Phase-separated macro-molecular

In one case (Method I), the organic component forms a phase-separated macro-molecular network, which is chemically bound to the surrounding inorganic domains (e.g., epoxy-based systems). 

Kuznetsov, Y.G. Malkin, A.J. McPherson, A. Atomic force microscopy studies of phase separations in macro-molecular systems. Phys. Rev. B. Condens. Matter 1998, 58 (10), 6097-6103. 

Dialysis separations are often used for removal of interferents in the sample matrix. The technique is based on differences in mobility of ionic or molecular constituents in a liquid phase during their transport across a semi-permeable membrane into a second liquid phase which need not be immiscible with the first. Mass transfer occurs between a donor phase and an acceptor phase separated by a membrane which selectively allows penetration of solutes by blocking the passage of macro-molecules or by differences in molecular diffusivities. The driving force of the mass transfer is the existence of a concentration gradient of the transferable solute between the two phases. 

An important factor to consider on the blending of polymeric materials is that most polymers are incompatible with polypropylene on the molecular scale. This might cause many problems, such as macro-phase separation during blending, low interface adhesion, low tensile transfer rate, and low physical properties, which may be even lower than the unmodified polymer. To sustain good fiber properties, controlling the phase structure and interface adhesion is a necessity. 

If a polymeric blend system is homogeneous (3), it can be linked to alloys of metals where components mix completely on a molecular scale. If it is heterogeneous, and form a two- or multi phase structure, depending on degree of phase separation there may be different phases either at macro or micro level (4). Heterogeneous blend systems are of growing interest, where, to utilize physical properties of the components efficiently a good stress-transfer between the components is essential hence, proper attraction and adherence of different components with each other is needed. 

CRA Craubner, H., Thermodynamic perturbation theory of phase separation in macro-molecular multicomponent systems. 2. Concentration dependence. Macromolecules, 11, 1161, 1978. 

Block copol3nners form a new class of molecular composite materials by the phase separation of incompatible hard and soft segments which form their macro-molecular structure. Thermoplastic elastomers where the soft segments form the continuous phase have been extensively investigated by means of an adsorption-interdiffusion (A-I) model for the interfacial phase which bonds the hard and soft phases. The molecular structure and rheological activity of the interfacial phase in thermoplastic elastomer block copolymers is shown to play a dominant role in nonlinear viscoelastic response, mechanical hysteresis and energy absorption. Creation of elastomeric microphases in epoxy structural adhesives has been recently identified with in situ block copol3nnerization between carboxy terminated nitrile (CTBN) rubber and the diepoxide. 

---