Location: Cotton Chemistry and Utilization Research
2021 Annual Report
Objectives
1. Enable, from a technological standpoint, new commercial processes for the production of cotton-based products with enhanced flame retardant and moisture control properties.
2. Enable new commercial processes for manufacturing cotton-based body-contacting materials for use in biomedical, biosensor and hygienic applications.
3. Enable new commercial processes involving supercritical fluids, microwaves, ultrasound, or ionic liquids for the production of cotton-based products.
Approach
The U.S. cotton industry continues to face supply and demand concerns. Since cotton is used in manufactured products, the industry has been challenged by the downsizing of manufacturing facilities that traditionally provide a major underpinning to domestic cotton consumption. Thus, with the goal of giving U.S. cotton utilization a competitive edge, research emphasis will be placed in cotton fiber science and product development where consumer and industrial needs are unmet and show promise. Some of the areas of consumer need for cotton products and process potential are flame retardant durable goods and apparel, and nonwoven body-contacting materials including improved wound dressings and hygienic/incontinence nonwovens, advanced nonmaterial’s. Enabling technologies that will enhance the likelihood of success and keep pace with industrial innovations include enzymatic bioprocessing, microwave-assisted synthesis and nanotechnology. To accomplish this, a three part approach will be taken: 1) Synthesizing FR compounds will include cross-linking small molecules, binding agents and reactive electrophilic functionalities. The treated fabrics will be tested using standard FR tests and the pyrolysis mechanism and gas emissions will be assessed to develop robust FR treatments for potential commercialization. 2) A broad set of characteristics implies a varied approach to design and preparation of cotton-based prototypes as body-contacting materials. Hemostatic and chronic wound dressings, incontinence absorbents, associated top sheet(s), and contiguous acquisition and absorbent layers of these materials constitute one general group, and nanocellulosic protease biosensors still another. Structure activity relations in turn rely on structural analysis including electrokinetic parameters (fiber surface chemistry), fluorescence, colorimetry, infrared spectroscopy, x-ray crystallography, and computational chemistry to list some of the primary and pivotal technologies to enable structure activity relations. 3) Four technological processes (supercritical carbon dioxide fluid, microwave radiation, ultrasonic energy, and ionic liquids) will be collectively explored as avenues of research, leading to the development of value-added products derived from cotton cellulosic sources. This multifaceted technological approach will ensure that leads are generated in the form of novel synthetic flame retardant (FR) compounds, nonmaterial’s, extruded bioorganic fibers, moisture control fabrics, ethanolic mbiofuel, and bio-finished cotton fabrics.
Progress Report
This is the final report for project 6054-41430-008-00D, a bridging study. Moreover, it is a summary of progress made during the CRIS project bridging period from May 5, 2020 to November 15, 2020 by ARS researchers in New Orleans, Louisiana. Progress was made by ARS researchers in New Orleans, Louisiana on all three objectives, all of which fall under National Program 306, Component 2, Quality and Utilization of Agricultural Products, Non-Food. Progress on this project focuses on Problem 2A to increase or protect the market demand for (or increase the value of) existing United States produced non-food bio-based products derived from agricultural products and byproducts. ARS researchers in New Orleans, Louisiana, have developed new products, applications, and processes for expansion of domestic cotton in the areas of: (1) moisture control properties and hygienic and cotton fabric hand applications; (2) conversion of biomass to nanocrystals; (3) flame retardant cotton; (4) utilization of enabling technologies for improved flame retardant cotton; (5) Sensors that utilize a form of cellulose with high surface area to detect disease biomarkers; (6) cotton-based blood antibacterial and antiviral fabrics for wound dressings and face masks; (7) and hemorrhage control dressings with improved clotting properties.
