Abstract
A temperature limitation mechanism for solar evacuated tubular collectors (ETCs) has been developed which is centered around the reversible adsorption of benzene by the spectrally selective cermet film in the collector vacuum space. Benzene desorption behavior of microporous amorphous hydrogenated carbon films (the adsorbing component of the cermet) has been investigated using thermal desorption spectroscopy (TDS). Desorption spectra show two peaks which vary in intensity and line shape with film thickness and coverage. Gas adsorption studies undertaken using a Kelvin probe are presented which show changes in contact potential difference (CPD) of a-C:H films in response to a variety of adsorbates. Strong surface adsorption of oxygen and nitrogen species was detected. A comparison TDS and CPD results has shown that benzene is adsorbed exclusively in the pore volume.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
