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Q: I would like to know where the O1s binding energy for an oxycarbide bond O-Mo-C would appear. Usually when people report binding energies for oxycarbides they never talk about the O1s region. Could you guys give me some pointers ?. Thanks in advance.Hector, Central University of Venezuela
Answer: Dear Hector, Thanks for getting in touch with us. The position of the first peak O1s is always in a narrow window of around 531eV. The first peak derived from oxygen for 1s photoelectron in oxygen for oxycarbide bond should have binding energy of 533eV. You need to collect XPS data and determine the position of O1s peak. Binding energies are reported in literature for O1s peak. That region is well known.
I hope this helps, if you have further questions, please send us an email to [email protected] with your contact details and we would be happy to assist you. Alternatively, please contact us at our main office, +44 208 795 9400.Dr Dan Burnett, Surface Measurement Systems Ltd.
Q: Hi, I’m new to use the DVS and I have to use it even though there is no previous user available now in my college. I used the instrument but the problem that I don’t have any change in the mass. The relative humidity is changing and affect the material which can be monitored by the change of its colour but the mass still as the value of the reading of auto mass. Do I have problem with calibration or what?John, Imperial College
Answer: Dear John, Thanks for getting in touch with us. To check if there is problem to your calibration, please send us an email to [email protected] with your contact details and our service team would be happy to assist you. Alternatively, please contact us at +44 208 795 9400.Dr Dan Burnett, Surface Measurement Systems Ltd.
Q: How to measure surface energy?John, Taiwan
Answer: Surface energy is an important property in numerous industrial application and processes. It shows a strong dependency on various macroscopic properties and relates to many crucial interfacial phenomena, i.e. adhesion and wetting behaviors. Surface energy is typically divided into two main components: dispersive (London, van der Walls, Liftshitz interactions) and acid-base (polar, electron donor-acceptor interactions). Inverse Gas Chromatography (IGC) measures surface energy values by measuring the retention volumes for a series of alkanes and polar probe molecules to determine the dispersive surface energy component and the acid-base surface energy component, respectively. For more details on measuring surface energy and surface energy heterogeneity by IGC, please refer to iGC-SEA Application Notes 202, 224, and 226.Dr Dan Burnett, Surface Measurement Systems Ltd.
Q: What are the parameters that can be measured to determine the surface energy of small particles?Abdulrhman, Macanah
Answer: The total surface energy is typically divided into two main components: dispersive (non-polar) and acid-base (polar). The dispersive surface energy is determined by measuring the net retention volume for a series of alkane elutants (i.e. heptane, octane, nonane, and decane). Then, either the Shultz or Dorris/Gray method is used to calculate the dispersive surface energy. For the acid-base surface energy, first the specific free energies of desorption are determined by measuring the retention volume of monopolar acid (i.e. dichloromethane or chloroform) or monopolar base (i.e. toluene or ethyl acetate) probe molecules. Then, the specific free energy values of these polar probes are used in conjunction with the Good, van-Oss, and Chaudury approach to determine the acid-base component of the surface energy. For more information on measuring surface energies and surface energy heterogeneity profiles, please see iGC-SEA Application Notes 202, 221, and 224.Dr Dan Burnett, Surface Measurement Systems Ltd.