Artificial nanocomposites

Hence, this chapter results demonstrated common reinforcement mechanism of natural and artificial (filled with inorganic nanofiller) polymer nanocomposites. The statistical segments number per one nanocluster reduction at nanofiller contents growth is such a mechanism on suprasegmental level. The indicated effect physical foundation is the densely packed interfacial regions formation in artificial nanocomposites. 

And in eompletion of the present seetion let us note one more important feature of natural nanocomposites structure. In Refs. [24,25] the interfacial regions absence in amorphous glassy polymers, treated as natural nanocomposites, was shown. This means, that such nanocomposites structure represents a nanofiller (nanoclusters), immersed in matrix (loosely packed matrix of amorphous polymer structure), that is, unlike polymer nanocomposites with inoiganic nanofiller (artificial nanocomposites) they have only two structural components. 

Hence, the presented above results have shown that elasticity modulus of amorphous glassy polycarbonate, considered as natural nanocomposite, are defined completely by its suprasegmental structure state. This state can be described quantitatively within the frameworks of the cluster model of polymers amorphous state structure and characterized by local order level. Natural nanocomposites reinforcement degree can essentially exceed analogous parameter for artificial nanocomposites [56]. 

As it has been shown above (see the Eqs. (15.7) and (15.15)), the nanocluster relative fraction increasing results to polymers elasticity modulus enhancement similarly to nanofiller contents enhancement in artificial nanocomposites. Therefore, the necessity of quantitative description and subsequent comparison of reinforcement degree for the two indicated above nanocomposites classes appears. The authors of Ref. [58, 59] fulfilled the comparative analysis of reinforcement degree by nanoclusters and by layered silicate (organoclay) for polyarylate and nanocomposite epoxy poly-mer/Na" —montmorillonite [60], accordingly. 

In the stated above treatment not only nanostructure integral characteristics (macromolecular entanglements cluster network density v, or nanocluster relative fraction cp j), but also separate nanoeluster parameters are important (see Section 15.1). In this case of particulate-filled polymer nanocomposites (artificial nanocomposites) it is well-known, that their elasticity modulus sharply increases at nanofiller particles size decrease [17]. The similar effect was noted above for REP, subjected to different kinds of processing (see Fig. 15.28). Therefore, the authors of Ref. [73] carried out the study of the dependence of elasticity modulus E on nanoclusters size for REP. 

Zhao, J., Jedlicka, S. S., Larmu, J. D., Bhunia, A. K., and Rickus, J. L. (2006). Liposome-doped nanocomposites as artificial cell-based biosensors Detection of listeriolysin O. Biotechnol. Prog. 22,32-37. 

Recently, La Mantia et al reported a study of LLDPE/clay nanocomposites with appropriate additives [103], The photochemical behavior of nanocomposites without and with different UV stabilizers was studied under artificial accelerated conditions of ageing. Addition of a metal deactivator to the LLDPE-clay nanocomposites was also compared. Stabilizing effect on the physical properties such as elongation at break and tensile strength were described. The most effective photostabilization of these LLDPE/clay nanocomposites was achieved in presence of the metal deactivator. 

In a series of papers, Jeschke and coworkers [87-90] as well as Schlick and coworkers [91, 92] studied self-assembled nanocomposite materials made from polymers and natural clays or artificial silicates. These nanocomposite materials have superior mechanical and also heat resistant properties and are hence interesting for applications in the fields of defense and protection. Such polymer-inorganic hybrid materials form complex stmctures and EPR spectroscopy has to be combined with other physical techniques such as NMR spectroscopy, small and... 

Shahinpoor M, Kim KJ, Mojarrad M (2007) Artificial muscles applications of advanced polymeric nanocomposites. CRC Press Taylm Francis Group, Boca Raton Carpi F, Smela E (2009) Biomedical applications of electroactive polymer actuators. Wiley, Chichester... 

Fig. 10.10 a Macroscopic structure and b complex 3D folding behavior of the device composed of bilayer structure CNT/LCPs nanocomposite and PC. c Reversible folding and unfolding behavior of the artificial arm based on CNT/LCPs nanocomposite and PC. d-g Grip irregular shape objects with this artificial arm in the condition of air and water. Reproduced with permission from [46]. Copyright 2013... 

Recently, the production of nanofibres using nanocomposites has attracted attention. This is due to the fact that this type of nanofibre combines the unique properties of nanocomposites with the outstanding characteristics of nanofibres. Metal/polymer nanocomposites have not only the potential to meet the requirements of applications such as photonic and electric sensors, filters, and artificial tissue, but also can act as catalysts. Silver nanoparticles are the most common embedded metal nanoparticles used in conjunction with polymers. This is because silver nanoparticles exhibit remarkable properties including catalytic activity, surface-enhanced Raman scattering activity, high electrical conductivity and antimicrobial activity. 

Schumann DA, Wippermaim J, Klemm DO et al (2009) Artificial vascular implants frran bacterial cellulose preliminary results of small arterial substitutes. Cellulose 16 877-885 Seydibeyoglu MO, Oksman K (2008) Novel nanocomposites based on polyurethane and micro-fibrillated cellulose. Compos Sci Technol 68 908-914 Shoda M, Sugano Y (2005) Recent advances in bacterial cellulose production. Biotechnol Bioprocess Eng 10 1-8... 

Chemically bonded scaffolds are superior to physically adsorbed scaffolds in terms of the robustness of the resulting gold nanocomposites. Although most polymers introduced by the grafting from method are artificial polymers [80, 81], representative biopolymers such as oligonucleotides and peptides can also be introduced. 

On the other hand, single-wall CNTs (SWCNTs) can efficiently absorb and convert photon energy into thermal energy and have excellent thermal conductivities. Thus, they can act as a nanoscale heat source and thermal conduction pathway to heat the crosslinked LCP matrix effectively [51]. Furthermore, the resultant crosslinked PLCP/SWCNT nanocomposites exhibited effective photoactuation not only by white light but by near-IR irradiation as well [52]. Such nanocomposites were used to direct sun-driven artificial heliotropism for solar energy harvesting [53]. 

Li, C. Liu, Y. Huang, X. Jiang, H. Direct sun-driven artificial heliotropism for solar energy harvesting based on a photo-thermomechanical hquid-crystal elastomer nanocomposite. Funct. Mater. 2012. D01 10.1002/adfm.201202038... 

---