Location: Cotton Chemistry and Utilization Research
2017 Annual Report
Accomplishments
1. Additive color blending to increase apparent fabric whiteness in a nonwoven textile application. ARS scientists in New Orleans, Louisiana, collaborated with a major cotton staple fiber stakeholder to expand the greige cotton fiber in nonowoven hygiene applications. This achievement is the direct result of ARS scientists developing an optimized additive color and fiber blend ratio with greige cotton using this intimate fiber blending technique that dramatically increases the whiteness of the greige fibers which are typically yellowish in color. The optimized blending can be tailored to specific greige fibers that can vary slightly in natural color. The research has resulted in an annual increase in greige cotton fiber use in nonwovens of approximately 2,000 bales. The consumption of greige cotton in this application is predicted to increase to approximately 10,000 bales in the next year.
2. The mechanisms of the thermal stability of raw cotton were characterized and verified. This verification was achieved by combining kinetic and analytical studies. According to the results, the low-temperature dehydration reactions catalyzed by inorganic salts substantially suppressed the “unzipping” depolymerization of cellulose at high temperatures and consequently reduced the production of highly volatile levoglucosan, a major constituent of flammable tar. The levoglucosan detected in raw cotton using pyrolysis gas chromatography mass spectrometry (Py-GC/MS) was two orders of magnitude less abundant than in scoured cotton. Such modified thermal reactions were supported by the chemical and structural changes in the solid substrate as well as the types of gaseous products in the entire range of pyrolysis temperature. These comprehensive analyses, conducted by ARS scientists at New Orleans, Louisiana, allowed a more complete picture of the thermal processes of raw cotton for its practical utilization as well as for its aging and deterioration at elevated temperatures.
3. The silver nanoparticle-cotton system previously developed by research scientists in New Orleans, Louisiana, showed stable and durable antimicrobial properties in laundering tests. Simply copying the nanotechnology developed in other fields, i.e., buying nanoparticles, nanotubes, or nanocrystals and applying them onto textiles, have raised environmental, health, and performance durability issues. A great deal of originality is required to develop safe and durable nanoengineered cotton. The uniform dispersion of silver nanoparticles inside the fiber was not influenced by fifty cycles of laundering, and the laundered nanocomposite fibers retained 92% of the silver nanoparticles in concentration. More importantly, powerful antibacterial activity against Escherichia coli and Staphylococcus aureus maintained after laundering. This nanocomposite fiber will continuously deliver antibacterial activity wash after wash, making it potential for antibacterial washable wipes.
4. Inspired by a previous study showing that the superior thermal resistance of brown cotton fibers was linked to naturally occurring tannins and inorganic salts, the improved flame resistance of tannic acid was achieved by the addition of sodium hydroxide. Tannins concentrated in the barks of trees are naturally fire resistant, but the use of tannins for cotton has been limited to a dyeing fixative. According to limiting oxygen index (LOI) measurement, tannic acid alone was not effective as a flame-retardant for cotton, but the addition of low concentrations of sodium hydroxide increased the LOI up to 30%. This remarkable synergistic effect of sodium ions was explained by the formation of intumescent char, in which fibrous char was embedded, more effectively hinders the transfers of heat and combustible gases. The cotton nonwoven fabrics coated with tannic acid along with sodium ions are expected by ARS scientis at New Orleans, Louisiana, to serve as a fire barrier in mattresses and furniture applications.
Review Publications
Nam, S., Condon, B.D., Liu, Y., He, Q. 2017. Natural resistance of raw cotton fiber to heat evidenced by the suppressed depolymerization of cellulose. Polymer Degradation and Stability. 138:133-141.
Hinchliffe, D.J., Condon, B.D., Thyssen, G.N., Naoumkina, M.A., Madison, C.A., Reynolds, M.L., Delhom, C.D., Fang, D.D., Li, P., McCarty Jr, J.C. 2016. The GhTT2_A07 gene is linked to the brown colour and natural flame retardancy phenotypes of Lc1 cotton (Gossypium hirsutum L.) fibres. Journal of Experimental Botany. 67(18):5461-5471.
Santiago Cintron, M., Montalvo, J.G., Von Hoven, T.M., Rodgers, J.E., Hinchliffe, D.J., Madison, C.A., Thyssen, G.N., Zeng, L. 2016. Infrared imaging of cotton fiber bundles using a focal plane array detector and a single reflectance accessory. FIBERS. 4(27):1-11. https://doi.org/10.3390/fib4040027.
Mattison, C.P., Rai, R., Settlage, R.E., Hinchliffe, D.J., Madison, C.A., Bland, J.M., Brashear, S.S., Graham, C.J., Tarver, M.R., Florane, C.B., Bechtel, P.J. 2017. RNA-seq analysis of developing pecan (Carya illinoinensis) embryos reveals parallel expression patterns among allergen and lipid metabolism genes. Journal of Agricultural and Food Chemistry. 65:1443-1455. doi:10.1021/acs.jafc.6b04199.
Edwards, J.V., Prevost, N.T., Nam, S., Hinchliffe, D.J., Condon, B.D., Yager, D. 2017. Low-level hydrogen peroxide generation by unbleached cotton nonwovens: implications for wound healing applications. Journal of Functional Biomaterials. 8(1):1-13. doi:10.3390/jfb8010009.
Naoumkina, M.A., Hinchliffe, D.J., Fang, D.D., Florane, C.B., Thyssen, G.N. 2017. Role of xyloglucan in cotton (Gossypium hirsutum L.) fiber elongation of the short fiber mutant Ligon-lintless-2 (Li2). Gene. 626:227-233.
Nam, S., Condon, B.D., Delhom, C.D., Fontenot, K.R. 2016. Silver-cotton nanocomposites: nano-design of microfibrillar structure causes morphological changes and increased tenacity. Scientific Reports. 6(37320):1-10. https://doi.org/10.1038/srep37320.
