To create the all-natural straws, a delignified wood slice was cut into strips measuring 3×15 cm and then soaked in a chitosan solution. The chitosan slowly permeated the microporous structure of the wood through a series of degassing cycles conducted at 100 Pa, each lasting 3 minutes. After the infusion process, the chitosan-impregnated wood strips were wrapped around stainless-steel rods with a diameter of 5.5 mm and allowed to air-dry at room temperature. A “water-morphing technique” was also applied to create an accordion-like bendable joint.
The resulting straws exhibited the necessary flexural, compressive, and tensile strengths, as well as stability in both water and beverages.
The findings were published recently in Advanced Sustainable Systems.