Dynamic swelling experiments

In a similar approach Riihe et al. [279] reported the preparation ofpoly(2-oxazoline) brushes by the grafting onto as well as grafting from method. For LCSIP of 2-ethyl-2-oxazolines silane functionalized undecane tosylate was first prepared and then immobilized on the substrate surface. SIP resulted in PEOx layers with thickness close to 30 nm. PEOx brushes were prepared by chemisorption of PEOx disulfides onto gold substrates. Preliminary static and dynamic swelling experiments are reported for these brushes. However, later observations [243] contradicted these findings. 

In addition to the above techniques, inverse gas chromatography, swelling experiments, tensile tests, mechanical analyses, and small-angle neutron scattering have been used to determine the cross-link density of cured networks (240—245). Si soHd-state nmr and chemical degradation methods have been used to characterize cured networks stmcturaHy (246). H- and H-nmr and spin echo experiments have been used to study the dynamics of cured sihcone networks (247—250). 

The rate and characteristics of swelling play an important role in the characterization of polymers. However, in traditional swelling experiments, detection of the swelling front and investigations of its influence on the polymer dynamics are difficult, while the characterization of these features plays a significant role in distinguishing between so-called Case I or Fickian and Case 11 diffusion [134]. 

IR based nanocomposites. In situ silica was prepared in IR with the solution process.Swelling experiments evidenced good polymer-filler adhesion, in the presence of coupling agents. The dynamic-mechanical behaviour was found to be increasingly non-linear for silica contents higher than 20 wt%. 

Additional insights into the dynamics and structure of bimodal elastomers have been obtained by dynamic light-scattering experiments [129], neutron scattering experiments [130] and calculations [131], dual cross-linking system experiments [132], non-affine swelling [133], and the computer simulations already mentioned. 

Introduction of HM mixture induced passive permeability of mitochondria membranes for K, and resulted in aggravation of proton permeability (Fig. 22.3). Statistically significant differences in swelling rate of mitochondria isolated from the rat liver between different animal groups, was observed in ammonium nitrate medium from the second minute tiU the end of the experiment. Similar dynamics... 

During the friction measurement, a test tube containing a small piece of gel is placed in the same water bath and the appearance of the gel is continuously monitored. The decrease of the diameter of the free gel from the isochore diameter is less than 10% at the highest temperature of the present friction experiment. This observation confirms that the gel swelling or shrinking as a whole should not have a significant effect on the friction measurement. A slight opacity of the gel develops in the gel in the vicinity of the temperature at which the friction of the gel diminishes and is presumably due to the dynamic density fluctuations. 

Figure 5. Dynamic mechanical and swelling behavior for a transient moisture sorption experiment on DGEBA-TETA.

---