Near infrared tunable diode laser (NE-TDL) spectroscopy is used to quantify HF gas produced during fire suppressant testing of halon alternatives. Results of comparisons with other techniques for measuring HF gas concentrations are discussed. Measurements of HF gas produced in laboratory and real-scale fire suppression testing are presented. The necessity for time-resolved measurements during t...

Low-energy ion-surface collisions of methyl cation at hydrocarbon and fluorocarbon self-assembled monolayer (SAM) surfaces produce extensive neutralization of CH3+. These experimental observations are reported together with the results obtained for ion-surface collisions with the molecular ions of benzene, styrene, 3-fluorobenzonitrile, 1,3,5-triazine, and ammonia on the same surfaces. For comp...

Triphilic star-polyphiles are short-chain oligomeric molecules with a radial arrangement of hydrophilic, hydrocarbon and fluorocarbon chains linked to a common centre. They form a number of liquid crystalline structures when mixed with water. In this contribution we focus on a hexagonal liquid crystalline mesophase found in star-polyphiles as compared to the corresponding double-chain surfactan...

We have undertaken atomistic molecular simulations to systematically determine the structural contributions to the hydrophobicity of fluorinated solutes and surfaces compared to the corresponding hydrocarbon, yielding a unified explanation for these phenomena. We have transformed a short chain alkane, n-octane, to n-perfluorooctane in stages. The free-energy changes and the entropic components ...

We report the preparation of loosely packed hydroxyl-terminated self-assembled monolayers (SAMs) on gold by the adsorption of bis(11,11'-dithioundecyl)perfluoroheptanoate and base-mediated cleavage of the fluorocarbon terminal group. As shown through complementary characterization methods, the partially fluorinated SAM exhibits a structure in which the outer surface contains mostly -CF(3) group...

A series of hydrocarbon and fluorocarbon carbohydrate surfactants with different headgroups (i.e., gluco-, galacto- and maltopyranoside) and (fluorinated) alkyl tails (i.e., C7 and C14 to C19) was synthesized to investigate trends in their cytotoxicity and haemolytic activity, and how surfactant-lipid interactions of selected surfactants contribute to these two measures of biocompatibility. All...

Adsorption heat transformation is one of the most energy-efficient technologies, which relies much on the type and performance of the adsorbent–adsorbate pair. Here, we report adsorption behaviors of a typical fluorocarbon R22 (CHClF2) in a new series of isoreticular porous coordination polymers [Zn4O(bpz)2(ldc)], in which the typical Zn4O clusters are connected by hydrophobic 3,30,5,50-tetrame...

The influence of different environmental factors on methane oxidation and degradation of hydrochlorofluorocarbons (HCFCs) was investigated in microcosms containing soil sampled at Skellingsted Landfill, Denmark. The soil showed a high capacity for methane oxidation resulting in a maximum oxidation rate of 104 microg CH4 g(-1) h(-1) and a low affinity of methane with a half-saturation constant o...

Temperature-dependent phase-vanishing processes between perfluorohexane (FC-72) and n-heptane (C7H16, volume ratio of 1:1 and phase-vanishing temperature>41 degrees C), were studied in a glass microchannel-microheater chip under solution-flow conditions. Without applying a voltage to the heater at 21 degrees C, the two liquids in the microchannel were separated into two streams at a solution fl...