Swelling ability

The resins can be divided into two groups having major structural differences gel and macroreticular . In the case of gel type resins if the beads are totally dry, then the polymeric matrix collapses and the polystyrene chains will be as close as atomic forces allow. Therefore, swelling ability of the reactants is a prerequisite for catalysis by gel resins. Gel resins are characterized by a divinyl benzene content that is generally below 12%. 

This type of solid was synthesized with complexes such as [HRh(CO) PPh2(CH2)3S= 3] and [ClRuH P(0)(CH2)3Si= 3] (which were tested as catalysts for the hydrogenation and hydroformylation of tolan), and [(dba)Pd P(0)(CH2)3Si= 2] (tested for copolymerization reactions). 8-91 The activity and the selectivity of these catalysts are in all cases solvent-dependent, a phenomenon explained by their swelling ability. The authors claim that no leaching is occurring. 

Comparison of polystyrene-supported phosphonium ion catalysts 1 in the reaction of 1-bromooctane with iodide ion showed a 4.5 % CL catalyst to be only half as active as a 2% CL catalyst74 . Use of decane, toluene and o-dichlorobenzene as solvents gave rate constants that increased as the swelling ability of the solvent increased. Swelling ratios were measured at 90 °C, the reaction temperature. 

The binding fluid can weaken the binder, as is seen with pectin when used with ethanol as the fluid. Ethanol reduces the swelling ability of pectin. 

The strong increase in mean particle diameter of the sieve fraction 1.0-0.5 mm. for the coal with 32.2% volatile matter cannot be explained on the basis of the relationships discussed. The unusually high swelling ability in this case is caused by a very high proportion of exinite (21%) in the sample and the correspondingly very small proportion of inertinite (9). 

Support-bound aldehydes or ketones can be reduced to alcohols under mild reaction conditions that are compatible with most supports and linkers. Typical reducing agents are sodium borohydride or diisobutylaluminum hydride, which can penetrate cross-linked polystyrene provided that a solvent with sufficient swelling ability is... 

Alternatively, if better quality data is required only for some small regions of the spectrum, then those regions alone can be scanned to shorten the time needed to obtain an acceptable signal to noise level. The ability to analyze small regions of a coal sample is important even for a single maceral type such as vitrinite. For example, substantial variations occur in the structure (10,11) and swell ability (12) of different microscopic areas of vitrinite from the same coal. 

The ODN adsorption onto cationic microgel poly(N-isopropylacrylamide) particles was reported to be dramatically affected by the salinity of the incubation medium [9] as illustrated in Fig. 6. The observed result was related to (i) the reduction in attractive electrostatic interactions between ODN molecules and the adsorbent and (ii) the drastic effect of ionic strength on the physico-chemical properties of such particles [17, 27]. In fact, the hydrodynamic size, the swelling ability, the electrokinetic properties, and the colloidal stability are dramatically affected by pH, salt concentration, and the medium temperature [27]. 

Krauland et al. [93] prepared the microparticles with thiolated chitosan (chitosan-TBA chitosan-4-thiobutylamidine conjugate) intended for nasal peptide delivery. During the preparation process microparticles were stabilized by the formation of inter- and intramolecular cross-linking via disulfide bonds. Chitosan-TBA microparticles were characterized by improved swelling ability and displayed 3.5-fold higher insulin bioavailability compared to unmodified chitosan microparticles. 

Chitosan, a biocompatible and biodegradable polycationic polymer with low toxicity, is known for its swelling ability and permeation-enhancing properties and represents a polymer of choice for the preparation of microspheres intended for nasal administration [74],... 

SOLIDOKOLL N does not become insoluble or lose it swell-ability as some natural products during the drying or thermosol process. 

The impregnation of wood with pyrolysis oils (by EN 113) decreases its hydrophilic properties mainly owing to the decrease in its swelling ability- The surface concentration of hydrophilic centres decreases negligibly. 

The colloidal characteristics of A -alkylacrylamide- or Af-alkylmethacrylamide-based particles are temperature related. In fact, the swelling ability, charge density, charge distribution, hydrophilic-hydrophobic balance, hydration and dehydration properties, particle size, surface polarity, colloidal stability, water content, turbidity, and electrokinetic and rheological properties are indis-cemibly temperature dependent. Such polymer particles can be used as a stimuli-responsive model for the investigation of colloidal properties and for theoretical studies. 

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