Semiconducting Cross-Linked Polymer Nanowires Prepared by High-Energy Single-Particle Track Reactions

Abstract

High-energy charged particle irradiation of cross-linking polymers gives nanowires formed by cross-linking reactions along the ion track trajectories. Here, the direct formation of nanowires consisting of a conjugated polymer by single-particle nanofabrication technique (SPNT) is investigated. Poly(9,9'-di-n-octylfluorene) (PFO), regioregular poly(3-hexylthiophene) (rrP3HT), and poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) underwent an efficient cross-linking reaction upon irradiation, resulting in the formation of 1-dimensional nanostructures with high and desired aspect ratio reaching up to ∼200. The size of nanowires was perfectly interpreted by well-sophisticated theoretical aspects based on the statistical theory of polymer backbone configurations, suggesting that simple cross-linking reactions of the polymers determine the size and structure of nanowires. PFO based nanostructures exhibited sharp and intense emission with high fluorescence quantum yield indicating the absence of any significant inter/intra polymer chromophore interactions in the nanowires assemblies.

The Photopolymer Science and Technology Award

“…The high density cross-linking provides not only the simple formation of the nano-wires but also the higher mechanical strength of the nano-wires than those reported by the same authors [10][11][12], suggesting the high feasibility of the present nano-wire systems for practical application utilizing their ultra-large surface areas. The control of the nano-wire alignment was also demonstrated finely in the present paper, and this is also the case of a seamless dimension control of nano-materials from 1-dimensional to 2-dimensional ones.…”

Nanowires for Renewable Energy

“…3.4, this in turn can be used to calculate G(x) from the evaluated nanowire radius. Accordingly, G(x) is expressed as [53] PC 61 BM PC 71 BM C 60 ICBA 500 nm The validity of this equation has been proved for many types of polymers [41][42][43]. The typical G(x)s among synthetic polymers is ranging from 0.30 to 1.6 (100 eV) −1 [54].…”

“…6.2). Although many types of conjugated polymer nanowires have been successfully formed by SPNT [41][42][43][44], its applicability to conjugated molecules has remained elusive, because organic molecules require a large number of cross-linking reactions to ensure insolubility against the developer. However, fullerenes were found to form nanowires, owing to unprecedentedly high cross-linking efficiency.…”

High-Energy Charged Particles

“…Accordingly, G(x) is expressed as [53] The validity of this equation has been proved for many types of polymers [41][42][43]. 3 is useful for quantitative analysis of nanowire radius (r) on the basis of a given cross-linking efficiency, G(x).…”