Dielectric relaxation and Schottky conduction of IR laser irradiated Makrofol‐DE polycarbonate

Abstract

The effect of IR laser pulses on the dielectric properties, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and I-V characteristics of Makrofol-DE 1-1 CC polycarbonate has been investigated in the temperature and frequency ranges of 300-375K and 10 kHz-4 MHz, respectively. IR laser fluencies are set from 0.47 to 7.07 J/cm 2 . Three relaxation processes namely, a, b, and c have been obtained. The first process is due to the micro Brownian motion of the segmental parts of the main chain. The second process was assigned to the local motion of the dipoles within the crystalline phases of the sample. The third one was attributed to the crank shaft motion along the main chains of the Makrofol.X-ray diffraction and FTIR spectroscopy have revealed that the irradiation of Makrofol at the fluence range 0.94-7.07 J/cm 2 causes crosslinking formation inside the sample. Reduction in crystallinity of Makrofol at higher IR laser doses is due to the crosslinking formation taking place within polymer matrix. At higher voltage, the conduction mechanism of Makrofol-DE was identified as Shottky type. The attained results suggested strongly the applicability of Makrofol-DE in IR laser pulses dosimetry.

Direct laser writing of hydrophobic and hydrophilic valves in the same material applied to centrifugal microfluidics

“…[7][8][9][10] However, these characteristics carry some challenges when dealing with microuidics, where many times it is necessary to ne tune its properties for better uidic control. Several studies have tried to tune the PC's dielectric properties, 11 create surface modications (and wettability) 7 on devices, study the effect of chemical modication using laser ablation 12 and even ways to construct micropatterning 13 on surfaces. These current strategies to modify bare polymer surfaces mainly include chemical 14 and plasma 15 treatments, but direct laser surface modication is emerging as a more exible technique due to its ability to perform surface patterning at high precision.…”