The properties of silica surfaces are reviewed. The esterification of silica (Porasil C) with 3-hydroxypropionitrile is described. The surface site requirement of the organic molecule is 25.4 Å2. Such brush type stationary phases do not “bleed” below their decomposition temperature. The h vs ū curves have an unusually broad minimum in the velocity range of ū = 2–6 cm/sec. The h values are small (0.35–0.4 mm at ū = 6.6 cm/sec) and are independent of: 1) the nature of sample, 2) the temperature, 3) the capacity ratios (k′ = 1–140), 4) the sample size (10−8−10−3 g per compound). Optimal analytical conditions are discussed. Up to 30 effective plates per second are generated. Capacity ratios and relative retentions are tabulated.