Polymer-Like Flexibility and Growth Kinetic in Inorganic Nanowires

We recently reported on the gram-scale synthesis of ultrathin (1.6 nm core diameter) inorganic colloidal nanowires which, besides having remarkable optical properties, they appeared to be unusually flexible. We here explore quantitatively the analogy between these ultrathin inorganic nanowires and polymers, by multi-angle light scattering. We show that: (i) these nanowires grow exclusively in length and they can reach contour lengths of hundreds of microns, while retaining a 1.6 nm core diameter, thus reaching aspect ratios of 10⁵; (ii) their scattering spectrum was modeled by a worm-like chain model with a Kuhn length of 35 nm (intermediate between the one of single stranded and double stranded DNA); (iii) their growth kinetic was modeled by a combination of growth at the tips and end-to-end attachment, similarly to some step growth polymerization mechanisms. On the basis of these results we suggest that these ultrathin colloidal nanowires might represent a first candidate of a class of materials at the intersection between polymers and nanowires .