Molecular combing of a flexible polymer chain by simple spin-casting

Abstract

If polymer chains could be fixed on a substrate as a fully elongated chain, a procedure known as "molecular combing", the chain structure could be analyzed more precisely than has been possible with the characterization techniques available today. Although the molecular combing of a rigid biomolecule, DNA, has been attained for the mapping of genetic information, that of flexible chains has never been achieved as yet. We show here that poly(n-nonyl acrylate) (PNA) can be molecularly combed on mica by a simple spin-casting method, and that the chain lengths were in good agreement with that of the all-Trans conformation. One of the key factors for successful molecular combing was found to be the weak adsorption of PNA on mica, indicating that flexible polymers may be molecularly combed by adjusting their affinity to the substrate. The molecular combing of polymer chains may open a new way not only to characterize the chain structures more precisely but also to fabricate new nanomaterials based on polymers.