Abstract: An optical sensor for detection of gases such as nitrogen oxides includes a thin film of an active material comprising a highly polarisable organic material deposited by the Langmuir-Blodgett technique or otherwise on a substrate and interrogated optically, to detect changes in at least one optical property such as reflectance or complex refractive index. Preferred materials include a specific polysiloxane and low-molecular-mass compounds (FIGS 1 to 5b), having specific electron donating and/or accepting groups, including azobenzenes. The optical change may include a visible colour change.

Abstract: A protective covering material for use such as shingles and siding is primarily composed of a formulation of polyvinyl chloride resin and plasticizer which is mixed with vermiculite is disclosed. The plasticized polyvinyl chloride formulation is approximately composed of 81.5 parts of polyvinyl chloride resin suspension polymer, 23.5 parts plasticizer Di-2-ethylhexyl phthalate, 2.75 parts epoxidized soybean oil, 1.25 parts barium calcium and 1 part copper sulphate. The formula and ingredients and vermiculite are mixed and subsequently heated until they reach a liquid state, whereupon as a mixture they are extruded into sheet-like form and chill-rolled. After the sheet of the combined formulation and vermiculite reach the proper temperature, the sheet is cut into the desired configuration for roofing shingles or other protective covering materials.