Thin films of ethyl polyhedral oligomeric silsesquioxane (ethyl-POSS) containing polymers at different compositions were chemically modified using laser irradiation at 157 nm. The irradiation caused photodissociation of C-O and C-H bonds followed by the formation of new chemical bonds. The content of Si-O and C-O bonds increased, as did the surface hardness. Vacuum ultraviolet (VUV) absorption, mass spectrometry, x-ray photoelectron spectroscopy, and atomic force microscopy imaging and indentation were used to evaluate the effects of the 157 nm irradiation. The chemical modification was restricted to a thin surface layer. The layer depth was determined by the penetration depth of the 157 nm VUV photons inside the thin copolymer layer. With prolonged VUV irradiation, the absorbance of the polymers increased, eventually becoming saturated. The chemical changes were accompanied by surface hardening, as evidenced by the increase in the Young’s modulus from 4 to 24 GPa due to glassification of the irradiated parts. The chemically modified layer acts as a shield against photodissociation and degradation of the deeper portion of the POSS polymer by VUV radiation. Applications include the protection of solar cells on low orbit satellites from solar VUV photons.
Relevant Publications
Surface modification of polyhedral oligomeric silsesquioxane block copolymer films by 157 nm laser light.,
E. Sarantopoulou, Z. Kollia, A. C. Cefalas, A. E. Siokou, P. Argitis, V. Bellas, and S. Kobe,
J. Appl. Phys. 105 (11), art. no. 114305 (2009).
DOI:10.1063/1.3131822
Effect of 193 and 157 nm laser light illumination on the surface properties of TMOS-NiCl2
sol-gel derived material.
L. Athanasekos, Z. Kollia, M. Vasileiadis, N. Aspiotis, D. Alexandropoulos, A. Meristoudi,
V. Karoutsos and E. Sarantopoulou,
J. Opt. 12, 124015 (2010).
DOI: 10.1088/2040-8978/12/12/124015
Self-assembled ferromagnetic and superparamagnetic structures of Fe block copolymers hybrids.
E. Sarantopoulou, J. Kovac, S. Pispas, S. Kobe, Z. Kollia and A.C. Cefalas,
Superlattices Microstr. 44 (4-5), 457 (2008).
DOI: 10.1016/j.spmi.2007.12.016
Dynamics and Laser Processing of Functional Fluoride Organic Surfaces at VUV Wavelengths.
E. Sarantopoulou, Z. Kollia, M. Chatzichristidi, A. Douvas A, P. Argitis , S. Kobe and A.C. Cefalas,
JLMN-Journal of Laser Micro/Nanoeng. 3, 24 (2008).
Surface modification of polymeric thin films with vacuum ultraviolet light.
E. Sarantopoulou, J. Kovac, Z. Kollia, I. Raptis, S. Kobe and A. C. Cefalas,
Surf. Interface Anal. 40 (3-4), 400 (2008).
DOI: 10.1002/sia.2776
Nano-modification of surface morphology of Teflon AF with VUV laser light.
E. Sarantopoulou,
Phys. stat. sol. A 204, 1843 (2007).
DOI: 10.1002/pssa.200675336
Micro/nano self-assembled 2D structures of block copolymer/Fe hybrids.
E. Sarantopoulou, K. Gatsouli, Z. Kollia, S. Pispas, S. Kobe, and J. Kovac,
Phys. stat. sol. A 204, 1835 (2007).
DOI: 10.1002/pssa.200675313
Nano-scale spatial control over surface morphology of biocompatible fluoropolymers at 157 nm.
E. Sarantopoulou, Z. Kollia, A.C. Cefalas, A. M. Douvas, M. Chatzichristidi, P. Argitis and S. Kobe,
Materials Science and Engineering C, 27, 1191 (2007).
DOI: 10.1016/j.msec.2006.09.044
Polymer self-assembled nano-structure and surface relief gratings induced with laser at 157nm.
E. Sarantopoulou, Z. Kollia, A. C. Cefalas, A. M. Douvas, M. Chatzichristidi, P. Argitis and S. Kobe,
Appl. Surf. Sci., 253, 7884 (2007).
DOI: 10.1016/j.apsusc.2007.02.071
Self assembled structures on fluoro-polymers induced with laser light at 157 nm.
Z. Kollia, E. Sarantopoulou, A.C. Cefalas, S. Kobe, P. Argitis and K. Missiakos,
Appl. Surf, Sci. 248 (1-4), 248 (2005).
DOI: 10.1016/j.apsusc.2005.03.043
Conference Presentations
Surface and chemical modification of PDMS thin films by 157 nm laser light.E. Sarantopoulou, Z. Kollia*, C. Riziotis and A.C. Cefalas,6th International Conference on Nanosciences & Nanotechnologies – NN09, Thessaloniki, Greece, July 13-15, 2009.
Surface modification properties of sol-gel and PDMS materials upon 193nm and 157 nm laser light illumination.
E. Sarantopoulou, Z. Kollia, L. Athanasekos*, M. Vasileiadis, N. Aspiotis and D. Alexandropoulos,
Emerging Trends & Novel Materials in Photonics, Delphi, Greece, October 7-9, 2009.
Self-assembled ferromagnetic and superparamagnetic structures of Fe block copolymers hybrids. (INVITED)
E. Sarantopoulou,
Women In Nano” Winter School. Kranjska Gora, Slovenia. 7-9 Februariou (2008).
Limits of hierarchical self-assembled nano/micro structures induced by vacuum ultraviolet light. (INVITED)
A. C. Cefalas, E. Sarantopoulou, Z. Kollia and S. Kobe,
Hot Nanotopics, Portoroz Slovenia, 23-30 May (2008).
Principles and methodologies of polymer nano/micro- fabrication with VUV ligth.
E. Sarantopoulou, Z. Kollia, M. Chatzichristidi, A. Douvas, P.Argitis, S. Kobe and A.C. Cefalas.
8th International Symposium on Laser Precision Microfabrication (2007).
Micro/Nano self-assembled structures of block copolymer / iron, samarium iron nanoparticles hybrid materials induced by VUV light.
E. Sarantopoulou, K. Gatsouli, Z. Kollia, S. Pispas, S. Kobe and A. C. Cefalas.
8th International Symposium on Laser Precision Microfabrication (2007).
Self -assembled magnetic structures of Fe polymers.
E. Sarantopoulou, K. Gatsouli, Z. Kollia, S. Pispas, A. C. Cefalas, S. Kobe and J. Kovac,
EMRS 2007, Strasburg France, May 28 – June 1, (2007).
Nano-depth control over self assembled structures on biocompatible polymeric thin films for bio array applications.
E. Sarantopoulou
TNT 2006 Grenoble France, 4-8 September (2006).
Polymer self-assembly with lasers at 157 nm.
E. Sarantopoulou, Z. Kollia, A. C. Cefalas , A. M. Douvas, M. Chatzichristidi, P. Argitis and S. Kobe,
EMRS 2006, Nice France, 29 May-2 June (2006).
Self assemply of fluor and other polymers with laser light at 157 nm.
Z. Kollia, E. Sarantopoulou, A. C. Cefalas and S. Kobe,
EMRS 2004, G-Current trends in nanoscience-from materials to applications,
Strasbourg France, May 24-28 (2004).
Self-assempled structures induced with laser light at 157 nm.
Z. Kollia, E. Sarantopoulou, A. C. Cefalas, S. Kobe, P. Argitis and K. Missiakos,
4th International conference on photo excited processes and applications, ICPEPA, Lecce Italy, 5-14 September (2004).