Factors influencing degree substitution

The effect of the degree of substitution (DS) of CmDx samples on the pKjpp versus a plots are shown in Fig. 7. The pK p values at a specified a ue increase with the DS value of the CmDx sample, indicating that the linear charge density of the polyion is the predominant factor influencing the shape of the curve. The linear charge separation of the... 

Substitution of fluorine for hydrogen in an organic compound has a profound influence on the compound s chemical and physical properties. Several factors that are characteristic of fluorine and that underHe the observed effects are the large electronegativity of fluorine, its small size, the low degree of polarizabiHty of the carbon—fluorine bond and the weak intermolecular forces. These effects are illustrated by the comparisons of properties of fluorocarbons to chlorocarbons and hydrocarbons in Tables 1 and 2. 

It has been found that the influence of the membrane composition on the ISE selectivity is mainly governed by substitution degree of the nitrogen atom, but virtually does not depend upon the length of hydrocarbon substituents. The key factor in the selectivity of DBP-plasticized membranes with both kinds of ion-exchangers and of the o-NPOE-TNOBS-membrane is the ionic... 

The cellulase complex diffuses through the pore system to the microfibrils, attacks the cellulose chains and hydrolyses each chain to the end. The diflerences in the efficacy of cellulases on various fibres are dependent on number of factors such as the amounts of non-cellulosic wood pulp-derived matter, the degree ol polymerisation, the type and degree of crystallinity, and the type and number of chemical substitutions to the cellulose [27-30]. Key features for the cellulose substrate are crystallinity, accessible surface area and pore dimensions [31 ]. Variation of any of these factors, e.g., structural changes of cellulose substrate by pre-treatments, will influence the course of the entire degradation process [32, 33]. 

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