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This report summarizes GEO-CENTERS' programs in support of the Naval Research Laboratory's Surface Chemistry Branch of the Chemistry Division. These programs deal with the properties and chemistry on/at/near surfaces and interfaces. Of particular interest to the Navy are the advances and studies summarized as follows: Friction/Wear Testing & Surface Analysis: Examined & studied were the effects caused by chemistry & wear debris on the friction/wear of ion-implanted metals and ceramics, & the friction/wear of solid lubricating films. Air Purification: Emphasis centered on predicting the breakthrough behavior of high humidity air streams on activated carbon & the effect of relative humidity on the breakthrough of chemical challenges on impregnated carbon. Keywords: Surface analysis, Surface modification, Tribological characterization, Air purification, Chemical microsensors, Detection, Interface modification & analysis.

Modified ceramic and metal surfaces demonstrated significant improvements in tribological characteristics such as friction and wear resistance. In addition to the characterization and analysis of these materials, a large materials database was compiled. This information will assist in identifying important factors affecting stress propagation and tribological performance, and will aid in the development of models. In chemical microsensors, both SAWs and optical waveguides were evaluated with respect sensitivity, selectivity, and reproducibility. Application of these sensors for the detection of specific vapors was demonstrated. A model based on solubility interaction effectively predicts SAW coating behavior. In the area of decontamination, various charcoal substrates were evaluated, and models were developed to predict adsorbent behavior and performance. Keywords: Surface analysis, Surface modification and tribological characterization, Chemical microsensors, Air purification and detection., See also Volume 2, AD-A208 881.

Modified ceramic and metal surfaces demonstrated significant improvements in tribological characteristics such as friction and wear resistance. In addition to the characterization and analysis of these materials, a large materials database was compiled. This information will assist in identifying important factors affecting stress propagation and tribological performance, and will aid in the development of models. Keywords: Surface analysis, Surface modification and tribological characterization, Chemical microsensors, Air Purification and Detection., See also Volume 3, AD-A208 882.

Modified ceramic and metal surfaces demonstrated significant improvements in tribological characteristics such as friction and wear resistance. In addition to the characterization and analysis of these materials, a large important factors affecting stress propagation and tribological performance, and will aid in the development of models. Surface analysis, Surface modification and tribological characterization, Chemical microsensors, Air purification and detection., See also Volume 1, AD-A208 880.

A sensitive, inexpensive chemical microsensor is described that is capable of meeting performance requirements for DoD applications. Experimentally obtained frequency shifts for known mass loading compare favorably with theoretically predicted mass sensitivities for the 31, 52 and 112 MHz surface acoustic wave (SAW) devices. The 300 MHz SAW device exhibits a frequency stability of better than 1 part in 10 to the 7th power, as well as good temperature and pressure stability under ambient conditions. Response times were generally less than 10 sec. When coated with a fluorepoxy pre-polymer this device exhibited a calculated detection limit of 0.04 mg/cu m for DMMP.

An optical waveguide humidity detector is described that is reliable and inexpensive. It utilizes a cobalt chloride/poly(vinyl pyrrolidone) film on the surface of a thin walled glass capillary waveguide, and monitors the absorption change at 660 nm as the waveguide is exposed to H2O(g). The humidity response is an S-shaped curve with the inflection point between 65% and 80% RH; location of inflection point is correlated with CoCl2 and PVP concentration in the film. The effects of reagent concentration and film thickness on detector response are described. Keywords include: Capillary waveguide; Optical waveguide; Chloride/polyvinyl pyrorolidone, and Humidity detector.