<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Baltrusaitis, Jonas</style></author><author><style face="normal" font="default" size="100%">Usher, Courtney R.</style></author><author><style face="normal" font="default" size="100%">Grassian, Vicki H.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Reactions of sulfur dioxide on calcium carbonate single crystal and particle surfaces at the adsorbed water carbonate interface.</style></title><secondary-title><style face="normal" font="default" size="100%">Phys. Chem. Chem. Phys.Physical Chemistry Chemical Physics</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">reaction sulfur dioxide calcium carbonate single crystal adsorbed water</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">Royal Society of Chemistry</style></publisher><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">3011 - 3024</style></pages><isbn><style face="normal" font="default" size="100%">1463-9076</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Sulfur dioxide reactions with calcium carbonate interfaces at 296 K in the presence and absence of adsorbed water result in the formation of adsorbed sulfite and sulfate.  The extent of reaction is significantly enhanced, approx. five- to ten-fold for particulate and single crystal CaCO3 (calcite), resp., in the presence of adsorbed water between 30 and 85% RH.  At. force microscopy following the reaction shows that adsorbed water facilitates surface reactivity by enhancing the mobility of surface ions, giving rise to the formation of nanometer sized product crystallites approx. 1 nm in height.  Simultaneous with the formation of these crystallites is pitting and etching of the underlying substrate, which occurs preferentially in the vicinity of monoat. surface steps.  In the absence of water, there is little pitting and no evidence for the formation of crystallites.  X-Ray photoelectron core and valence band spectra confirm the presence of two sulfur adsorbed species, SO2-3 and SO2-4, with nearly equal amts. of SO2-3 and SO2-4 in the absence of adsorbed water and approx. five times more SO2-3 relative to SO2-4 in the presence of adsorbed water.  From these data, it is proposed that the nanometer-sized crystallites are composed primarily of CaSO3. [on SciFinder(R)]</style></abstract><issue><style face="normal" font="default" size="100%">23</style></issue><notes><style face="normal" font="default" size="100%">CAPLUS AN 2007:608637(Journal)</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Usher, Courtney R.</style></author><author><style face="normal" font="default" size="100%">Baltrusaitis, Jonas</style></author><author><style face="normal" font="default" size="100%">Grassian, Vicki H.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Spatially Resolved Product Formation in the Reaction of Formic Acid with Calcium Carbonate (101̅4): The Role of Step Density and Adsorbed Water-Assisted Ion Mobility.</style></title><secondary-title><style face="normal" font="default" size="100%">Langmuir</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">step density ion mobility reaction formic acid calcium carbonate</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">American Chemical Society</style></publisher><volume><style face="normal" font="default" size="100%">23</style></volume><pages><style face="normal" font="default" size="100%">7039 - 7045</style></pages><isbn><style face="normal" font="default" size="100%">0743-7463</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The reaction of calcium carbonate (101̅4) single-crystal surfaces with formic acid (HCOOH) vapor was investigated using at. force microscopy (AFM) and XPS.  AFM images indicate the reaction produces rather well-defined crystallites, preferentially at step edges and at distinct angles to one another and mirroring the rhombohedral structure of the calcite surface, while exposing unreacted carbonate surface.  The size and surface d. of the crystallites depend upon substrate step d., exposure time, and relative humidity.  XPS data confirmed the crystallite compn. as the expected calcium formate product.  The AFM images show erosion and pit formation of the calcite surface in the vicinity of the product crystallites, clearly providing the spatially resolved characterization of the source of Ca ions.  AFM expts. exploring the effects of water vapor on the reacted surface show that the calcium formate crystallites are mobile under conditions of high relative humidity, combining to form larger crystallites and nanometer-sized crystals with an orthorhombohedral habit consistent with the α form, as confirmed by X-ray diffraction.  The implications for the reactions described here are discussed. [on SciFinder(R)]</style></abstract><issue><style face="normal" font="default" size="100%">13</style></issue><notes><style face="normal" font="default" size="100%">CAPLUS AN 2007:521222(Journal)</style></notes></record></records></xml>