Most polymeric thermoset materials change (cure) slowly as they lie in storage; a prime example of this is composite prepreg materials. These changes are generally vitrification, and are not readily observable using some of the standard curemonitoring methods, such as DSC and FTIR, which sense mainl
Study of electrical properties of polymeric materials using electrochemical impedance spectroscopy
✍ Scribed by Rahul Sharma; Cortney Henderson; G. W. Warren; S. L. Burkett
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 156 KB
- Volume
- 68
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
✦ Synopsis
Electrochemical impedance spectroscopy (EIS) has been used to determine the water absorption characteristics of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyaromatic amide (Aramid), and amine-quinone polyurethane (AQ) free-standing polymer films. A method for calculating percent moisture uptake is presented based on capacitance measurements via EIS, which requires initial or ''dry'' capacitance values, C 0 . Three different methods for obtaining C 0 values were described and employed, but the most reliable values were obtained via EIS measurement using Hg contacts. C 0 values obtained by this method resulted in calculated water uptake values nearly identical to those obtained by measured weight gain. Lower capacitance values were observed for films immersed in distilled water compared to 0.1M NaCl, which indicates that water uptake is greater in NaCl than in pure water. The four polymers examined in this study can be listed in order of decreasing resistance to moisture absorption as AQ ú PET ú PEN ú Aramid.
📜 SIMILAR VOLUMES
## Abstract The influence of different restorative materials on in vitro dielectric properties of sound dentine was investigated. The studied samples were three‐layer materials consisting of successive disks of dentine and silver amalgam or nanohybrid composite resin. Before being tested, the sampl
## Abstract Actinomycin D or proflavine which are known to intercalate within the helix of double‐stranded DNA (dsDNA) are used as label‐free control to unequivocally prove complementary DNA hybridization by means of electrochemical impedance spectroscopy (EIS). Based on a carefully designed interf