Branching saturated cores

A review of WGC data for 38 oil samples (from this study and an archive of older data) was done to search for indications of biodegradation. Generally, analyses of whole oils and saturate hydrocarbon GCs in samples from heavily tar-stained core extracts as well as the better producing zones showed none of the usual signs of microbial biodegradation i.e. no obvious depletions in n-alkanes relative to branched and cyclic hydrocarbons (Fig. 9). 

Fig. 6 a-c. Biomarkers in a Hickman s Harbour core, a High molecular weight/low molecular weight n-alkanes, b phenolic/saturated+branched fatty acid ratio determined by TMAH thermo chemolysis,c 3,4-dimethoxybenzoic acid methyl ester (DMBA). Pb dates dates were obtained for the top 6 cm of the core. (After [92,106])... 

Z = monomer-shell-saturation level, = core (cystamine) multiplicity, A/t, = branch-cell (BC) multiplicity, G = generation. 

In the case of dendron/dendrimer syntheses, one may view those processes leading to those structures as simply sequentially staged (generations), quantized polymerization events. Of course, these events involve the polymerization of AB2 monomer units around a core to produce arrays of covalently bonded branch cells that may amplify up to the shell saturation limit as a function of generation. 

More quantitatively, we plot the normalized concentration (Cpy,s/Cpy,w) of solubilized pyrene against polymer concentration in Fig. 5.33a, where Cpy,s and Cpy,w represent the measured pyrene concentration in micellar solution and the saturated concentration in pure water, respectively. As shown in Fig. 5.33a, Cpys/Cpy, linearly increases with polymer concentration for all HB-(PAA) -g-(PS) +i copolymers with different n values. Moreover (Cpy,s/Cpy,w) =i > (Cpy,s/Cpy,w) =io > (Cpy,s/Cpy,w)n=47, indicating the solubilization efficiency of HB-(PAA) -g-(PS) +i copolymers decreases with the size or branching degree of hyperbranched PAA core for a given polymer concentration. As we know, pyrene molecules mainly... 

---