摘要
Thermal analysis is essential for the characterization of polymers and drugs.However,the currently established methods require a large amount of sample.Here,we present pyrolytic carbon resonators as promising tools for micromechanical thermal analysis(MTA)of nanograms of polymers.Doubly clamped pre-stressed beams with a resonance frequency of 233±4 kHz and a quality factor(Q factor)of 800±200 were fabricated.Optimization of the electrical conductivity of the pyrolytic carbon allowed us to explore resistive heating for integrated temperature control.MTA was achieved by monitoring the resonance frequency and quality factor of the carbon resonators with and without a deposited sample as a function of temperature.To prove the potential of pyrolytic carbon resonators as thermal analysis tools,the glass transition temperature(T_(g))of semicrystalline poly(L-lactic acid)(PLLA)and the melting temperature(T_(m))of poly(caprolactone)(PCL)were determined.The results show that the T_(g) of PLLA and T_(m) of PCL are 61.0±0.8℃ and 60.0±1.0℃,respectively,which are in excellent agreement with the values measured by differential scanning calorimetry(DSC).
基金
The research is funded by the Danish National Research Foundation(DNRF122)
Villum Fonden(Grant No.9301)Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics(IDUN)
This work was performed in part at cleanroom facilities of DTU Nanolab,the National Center for Microfabrication and Nanofabrication at the Technical University of Denmark.