Cotton-Based Sensor Assembly and Design to Detect Sars Covid2 in Support of Objective 1 and 3: Combating the virus that has caused the COVID-19 pandemic has been a challenge for healthcare professionals and the public at-large. ARS researchers in New Orleans, Louisiana have investigated how cotton is applicable to both the detection and prevention of virus infection. ARS researchers in New Orleans, Louisiana work on detecting and preventing the spread of the virus first focused on how the virus enters human cells. The virus enters human cells by binding to their surface. Design of sensors that detect the virus use information about the virus process of cell entry. ARS researchers in New Orleans, Louisiana used this type of conceptual approach to help design agents (peptides), which were prepared and studied for their ability to adhere to components (proteins) on the surface of the virus. The ‘virus-binding peptides’ were then prepared by ARS researchers in New Orleans, Louisiana , and their structure studied. Models of the peptides and the shape they adopt were stored in ARS New Orleans, Louisiana endnote and power point files. The peptides are being employed to study their use to detect and inhibit Sars-Covid19 and may eventually be used in biosensors attached to cotton derivatives and to combat virus infection.
Construction and Testing of Cotton-Based Face Mask with Antiviral Activity in Support of Objective 1 and 2: ARS researchers in New Orleans, Louisiana suggest the design and efficacy of facemask textiles is receiving increased attention due to the importance of fabrics to combat human infection. This is apparent from their use during the Covid19 pandemic. Moreover, evaluation of new textile designs in cloth facemasks for safe, sustainable, and economical properties is important to the current healthcare crisis brought on by Sars Covid2. A study conducted by ARS researchers in New Orleans, Louisiana revealed that a cotton-based fabric formulated with ascorbic acid was active against gram negative and positive bacteria and exhibited 99.999% antiviral activity against a challenge virus like that found in polio. Antiviral testing by ARS researchers in New Orleans, Louisiana against the same virus showed that the ascorbic acid treated fabric reduced viral load of the same virus by 99.99 percent in one hour compared with the control at time zero. The fabric activity was shown to be due to generation of hydrogen peroxide. The fabric was also tested by ARS researchers in New Orleans, Louisiana in a similar coronavirus assay employing Human Coronavirus. It showed at least 90% reduction with the ascorbic acid-treated fabric and none in the other samples which included an N-95 mask sample and a cotton control. Stakeholders have actively sought to bring this to market due to the current need for improved facemasks.
Isolation of Lignin from Cotton Ginning By-Products in Support of Objective 3: The processing of field cotton produces a high volume of cotton waste. ARS Researchers in New Orleans, Louisiana are looking for high value uses of the cotton waste. The specific types of cotton gin waste are termed gin motes and cotton gin trash. Lignin, which is a naturally occurring rigid polymer found in most plants, is a part of the cotton gin waste. ARS researchers in New Orleans, Louisiana used gin motes and gin trash to prepare a special type of cellulose fiber that contains lignin. The special material is called lignin-containing nanofibers (LCNFs). The amount of lignin measured in LCNFs varied from 3% to 18%. The different amounts of lignin gave the LCNFs different properties which are useful in high-value products. LCNFs from gin motes were larger in size, more organized, heat tolerant and tended to group together in water. Those from gin trash were less resistant to heat, less organized and shorter in size. Because of this, these LCNFs did not bunch together. This finding is important when mixing LCNFs with plastics, when using LCNFs as thickening agents, or when using LCNFs to strengthen materials. These results suggest potential use in bio-based plastics, packaging, and tissue engineering products.
Application of Lignin-Containing Cellulose as a Protective Sealant in Forest Pruning: During growing, trees are routinely pruned by ARS researchers in New Orleans, Louisiana to allow the tree to grow properly. However, pruning a tree can leave it open for disease and pests. ARS researchers in New Orleans, Louisiana prepared a lignin-containing cellulose material to act as a sealant for pruned trees. ARS researchers in New Orleans, Louisiana in a collaboration with the National Arboretum in Washington D.C., four species of trees were selectively pruned. Half the trees were left untreated and half the trees were treated with lignin-containing cellulose as a protective sealant. Trees were observed by ARS researchers in New Orleans, Louisiana for several weeks and notes were recorded describing the condition of the untreated and treated trees. This project is currently ongoing, and any findings will be reported later.
