Vincent Roucoules

Nanopatterning of plasma polymer reactive surfaces by DUV interferometry

A new method is described for producing patterned solid surfaces with reactive groups. This entails pulsed plasma deposition of anhydride functionalized films, followed by the covalent attachment of an amine-terminated nucleophile via aminolysis reaction. Characterization of the surface chemistry was achieved by XPS, PM-IRRAS and contact angle measurement. Patterning was achieved by DUV irradiation using an ArF excimer laser and an interferometric set-up. Well-defined patterns have been obtained at different scales on a large surface area and using this unique procedure. Spectroscopic characterizations coupled with AFM measurements allow explanation to some measure of the photoinduced phenomena. Trenches with a width ranging from 75 to 500xa0nm and a depth up to 30xa0nm were written. Using this approach it is possible to create combinatorial patterned surfaces with well-controlled topography and chemistry.

Role of Cellulose Nanocrystals on the Microstructure of Maleic Anhydride Plasma Polymer Thin Films

Recently, it was shown that the microstructure of a maleic anhydride plasma polymer (MAPP) could be tailored ab initio by adjusting the plasma process parameters. In this work, we aim to investigate the ability of cellulose nanocrystals (CNCs) to induce topographical structuration. Thus, a new approach was designed based on the deposition of MAPP on CNCs model surfaces. The nanocellulosic surfaces were produced by spin-coating the CNC suspension on a silicon wafer substrate and on a hydrophobic silicon wafer substrate patterned with circular hydrophilic microsized domains (diameter of 86.9 ± 4.9 μm), resulting in different degrees of CNC aggregation. By depositing the MAPP over these surfaces, it was possible to observe that the surface fraction of nanostructures increased from 20% to 35%. This observation suggests that CNCs can act as nucleation points resulting in more structures, although a critical density of the CNCs is required.

Influence of Covalent Bonds on the Adhesion Energy at Elastomer-Glass Interfaces

The aim of this study was to analyze the effect of interfacial covalent bonds on the adhesive behavior of an elastomer, a crosslinked polydimethylsiloxane, and a glass substrate. These covalent bonds were created by applying to both materials an appropriate surface treatment by means of plasma polymerization. Adhesion measurements were carried out by analyzing the contact area between a rubber hemisphere and a flat rigid glass plate. The contact was forced under a given compressive loading for different times tc, then the load was removed and the fracture propagation at the interface was recorded as a function of relaxation time tr. Finally, adhesion energies were also determined by means of a probe test using a tensile testing machine.

Investigation of Nanopatterned Functional Polymer Surfaces by AFM in Pulsed Force Mode

Achieving topography and chemistry control at the nanoscale of polymer surfaces constitutes a highly challenging objective in nanotechnology. Advances in this field suppose the development of characterization methodology with sub-100-nm resolution. Many imaging techniques based on scanning probe microscopy (SPM) were recently developed to achieve this goal [1]. Among them, pulsed force mode (PFM) atomic force microscopy (AFM), which has been proposed firstly by Marti [2], is still a method of interest since this nonresonant mode designed to allow approach curves being recorded along the scanning path provides the topography of the sample and a direct and simple local characterization of adhesion and stiffness.This chapter is aimed at demonstrating the interest of this technique to investigate polymer surfaces patterned with photochemical methods. Both topography and chemical contrast at the sub-100-nm scale can be probed, which gives new insights into photoinduced processes at the nanoscale.After an introduction focusing on the main techniques used for the analysis of the chemical contrast at micro- and nanopatterned polymer surfaces, the first part will deal with the utility of AFM in the investigation of photopolymer surfaces.In the second part, the principle of PFM and its interest in polymer surface analysis will be detailed.The third part will focus on a recent application dealing with the nanopatterning of plasma polymer surfaces using DUV photolithography techniques. Analysis of interactions between the AFM tip and the polymer surface allows acquiring relevant information on the light-induced modifications at the nanoscale.