AsianScientist (May 8, 2019) – Nata de coco may be a delicious dessert, but researchers in Japan have found a way to turn it into a material for optical displays. Their findings are published in the journal ACS Macro Letters.
Cellulose, a naturally occurring polymer, consists of many long molecular chains. Because of its rigidity and strength, cellulose helps maintain the structural integrity of the cell walls in plants. It makes up about 99 percent of the nanofibers that comprise nata de coco, and helps create the unique and tasty texture of the dessert.
In this study, a team at Osaka University, Japan, has determined the optical parameters of cellulose molecules with unprecedented precision. The researchers first obtained unidirectionally-aligned cellulose nanofiber films by stretching hydrogels from nata de coco at various rates.
Nata de coco nanofibers allow the cellulose chains to be straight on the molecular level, and this was helpful for the precise determination of the intrinsic birefringence of fully extended polymer chains, said the researchers, explaining that birefringence describes how a material reacts differently to light of various orientations. The researchers found that cellulose’s intrinsic birefringence is powerful enough to be used in optical displays, such as flexible screens or electronic paper.
Hence, the team envisions that cellulose could be used as light compensation films for liquid crystal displays (LCDs) since LCDs operate by controlling the brightness of pixels using filters that allow only one orientation of light to pass through. Potentially, any smartphone, computer or television that has an LCD screen could see improved contrast, along with reduced color unevenness and light leakage, with the addition of cellulose nanofiber films.
“Cellulose nanofibers are promising light compensation materials for optoelectronics, such as flexible displays and electronic paper, since they simultaneously have good transparency, flexibility, dimensional stability and thermal conductivity. So look out for this ancient material in your future high-tech devices,” said lead author Dr. Kojiro Uetani of Osaka University.
The article can be found at: Uetani et al. (2019) Estimation of the Intrinsic Birefringence of Cellulose Using Bacterial Cellulose Nanofiber Films.
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Source: Osaka University; Photo: Osaka University.
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