Organoclay exfoliation

Nanohybrids can be prepared in the form of intercalated layered nanocomposites produced by co-assembly of guest biomolecules in the presence of exfoliated organoclay sheets (Section 8.4), or by wrapping single biomolecules in ultrathin layers of condensed organoclay oligomers (Section 8.5). Such approaches should provide new general routes towards the development of functional biomaterials with numerous applications. 

Reinforcement of the epoxy-clay nanocomposites was also dependent on the clay loading as shown in Fig. 29. Thus for epoxy CH3(CH2)17NH3+-MMT nanocomposite system, the tensile strength and modulus increased nearly linearly with clay loading. More than a tenfold increase in strength and modulus could be realized by the addition of ca. 15 wt % of the exfoliated organoclay. 

Fig. 13.12 Polymer nanocomposites containing spherical silica nanoparticles in vinyl ester (left) and exfoliated organoclay...

The authors [2] considered some aspects of nanofiller (organoclay) structure influence on nanocomposites flame-resistance. Firstly, the nanocomposite with exfoliated organoclay possesses higher flame-resistance, than... 

For further calculations as the first approximation 6 =1 was accepted, that corresponds to perfect adhesion by Kemer [4], In Fig. 11.1, the dependence of heat release maximum rate on the sum of nanofiller (organoclay) and interfacial regions relative volume contents is adduced, calculated according to the Eqs. (3) and (4) for intercalated and exfoliated organoclay, respectively. As one can see, all data correspond to one curve, which extrapolates to d 1450 kw/m at ((p +(pp=0, that is, for unfilled polymer. This value corresponds to the indicated parameter mean value for the four matrix pol5miers, mentioned above. The sole essential deviation from the obtained curve is the data for nanocomposite on the basis of PP. This deviation can be due to the condition b= for all considered nanocomposites. The value b can be estimated more precisely with the aid of the following percolation relationship [4] ... 

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