Biodegradation Resistance of Cotton Fiber Doped with Interior and Exterior Silver Nanoparticles in Soil

Authors: Nam, Sunghyun; Tewolde, Haile; He, Zhongqi; Rajasekaran, Kanniah - Rajah; Cary, Jeffrey; Thyssen, Gregory; ZHANG, HAILIN - Oklahoma State University; Sickler, Christine; Islam, Md Muhaiminu

Submitted to: ACS Omega
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2024
Publication Date: 3/6/2024
Citation: Nam, S., Tewolde, H., He, Z., Rajasekaran, K., Cary, J.W., Thyssen, G.N., Zhang, H., Sickler, C.M., Islam, M. 2024. Biodegradation Resistance of Cotton Fiber Doped with Interior and Exterior Silver Nanoparticles in Soil. ACS Omega. 9(11): 13017-13027. https://doi.org/10.1021/acsomega.3c09390.
DOI: https://doi.org/10.1021/acsomega.3c09390

Interpretive Summary: Silver nanoparticles represent highly sought-after agents in the textile industry for the production of odor-inhibiting and anti-infective textiles. Various nanoparticle finishing methods, ranging from surface coatings to intercalation, have been developed. However, there is limited knowledge of the biodegradation behaviors of cotton fibers doped with silver nanoparticles on the fiber surface and throughout the fiber cross-section. In this study, we introduced both interior (18 ± 4 nm) and exterior (126 ± 17 nm) silver nanoparticles to cotton fibers with a total concentration of 11 g/kg and conducted a soil burial study. This in situ synthesis was achieved by using the non-cellulosic constituents present in raw cotton fibers and starch sizing as reducing agents, obviating the necessity for additional agents. Notably, the treated cotton fabric exhibited strong resistance to biodegradation in soil, maintaining fabric and fiber structural integrity even after 16 weeks of burial, a period during which the untreated fabric disintegrated, losing more than 30% of its weight. The diminished biodegradability observed in the treated cotton fabric was ascribed to the potent antimicrobial properties of silver nanoparticles. When tested with the GFP-expressing soil-borne fungus A. flavus, the treated cotton fabric emitted minimal green fluorescence and exhibited a 56-fold reduction in fungal growth compared to the untreated cotton fabric. As for the behavior of silver, there was an initial increase in its rate of loss over time, followed by a plateau. This nonlinear pattern suggests that the depletion of nanoparticles from the cotton fabric is influenced by their location, with interior nanoparticles proving durable against environmental exposure.

Technical Abstract: Engineering fibers with nanomaterials is an effective way to modify their properties and responses to external stimuli. In this study, we doped cotton fibers with silver nanoparticles, both on the surface (126 ± 17 nm) and throughout the fiber cross-section (18 ± 4 nm), and examined the resistance to biodegradation in soil. A reagent-free one-pot treatment of a raw cotton fabric, where non-cellulosic constituents of the raw cotton fiber and starch sizing served as reducing agents produced silver nanoparticles with a total concentration of 11 g/kg. In a soil burial degradation study spanning 16 weeks, untreated cotton underwent a sequential degradation process—fibrillation, fractionation, and merging—corresponding to the length of the soil burial period, where as the treated cotton did not exhibit significant degradation. The remarkable biodegradation resistance of the treated cotton was attributed to the antimicrobial properties of silver nanoparticles, as demonstrated through a test involving the soil-borne fungus Aspergillus flavus. The nonlinear loss behavior of silver from the treated cotton suggests that nanoparticle depletion in the soil depends on their location, whether they are present in the interior or exterior of the cotton fiber.