Cotton-Based Nanocellulose from Cotton By-Products in Support of Objective 3: Cellulose nanocrystals (CNCs) are small, resistant to applied force, and well-organized parts of cotton fibers. They are prepared using harsh conditions and strong acids. This produces a lot of excess waste. To reduce waste, CNCs were prepared by ARS researchers in New Orleans, Louisiana from cotton gin motes using dilute acids and an ionic liquid. The ionic liquid can be recycled, which is safer for the environment. Using this method, the CNCs were larger in size, which is important for preparing gas absorbents and emulsions. They were also more tolerant to high heat. Future work by ARS researchers in New Orleans, Louisiana will look at other ionic liquids to see what effect they have on CNCs properties.
Flame Retardant Cotton In Support of Objective 2: ARS researchers in New Orleans, Louisiana believe new approaches to prepare flame retardant cotton fabrics are needed to develop low-cost and effective flame-retardant cotton. ARS researchers in New Orleans, Louisiana used microwave technology to modify cotton fabrics with minimum amounts of solvent. The small amount of solvent used is an advance over current industrial processes to make flame retardant cotton. The cotton fabrics designed by ARS researchers in New Orleans, Louisiana were environmentally friendly. Additionally, ARS researchers in New Orleans, Louisiana developed an efficient method for the chemical treatments of a series of fabrics. The treatment yields an effective flame-retardant fabric, resulting in the addition of more of the chemical to the fabric. The treatments are also low-cost and can be applied by ARS researchers in New Orleans, Louisiana during large-scale production of cotton fabrics.
Microencapsulation in Support of Objective 2: Microencapsulation is a rapidly growing technology used commercially for protection against microbes, mosquitoes, and heat. The technology is adaptable for cotton textiles. Microcapsules are prepared by depositing a thin polymeric coating on small solid particles or liquid droplets. Cotton fabrics treated with microcapsules will be studied by ARS researchers in New Orleans, Louisiana for their slow time-release. ARS researchers in New Orleans, Louisiana have preliminary results that validate the design of the microcapsule-treated fabrics using standard test methods.
Accomplishments
1. Development of antiviral cotton nonwovens. ARS researchers in New Orleans, Louisiana, suggests combating the spread of virus infection with improved facemasks is a high priority for public health. A study by ARS researchers at New Orleans, Louisiana, in collaboration with a medical trauma wound dressing company, revealed that a jointly developed cotton nonwoven product exhibited 99.99 percent antiviral activity (challenge virus similar to polio virus) after three hours of contact with the fabric. The nonwoven was then tested and found to be effective against coronavirus at a minimum of 90 percent. Notably the test was only effective at 90 percent due to host cell modifications that occurred in the assay. The nonwoven fabrics were incorporated into cotton cloth facemasks and show promise in being adopted in the marketplace as a safe effective facemask to combat virus infection.
Review Publications
Jordan, J.H., Easson, M.W., Condon, B.D. 2020. Cellulose hydrolysis using ionic liquids and inorganic acids under dilute conditions: morphological comparison of nanocellulose. RSC Advances. 10(65):39413-39424. https://doi.org/10.1039/d0ra05976e.
Chang, S., Condon, B., Nam, S. 2020. Development of flame-resistant cotton fabrics with casein using pad-dry-cure and supercritical fluids methods. International Journal of Materials Science and Applications. 9(4):53-61. https://doi.org/10.11648/j.ijmsa.20200904.11.
Jordan, J.H., Easson, M.W., Thompson, S., Wu, Q., Condon, B.D. 2021. Lignin-containing cellulose nanofibers with gradient lignin content obtained from cotton gin motes and cotton gin trash. Cellulose. 28(2):757-773. https://doi.org/10.1007/s10570-020-03549-0.
