Researchers have analysed the properties of an organic polymer with potential applications in flexible electronics and uncovered variations in hardness at the nanoscale, the first time such a fine structure has been observed in this type of material.

The field of organic electronics has benefited from the discovery of new semiconducting polymers with molecular backbones that are resilient to twists and bends, meaning they can transport charge even if they are flexed into different shapes. [1],

Figure 1. ‘Fruitcake’ structure observed in organic polymers

Figure 1 shows it had been assumed that these materials resemble a plate of spaghetti at the molecular scale, without any long-range order. However, an international team of researchers found that for at least one such material, there are tiny pockets of order within. These ordered pockets, just a few ten-billionths of a metre across, are stiffer than the rest of the material, giving it a ‘fruitcake’ structure with harder and softer regions. [2]

The researchers used an imaging technique called higher eigenmode imaging to obtain nanoscale images of order regions in a semiconductor polymer called indacenodithiophene-co-benzothiadiazole (C16-IDTBT). These images clearly show how the individual polymer chains line up next to each other in some areas of the polymer film. These order regions are 10 to 20 nanometers in diameter. [3]

Further measurements of the stiffness of the material on the nanoscale showed that the areas where the polymers self-organised into ordered regions were harder, while the disordered regions of the material were softer. The experiments were performed in ambient conditions as opposed to an ultra-high vacuum, which had been a requirement in earlier studies.

"Organic polymers are normally studied for their applications in large area, centimetre scale, flexible electronics," said Venkateshvaran. "Nanomechanics can augment these studies by developing an understanding of their mechanical properties at ultra-small scales with unprecedented resolutions. [4]

References:

1. https://www.eurekalert.org/news-releases/954529
2. https://techiai.com/fruitcake-structure-observed-in-organic-polymers/
3. https://timetotimes.com/fruitcake-structure-observed-in-organic-polymers-3/
4. https://www.sciencedaily.com/releases/2022/06/220602095113.htm

Cite this article:

Thanusri swetha J (2022), ‘Fruitcake’ structure observed in organic polymers, Anatechmaz. pp.141