Karbon nanotüp katılmış H-bağlı çokkatmanlı örtülerin döndürme yöntemi ile katmerli yapılandırılması

Various inorganic materials have been incorporated in organic multilayers using electrostatically-driven layer-by-layer (LbL) nanotechnology. However, weak interactions such as H-bondings, pi-pi stackings, and hydrophobic effects have not been employed as much as electrostatic forces in organic-inorganic hybrid LbL systems. This thesis introduces new procedures to prepare pristine carbon nanotube (CNT) containing LbL nanocomposites using weak intermolecular interactions and investigates the factors affecting the multilayer growth and the pH-stability of resulting films. The central idea is to noncovalently stabilize CNTs in assembly solutions of H-bonded multilayer (hb-multilayer) films in which polyvinylpyrrolidone (PVPon) is H-bonding acceptor and tannic acid (TA) is H-bonding donor. Single-wall CNTs (SWCNT) were first dispersed in aqueous TA solutions (resulting in TA-SWCNT) taking advantage of pi-pi stackings between aromatic moieties of TAs and pi-conjugated surfaces of CNTs. Buffering agents were not used in assembly solutions/dispersions because pristine CNTs aggregate in the presence of cations. Also, the usage of branched polyethyleneimine (BPEI) as an anchoring layer was avoided considering potential bioapplications. We used spin-assisted LbL (spin-LbL) for assembling hb-multilayers because it is faster compared to dip-assisted LbL (dip-LbL) and also requires less solutions/dispersions. In spin-LbL of BPEI-free multilayers, the multilayer growth profiles showed exponential-like initial phase followed by linear growth in the presence and absence of SWCNTs. We further examined this observation by studying dip- and spin-LbL of CNT-free PVPon/TA multilayers. Control experiments using dip-LbL showed zigzag-like exponential growth independent of the factors of BPEI, pH, and ionic strength. These observations differ from previously reported growth profiles of dip-LbL of (BPEI)(PVPon/TA)n which showed zigzag-like linear growth. Both the growth profiles and pH-stabilities of (PVPon/TA)n spin-multilayers showed significant dependence on the timescale of film deposition and pH-dependent disintegration processes. The differences were discussed in terms of kinetic trap of molecules in less favorable conformations in spin-assembled multilayers. Then, we prepared PVPon-functionalized SWCNT dispersions (resulting in PVPon-SWCNT) which are thought to be governed by a combination of charge-transfer interactions, hydrophobic effects, and weak H-bondings. As a next step of our previous efforts, various combinations of SWCNT-doped hb-multilayers were prepared and characterized: (PVPon-SWCNT/TA)n, (PVPon/TA-SWCNT)n, and (PVPon-SWCNT/TA-SWCNT)n. We successfully incorporated SWCNTs in hb-multilayers without sacrificing film stability using a combination of two different noncovalent functionalization routes and LbL technique. When the contact times of assembly fluids and growing films are minimized, growth profiles of SWCNT-doped hb-multilayers all showed perfectly linear growth. This suggests that well-defined bilayers having uniform thickness, less surface roughness, and reduced interdigitation between layers are obtained as a result of spin-LbL. The higher pH-stability observed for (PVPon-SWCNT/TA-SWCNT)n multilayers was mainly attributed to the hydrophobic stabilization of multilayers by CNT-CNT interactions. PVPon/TA pair is important for biomedical applications and SWCNTs are promising pharmaceutical excipients. The SWCNT-doped hb-multilayers introduced in this thesis have great application potential as novel biomaterials.