Surface Characterization

Abstract

Reviews of surface characterization have appeared in Analytical Chemistry every two years since 1977 (1-11). The field continues to grow and diversify with new surface analysis techniques as well as new applications. This review is similar to the last one in this series, being written by multiple authors with different specialties in an attempt to highlight advances in each of these areas. This review begins with literature from January 1997 and ends with literature from approximately October, 1998.

Characterising chemical functionality on carbon surfaces

“…Of the latter, X-ray photoelectron spectroscopy (XPS) [42][43][44][45][46][47] and vibrational spectroscopic methods 48,49 (infra-red and Raman spectroscopy) are the most common. The interested reader is directed to a review of different surface characterisation techniques used on carbon surfaces written by McGuire et al 50 Vibrational spectroscopy is capable of providing qualitative data indicating the presence or absence of certain kinds of surface oxo groups by, for example, identifying an O-H stretch and a C]O stretch associated with the presence of carboxyl groups. However, quantitative analysis of the relevant amounts of each type of functional group is more difficult, particularly where, for example, O-H stretches from different functional groups such as hydroxyl, phenol or carboxyl groups overlap to any extent.…”

Primostrato Solid-State NMR Enhanced by Dynamic Nuclear Polarization: Pentacoordinated Al3+ Ions Are Only Located at the Surface of Hydrated γ-Alumina

“…For the case of γ-alumina impregnated with bTbK in TBE, there is also an influence on the T 2 ′( 27 Al) of the surface 27 Al nuclei coming from a direct interaction with the radicals. Unlike for surface 27 Al nuclei studied under decoupling, intrinsic surface 1 H nuclei (in hydroxyls or physisorbed/coordinated water) will be coupled to other 1 H nuclei from the added solvent. Therefore, the addition of solvent will have an effect on measurements that involve protons, as has been shown for T B 1 H and T D CP .…”

“…1 As always, each technique will exhibit specific benefits but will also suffer from specific limitations (e.g., limit of detection, spatial and time resolution, penetration depth, restrictions on sample type, cost, and availability). So far, solidstate nuclear magnetic resonance (SSNMR) spectroscopy has been largely overlooked by the surface characterization community.…”

“…A variety of techniques are available for the characterization of surfaces (ion beam analysis, electron spectroscopy, proximal probes, X-ray techniques, optical techniques, scanning-tunneling microscopy, etc.). 1 As always, each technique will exhibit specific benefits but will also suffer from specific limitations (e.g., limit of detection, spatial and time resolution, penetration depth, restrictions on sample type, cost, and availability). So far, solidstate nuclear magnetic resonance (SSNMR) spectroscopy has been largely overlooked by the surface characterization community.…”

Low-cost apparatus for measuring undispersed particles in extruded plastic ribbon

“…While optical techniques provide the basis for a wide number of rapid and precise measurements, 6,7 they are by no means the only choice. 8,9 Although the polymer analyst is faced with the task of choosing from among dozens of potentially applicable techniques, fortunately his task is simplified somewhat because there often is not the need to identify the particles for chemical composition (as many of the more sophisticated optical techniques do), rather only to quantify the number of particles that manifest themselves on the surface of the plastic sheet. There are very few commercial instruments applicable, all having limitations stemming from the mobility of the device, to the opacity of the sheet, to the cost of implementation.…”