Swellable organically modified silica (SOMS) is a sol–gel derived material that spontaneously expands >2.5× upon contact with organic liquids, absorbing 7.8 mL/g. Adsorption of gas-phase volatile organic compounds by SOMS was measured to examine how the capability to swell affects capacity and rate of organic vapor absorption. Static adsorption capacities of SOMS for organic vapors at saturated vapor pressure ranged from 0.7 to 1.05 g/g, which was higher than values for other sorbents (powdered activated carbon, Amberlite XAD-4, Tenax TA, OptiPore, and organophilic zeolite). Rates of adsorption by SOMS were similar to those of XAD-4, a porous polymer with similar surface chemistry, and slower than that of activated carbon. Sequential coadsorption of multiple compounds by SOMS was measured, yielding enhanced adsorption capacity attributed to adsorption-induced pore expansion. The sequential adsorption of phenol and acetone vapor (p = p 0) led to a total capacity of 5.7 g/g. Adsorption of organic vapors was not selective and fully reversible in all cases. The hydrophobicity of SOMS strongly excludes water and water vapor. Fluorescence recovery after photobleaching was used to measure in-particle diffusion constants of fluorescein before and after adsorption for vapor and liquid.

Devices producing different colored smokes have been widely used by military and civilians for signaling, screening, and display. Attention has not yet been placed on the analysis of the combustion products from these devices which may be hazardous. Combustion products from these colored smokes containing organic dyes produced at the normal function temperature (approximately 400°C–600°C) of the compositions have been studied in our laboratory. The five dyes contained in the smoke compositions studied are: benzanthrone, dibenzo(a,h)pyrene‐7,14‐dione, 1,4‐di‐p‐toluidino‐anthraquinone, 1‐methylamino‐anthraquinone, and α‐xylene‐azo‐β‐naphthol. A modified EPA‐Method 5 sampling train containing Amberlite XAD‐2 as the absorbant was used to sample the organic vapors and particulates in the effluent. ánalytical methods used to separate, purify, and identify the products include TLC, HPLC, GC, GC‐MS, and NMR. Minimum destruction of the organic dyes is desired for a good smoke. Our preliminary investigations indicate that 90%–95% of the organic dye sublimes while the other 5%–10% is lost to combustion. The combustion products observed, to date, have been identified as polynuclear aromatic hydrocarbons (PAH's) and polynuclear organic materials (POM's) which are the result of thermal decomposition and thermal rearrangement of the parent dyes. At the temperature of functioning, no ring opening of the dyes has been observed.