of Porous, Non-Permeable, and Conductive PEGDA-HEMA Hydrogels

Author(s):  
Christine Chan ◽  
Shannon Chang ◽  
Hani E. Naguib

This study involved the development and characterization of novel porous, non-permeable, and conductive hydrogels. The hydrogels were fabricated with HEMA and crosslinked with PEGDA through a complete parametric study of the synthesis parameters which included water content and crosslinking content. The hydrogels were fabricated using UV photopolymerization and in situ polymerization of PPy, and characterization was conducted with respect to their physical, thermal, mechanical, and electrical properties. The physical properties were analyzed with respect to their swelling ratio and equilibrium water content. The thermal properties were analyzed based on the decomposition temperature and residue weight. The mechanical properties examined the elastic modulus of the hydrogels, and the electrical properties investigated the conductivity of the hydrogels. The relationships observed between the processing, structure, and resulting properties provide the basis for further development and application of these porous, non-permeable, and conductive hydrogels.

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1078 ◽  
Author(s):  
Ji Min ◽  
Madhumita Patel ◽  
Won-Gun Koh

In the field of tissue engineering, conductive hydrogels have been the most effective biomaterials to mimic the biological and electrical properties of tissues in the human body. The main advantages of conductive hydrogels include not only their physical properties but also their adequate electrical properties, which provide electrical signals to cells efficiently. However, when introducing a conductive material into a non-conductive hydrogel, a conflicting relationship between the electrical and mechanical properties may develop. This review examines the strengths and weaknesses of the generation of conductive hydrogels using various conductive materials such as metal nanoparticles, carbons, and conductive polymers. The fabrication method of blending, coating, and in situ polymerization is also added. Furthermore, the applications of conductive hydrogel in cardiac tissue engineering, nerve tissue engineering, and bone tissue engineering and skin regeneration are discussed in detail.


Author(s):  
Christine Chan ◽  
Weijia Zhang ◽  
Hani E. Naguib

Novel polypyrrole-polylactide blends were fabricated and characterized using compression molding, salt leaching, and in situ polymerization. Open-porous polylactide samples were fabricated using compression molding and salt leaching techniques with varying salt-to-polymer mass ratios of 3:1, 6:1, and 9:1. The samples then underwent in situ polymerization of pyrrole and iron (III) chloride to obtain a uniform coating of polypyrrole. Characterization of these novel composites comprised of their physical, mechanical, and electrical properties. With increasing salt-to-polymer mass ratio, it was found that the relative density decreased, the open porosity increased while pore size and pore density generally remained independent. The polypyrrole coating did not have a significant effect on the structure of the pore network. Microscopic polypyrrole nodules were observed to be uniformly coated on the surface and sub-surface of the composites. The compressive modulus decreased with increasing salt-to-polymer mass ratios. In addition, the modulus of the coated 3:1 salt-to-polymer mass ratio sample was twice the value obtained for the uncoated sample while the modulus values for the 6:1 and 9:1 samples did not significantly change. The conductivity increased as the salt-to-polymer mass ratio increased. The relationships observed between the structure and resulting properties provided the basis for future development and characterization of these novel porous composites.


Polymer ◽  
2011 ◽  
Vol 52 (23) ◽  
pp. 5237-5242 ◽  
Author(s):  
Nguyen Dang Luong ◽  
Ulla Hippi ◽  
Juuso T. Korhonen ◽  
Antti J. Soininen ◽  
Janne Ruokolainen ◽  
...  

2009 ◽  
Vol 1240 ◽  
Author(s):  
Ji-Ye Kang ◽  
Su-Mi Eo ◽  
Loon-Seng Tan ◽  
Jong-Beom Baek

AbstractSingle-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube (MWCNT) were functionalized with 3,4-diaminobenzoic acid via “direct” Friedel-Crafts acylation reaction in PPA/P2O5 to afford ortho-diamino-functionalized SWCNT (DIF-SWCNT) and MWCNT (DIF-MWCNT). The resultant DIF-SWCNT and DIF-MWCNT showed improved solubility and dispersibility. To improve interfacial adhesion between CNT and polymer matrix, the grafting of ABPBI onto the surface of DIF-SWCNT (10 wt%) or DIF-MWCNT (10 wt%) was conducted by simple in-situ polymerization of AB monomer, 3,4-diaminobenzoic acid dihydrochloride, in PPA. The resultant ABPBI-g-MWCNT and ABPBI-g-SWCNT showed improved the mechanical and electrical properties.


1991 ◽  
Vol 6 (10) ◽  
pp. 2054-2058 ◽  
Author(s):  
B-S. Hong ◽  
T.O. Mason

Via in situ electrical property measurements (conductivity, Seebeck coefficient) over the temperature range 500–800 °C and oxygen partial pressure range 10−4-1 atm, the equilibrium transport properties and stability range of YBa2Cu4O8 were determined. YBa2Cu4O8 behaves like the intrinsically mixed-valent compound, magnetite (Fe3O4), with small variations in electrical properties with changes in oxygen partial pressure. The decomposition boundary to YBa2Cu3O6+y (or YBa2Cu3.5O7.5±z) and CuO occurs at log(po2, atm) = −1.24 × 104/T(K) + 11.01(773 ⋚ T(K) ⋚ 1073).


2010 ◽  
Vol 663-665 ◽  
pp. 542-545 ◽  
Author(s):  
Bing Jie Zhu ◽  
Xin Wei Wang ◽  
Mei Fang Zhu ◽  
Qing Hong Zhang ◽  
Yao Gang Li ◽  
...  

The PANI/ITO conducting nanocomposites have been synthesized by in-situ polymerization. The obtained nanocomposites were characterized by X-ray diffraction pattern, scanning electron microscopy and Fourier transform infrared. Electrical conductivity measurements on the samples pressed into pellets showed that the maximum conductivity attained 2.0 ± 0.05 S/cm for PANI/ITO nanocomposites, at ITO doping concentration of 10 wt%. The results of the present work may provide a simple, rapid and efficient approach for preparing PANI/ITO nanocomposites.


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