Intercalation composites

Table 4 shows the photocatalytic activity of CuOx supported on the pristine samples of layered titanates. The loading (26 wt% Cu) corresponds to the Cu/Ti ratio (0.33) for the composite prepared by the intercalation process. The two pristine layered titanates showed very low activity without loading CuOx. In contrast, the activity of the CuOx-loaded samples was quite different the protonated phase produced ca. 18-times higher rate of Ha evolution. Copper oxides in these materials were deposited only on the surface of the fibrous crystals. However, the protonated phase was decomposed to produce anatase-type TiOa as in the case of the intercalated composite (Fig. 5). This result also supports that the formation of anatase is essential for the photocatalytic activity. 

Intercalated composites in an intercalated composite the insertion of polymer into the clay structure occurs in a crystallographically regular fashion, regardless of the clay to polymer ratio. An intercalated nanocomposite is normally interlayered by only a few molecular layers of polymer and properties of the composite typically resemble those of ceramic materials. 

There are two basic types of nanocomposites, in which particles are intercalated or exfoliated. In an intercalated composite the nanodispersed filler still consists of ordered structures of smaller individual particles, packed into intercalated structures. Exfoliated particles are those dispersed into practically individual units, randomly distributed in the composite. Layered silicates, such as montmorillonite clays or organoclays, can be used in nanocomposites. Because clays are hydrophilic and polyolefines are hydrophobic, it is not easy to make a nanocomposite based on polyethylene or polypropylene because of their natural incompatibility. 

Bora, M. Ganguli, J. N. Dutta, D. K (2000). Thermal and spectroscopic studies on the decomposition of [Ni di(2-aminoethyl)amine 2]- and [Ni(2,2" 6",2"-terpyridine)2]-Montmorillonite intercalated composites Thermochimica Acta. Vol. 346, p.169-175. Ghang, M. Y. Juang, R. S. (2004). Adsorption of tannic acid, humic acid and dyes from water using the composite of chitosan and activated clay. Journal of Colloid and Interface Science. Vol. 278, pp.18-25. 

The influence of the nanocomposite structure on its flammability is reflected in the Table 7. One can see that the least flammability is observed in delaminated nanocomposite based on the polystyrene whereas the flammability of the intercalated composite is much higher [54]. 

The functionality of the thermoset polymers also plays a vital role in the formation of exfoliated or intercalated composites [32]. The XRD studies reveal the exfoliation of clay platelets at all clay concentration except 10 wt% when dispersed in bi-functional epoxy resin [32]. Whereas the tri-and tetra-functional epoxy resin results in formation of intercalated nanocomposites only, except at very low clay concentrations. 

Quatemized chitosan-organic rectorite intercalated composites based NPs For protein controlled release [189]... 

Xu R, Xin S, Zhou X, Li W, Cao F, Feng X, Deng H. Quaternized chitosan-organic rectorite intercalated composites based nanoparticles for protein controlled release. Int J Pharm. 2012 438(l-2) 258-65. 

L. C. Du, B. J. Qu, Y. Z. Meng, and Q. Zhu, Structural characterization and thermal and mechanical properties of polyCpropylene carbonate)/MgAl-LDH exfoliation nanocomposite via solution intercalation. Composites Science and Technology, 66 (2006), 913-18. 

Poly(propylene oxide) bis(2-aminopropyl ether) (PPO-NH2), hereafter called functionalized oligomers or organic oligomers, with a low molecular weight (230 g mof ) was purchased ftom Aldrich and used without further purification. PPO-NH2 protonated by addition of 10% HCl solution to obtain PPO-NH3CI. Montmorillonite clay was purchase from the Southern Clay Repository at Purdue University. The procedure to obtain intercalated composites is now described. The clay (0.4 g) was stirred for an hour in water and sonicated for further 30 minutes to obtain a suspension. The organic oligomers were added to the suspension which was subsequently sonicated for 30 minutes. Finally, water was removed by evaporation at 80°C. 

Xu, J. Hu, Y. Song, L. Wang, Q. Fan, W. Liao, G. Chen, Z. Thermal analysis of polyfvinyl alcohol)/graphite oxide intercalated composites. Polym. Degrad. Stab. 2001, 73, 29-31. 

TEM pictures indicated intercalated composites with the montmorillonite oriented in one direction. The antioxidant has weakly acidic phenolic functionalities associated with the molecule. These functionalities provide the potential for exchange at the edges of the organomontmorillonite. 

WAXS indicated an intercalated composite. The modulus values for the 5% loaded composite are indicative of an intercalated composite (a 12% increase above the pure polymer value of 8.66x10 Pa). A Halpin-Tsai calculation for a 3% loaded composite predicts a 63% increase in modulus for a fully exfoliated montmorillonite composite with the particles ahgned in the direction of applied stress. The unexpected result is the dramatic increase in percent elongation to failure... 

WAXS and TEM indicated intercalated composites. The composite with the highest modulus was prepared with Cloisite 25A (2984 Mpa versus 2170 MPa for the pure polymer). As expected, the percent elongation to failure decreased from 316.5% for the pure polymer to 30.6% for the composite. 

Elastomers (rubber) have the advantage of lower Tg than polymers for engineered applications and equipment uniquely designed for the preparation of rubber compounds that allows for the incorporation of much larger amounts of montmorillonite without a detrimental sacrifice of the hardness-flexibility balance of the nanocomposites. The alignment of intercalated composites for the maximum benefit of mechanical properties is much easier. 

Oyama et al. [719, 720] described a novel CP cathode made by mixing chemically polymerized P(ANi) with 2,5-dimercapto-l,3,4-tliiadiazole (DMcT) in A/-Me-2-pyrrolidinone solvent, and spreading and drying the resulting dark, viscous ink on a carbon film to obtain die active cathode. This cathode functioned as a Li ion reservoir, much in the tradition of the Li-intercalate composite electrodes and showed the following reactions ... 

Zheng, J.P., et al., 2007. Study on ibuprofen/montmoiiUonite intercalation composites as drug release system. Appl. Clay Sci. 36 (4), 297-301. http //www.sciencedirect.com/science/ article/pii/S0169131707000026 (accessed 21.02.16.). 

With clay and polymer, several types of composite are possible. A classic composite polymer does not enter the clay interlayers. If the polymer diffuses into the interlayers and the layers remain stacked, an intercalated composite is formed. If interplanar attraction is overcome and the silicate layers are separated, the composite is exfoliated. These different morphologies have a large impact on functional properties. Owing to the presence of water in the clay structure, the clay must be dried carefully. Montmorillonite (MMT) can be dried by annealing at 250°C for about 3 hours to remove water molecules from the interlayers. ... 

The voltage of a lithium intercalation battery varies with its state of discharge, i.e., the intercalant composition x. Subsequently more careful experiments have shown fine structure in V(x) for many intercalation system [4, 5, 7, 10] clearly observed in plots of dxIdV vs. x or V, which can be caused by a variety of physical mechanisms such as the interactions between intercalated atoms within the host or intercalation-induced stmctural phase transitions in the host. Therefore, careful measurements of dx/dV can be used a study the physics and chemistry of the intercalation process. 

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