Lamellar orientation on the surface of a polymer determined by ToF-SIMS and AFM

The fold and lateral surfaces of chain-folded lamellae of poly(bisphenol-A-co-etheroctane), containing both aliphatic CH₂ and aromatic segments, were investigated by time-of-flight secondary ion mass spectrometry (ToF-SIMS). At low and high crystallization temperatures, the surfaces of the polymer films were shown to consist mainly of edge-on and flat-on lamellae, respectively. Surfaces with a mixture of edge-on and flat-on lamellae were produced at intermediate temperatures. The edge-on and flat-on lamellae were identified by using ions that recognize the flexible and rigid segments of the polymer. Ion images produced using selected ions that are related to the edge-on or flat-on orientation can be used to identify the location of these lamellae on the polymer surface. Our results indicate that ToF-SIMS can be used to detect different lamellar orientations at the surfaces of semi-crystalline polymers.     

Surface-Enhanced Infrared Spectral Investigations of 2,3-Bis(chloromethyl)anthracene-1,4,9,10-tetraone on Copper Nanoparticles

ABSTRACT

Surface-enhanced infrared (IR) absorption spectroscopic technique has been employed to investigate the orientation of 2,3-bis(chloromethyl)anthracene-1,4,9,10-tetraone (BCMAT) on copper nanoparticles (NPs). Copper NPs have been prepared by the chemical reduction method. The observed ring stretching modes show higher downshifts, broader bandwidths, and higher enhancement. The observed features in out-of-plane and in-plane CH deformation modes indicate that the BCMAT molecules may be adsorbed in a “flat-on” orientation on the copper NPs. The observed lower enhancement factor of the in-plane C?O deformation mode and C?O stretching mode and the higher enhancement factor of out-of-plane C?O deformation mode elucidate that the BCMAT molecules are adsorbed on the copper NPs in a “flat-on” orientation. All these observations show that BCMAT is adsorbed on copper NPs through the π-anthraquinone ring system in a “flat-on” orientation.