Surface Forces Study on Metal-Polymer Adhesion: 2

Abstract

To design functional materials based on composite materials, it is imperative for us to understand the mechanism of adhesion between different materials such as metal and polymer. In this study, we investigated the adhesion between NiCr alloy film with three different compositions Ni100, Ni90Cr10, Ni60Cr40 and polyimide film using surface forces apparatus combined with optical microscope, which enable the observation of contact area during the measurement of the adhesion. This composite is widely used in the electronic devices as substrates, wiring, etc. The adhesion force measured in air for Ni90Cr10 and Ni60Cr40 decreased by time while that for Ni100 remained constant. In the measurement under nitrogen gas atmosphere, the order of strength became Ni60Cr40 Ni90Cr10 Ni100, and the decrement in adhesion for Ni90Cr10 and Ni60Cr40 was reduced. These results indicated that the Cr has stronger interaction with polyimide compared to Ni, and enhance the adhesion with polyimide. This was also supported by the larger hysteresis in the contact area vs normal load for Ni60Cr40 and Ni90Cr10 surfaces. However, Cr can be oxidized easily by exposure to air, which resulted in the decrease in the adhesion.

Molecular Architecture Studied by the Surface Forces Measurement

“…It is generally easier to analyze the forces between two identical surfaces, though similar modulation is possible for AFM. (4) The relatively easier modification of samples by various techniques including sputtering and spin-coating because sheets can be easily modified and glued on cylindrical lenses, which are most common geometry of SFA. Despite these advantages, the applicability of the measurement to only transparent samples by the conventional apparatus has been regarded as very serious, which limits its broader applications …”

Force Estimation on the Contact of Poly(l,l-lactide) and Poly(d,d-lactide) Surfaces Regarding Stereocomplex Formation

“…Adhesion forces between polymer films deposited on mica substrates were directly measured using SFA equipped with an optical microscope as previously reported (Figure ). , After the spin-coating of polymer, a cylindrical disk was fixed to an upper lens holder, and the other disk was fixed to a lower lens holder which was connected to a pulse motor stage (M-111.12S, PI Japan) via a horizontal spring (spring constant, k = 241 N/m). The surface separation distance and the normal load were controlled by the pulse motor drive.…”

“…30 We have used SFA for studying the adhesion forces between polyimide film and Ni/Cr alloy surfaces. 31,32 SFA has advantages for studying adhesion forces. The contacting area such as shape and roughness changes can be directly monitored using an optical microscope.…”

“…SFA has been used for studying the adhesion force between polymer films of micrometer level thickness such as poly­(ethylene terephthalate), poly­(butyl methacrylate), polystyrene, and poly­(dimethylsiloxane) . We have used SFA for studying the adhesion forces between polyimide film and Ni/Cr alloy surfaces. , SFA has advantages for studying adhesion forces. The contacting area such as shape and roughness changes can be directly monitored using an optical microscope. , The contact area vs load relation can be analyzed to provide the adhesion and surface energies, and their changes during the contact using a theory of adhesion such as JKR (Johnson–Kendall–Roberts) or DMT (Derjaguin–Muller–Toporov). , Therefore, SFA can be a quite useful tool for studying the interaction forces involved in the selective interaction of PLLA and PDLA.…”

“…We have used SFA for studying the adhesion forces between polyimide film and Ni/Cr alloy surfaces. , SFA has advantages for studying adhesion forces. The contacting area such as shape and roughness changes can be directly monitored using an optical microscope. , The contact area vs load relation can be analyzed to provide the adhesion and surface energies, and their changes during the contact using a theory of adhesion such as JKR (Johnson–Kendall–Roberts) or DMT (Derjaguin–Muller–Toporov). , Therefore, SFA can be a quite useful tool for studying the interaction forces involved in the selective interaction of PLLA and PDLA.…”