Chemical heterogeneity investigation

The interaction of a simple fluid with a single chemically heterogeneous substrate has also been studied. Koch et al. consider a semiinfinite planar substrate with a sharp junction between weakly and strongly attractive portions and investigate the influence of this junction on the density profile of the fluid in front of the substrate [172-174]. Lenz and Lipowsky, on the other hand, are concerned with formation and morphology of micrometer droplets [175]. 

The investigation of structural dynamics of CP is particularly topical in connection with the establishment of correlation between local intramolecular mobility and the reactivity of chain fragments. It has been established that groups located in the most mobile parts of the polymer chain exhibit the greatest reactivity [48], The chemical heterogeneity in relationship to local mobility is particularly... 

In this paper, we report a study of the photocatalytic oxidation in the neat-liquid phase and at room temperature of various model hydrocarbons containing one or two C6 rings (cyclohexane, methyl- and dimethyl-cyclohexane, cyclohexene, decalin and tetralin) over TiC>2 to further investigate the possibilities of heterogeneous photocatalysis in the field of fine chemicals. Bibliographic investigations gave no references on the photocatalytic oxidation of the various hydrocarbons cited above, except for cyclohexane (refs 6 - 8) with which wa have initiated the study of liquid cycloalkanes (ref. 9). 

Schumacher, M., Christl, I., Scheinost, A. C., Jacobsen, C., and Kretzschmar, R. (2005). Chemical heterogeneity of organic soil colloids investigated by scanning transmission X-ray microscopy and C-ls NEXAFS microspectroscopy. Environ. Sci. Technol. 39, 9094-9100. 

Dow Chemical Company investigated homogeneous as well as heterogeneous Nd-amide-based catalysts with regard to their industrial applicability [321,322]. 

Strictly speaking, Balke s system combined SEC in the first dimension with a mixed mode separation in the second dimension. Since SEC separates with respect to hydrodynamic volume and not molar mass, the copolymers under investigation could not be quantified with respect to molar mass distribution (see discussion in Sect. 3). The effect of the SEC separation was simply to obtain fractions with narrower molar mass distribution as compared to the total sample. Considering this fact, it is clear that for chemically heterogeneous copolymers no quantitative data can be obtained from the first dimension. Only the second dimension, separating with respect to chemical composition, can provide quantitative information on the chemical composition distribution. Accordingly, a coupled information on both MMD and CCD was not available for this system. 

Investigations of Chemical Heterogeneity in Polydimethylsiloxanes using SFC, HPLC, and MALDI-MS... 

In a series of mostly theoretical model studies Marmur et al. - ) Investigated the role of the drop volume for smooth surfaces, containing oscillatory chemical heterogeneities. The idea, that many metastable states may exist for rough and heterogeneous surfaces, was pushed ahead by showing that the dependence of the... 

Two possible origins of the damage have been investigated localized high levels of load at the point of deformation and chemical heterogeneity at... 

We want to focus on the modification of substrate electrodes with metal particles of mesoscopic dimensions and their characterization with STM. For such chemically heterogeneous surfaces, the chemical information complementing the structural investigation is required. The different chemical compositions of the constituents, namely the substrate and the deposit, is often manifest in different characteristic mesoscopic structures of both. Tlius, although the chemical selectivity of STM is rather poor, this chemical information can often be concluded fiom the mesoscopic structure. 

Most nuclear forensic samples are physically and chemically heterogeneous, while the MS techniques discussed in preceding paragraphs pertain to analyses of homogeneous bulk samples. Complementary techniques involving in situ microscale isotope and trace-element analyses also play a pivotal role in nuclear forensic investigations. 

Without any doubt there are scientific questionings in peptide chemistry which can be answered by conventional methods and by the gel phase approach as well. It was demonstrated that most of the classic methodical arsenal in peptide chemistry can be successfully transferred to investigations utilizing polymeric phases, if the chemical heterogeneity of the macromolecular reaction points is taken in consideration with critical care. 

While there are molar mass sensitive detectors for the determination of the MMD of homopolymers, the applicability of these detectors for copolymers suffers from potential co-elution in SEC and (in case of Ught scattering) from the dependence of the dnidc of composition. In addition, these detectors do not provide any insight into the CCD. There are different methods established on how to investigate the chemical heterogeneity with SEC or with related techniques. 

---