Ümit TAYFUN

Polymer Science & Technology

There are limitations in the applications of nanomaterials because of their restricted behaviour in different solvents

Surface modifications of nanomaterials help to tune their properties to suit different applications in the field of nanotechnology, because surface properties determine the interaction among the components, as well as the solubility and agglomeration behaviour in different solvents

Chemical modification of nanoparticle surface

Main aim is to make nanomaterial;To gain Hydrophilic, hydrophobic, conductive or anticorrosive properties

Development of multi-functional hybrid coating for scratch andcorrosion resistance: inorganic (nanoparticle) and organic component(active site)

• Functionalized nanoparticles can be applied in different areas:engineering, medical, biological, etc.Its necessary optimize the active sites on the nanoparticle surface(hydrophilic, hydrophobic, conductive etc)

• NMR (Nuclear Magnetic Resonance) spectroscopy 1H and 13C;

• FTIR (Fourier Transform Infrared in the transmission mode at400 – 4000 cm-1 – degree of modification of the nanoparticles;

• RAMAN SPECTROSCOPY

• TEM (Transmission Electron Microscopy) images – effect ofmodification of nanoparticles on their dispersion properties;

• EIS (Electrochemical Impedance Spectroscopy) – estimate thecorrosion protection performance of the prepared coatings

FTIR VIBRATION SURFACE CHARACTERIZATION

TRANSMISSION ELECTRON MICROSCOPY

Aggegation size

• Relatively dispersed at the scale of100 – 170 nm

•Some aggregates particles can beobserved (-OH: hydrogen bonding)

A – aminopropyl trimethoxy silane (APS)B – untreated ZrO2 nanoparticlesC – APS – treated ZrO2 nanoparticles

Development of nanotechnology-based organic coating to enhanceanticorrosion properties (incorporation of nanoparticles)

• The improvement in the properties of the nanocoatings is attributedto their nanoparticles functionalized ;

• Nanomaterials mostly used in coating system: SiO2, TiO2, ZnO,Al2O3, Fe2O3, nano-aluminum, nano-titanium

Improvement of UV-Blocking Coatings•Inorganic nanoparticles, as alternative to UV-blockers in coating applications•Nano-ZnO, nano-TiO2, nano-CeO2 : excellent photo- and thermal stability

•Example: transparent ZnO/epoxy nanocomposite coating via in situpolymerization. Optical properties of the nanocomposite coating depends onZnO particle size

Development of transparency and wear resistance

•The interface between particle and polymer matrix plays an important role as a well integrated filler provides better mechanical reinforcement

•When grafted with silanes having a reactive group, particles can be boundcovalently to the polymer matrix via silane surface modification

E. Barna et al, Surface Modification of Nanoparticles for Scratch Resistant Clear Coatings, 2007

Development of Super-Hydrophobic coatings

•Continuous demand for water-repellent or hydrophobic coatings in industry

Improvement of colloidal stability of nanoparticles •Attractiveness between the grafted polymer and the silica material

In image (a), the silica particles have similar colloidal shape and size, with near-monodispersed. In image (b), the polymer-grafted silica nanoparticles are further apart. This indicates that thick layers of hydrophilic methacrylate material were formed

Perruchot, Cat al., Synthesis of Well-Defined, Polymer-Grafted Silica Particles by Aqueous ATRP. Langmuir 2001

Fullerene and CNT functionalization

•For improvement of reactivity and adhesion properties

FullereneFullereneChemically Chemically Modified Modified FullereneFullerene

C60 C60(OH)24

Sayes et al., NanoLet, 2004Sayes et al., NanoLet, 2004

Phospholipid-coated SWCNTPhospholipid-coated SWCNT

Perruchot, C.; Khan, M. A.; Kamitsi, A.; Armes, S. P.; von Werne, T.; Patten, T. E., Synthesis of Well-Defined, Polymer-Grafted Silica Particles by Aqueous ATRP. Langmuir 2001, 17 (15), 4479-4481.

Siegel, R.H.; Hue, E.; Cox, D.; Goronkin, H.; Jelinski, L.; Koch, C.; Mendel, J.; Roco, M.; Shaw, D. R & D Status and Trends in Nanoparticles. Nanostructured materials, and nanodevices in the United States. WTEC Proceedings, International Technology Institute, Baltimore, Maryland, 1998; 1–233.

C. Zilg, R. Mu¨lhaupt and J. Finter, Macromolecular Chemistry and Physics 200 (1999) 661.

B. Wetzel, F. Haupert and M. Qiu Zhang, Composites Science and Technology 63 (2003) 2055.

E. Barna, D. Rentsch, B. Bommer, A. Vital, Surface Modification of Nanoparticles for Scratch Resistant Clear Coatings, Raw Materials, 2007

F. Bauer, H.-J. Glasel, U. Decker, H. Ernst, A. Freyer, E. Hartmann, V. Sauerland and R. Mehnert, Progress in Organic Coatings, 47, 2003, 147.

N. Nakashima, Y. Tomonari, H. Murakami, “Water-soluble single-walled carbon nanotubes via noncovalent sidewall functionalization with a pyrene-carrying ammonium ion”, Chem. Lett. 6, 638-639, 2002

Jung Tae Park , Jin Ah Seo, Sung Hoon Ahn, Jong Hak Kim, Sang Wook Kang, Surface modification of silica nanoparticles with hydrophilic polymers, Journal of Industrial and Engineering Chemistry 16 (2010) 517–522

Iijima, M., Tsukada, M. and Kamiya, H., Effect of particle size on surface modification of silica nanoparticles by using silane coupling agents and their dispersion stability in methylethylketone, J. Colloid Interface Sci., 307, 2007, pp.418-424