Cotton Chemistry and Utilization Research

Robert Lee, LA, United States

Cotton Chemistry and Utilization Research

Robert Lee, LA, United States
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News Article | July 7, 2017
Site: phys.org

Cross-section of a cotton fiber with silver nanoparticles (black dots) trapped inside it. Credit: Sunghyun Nam Silver has been used as an antimicrobial agent for more than 100 years. Today, silver in the form of nanoparticles is incorporated in such products as plastic food containers, medical materials, and clothing. In textiles, however, preventing the nanoparticles' antimicrobial properties from washing away has always been a problem. But not anymore. Scientists at the Agricultural Research Service's (ARS) Southern Regional Research Center (SRRC) in New Orleans, Louisiana, have developed a method to trap silver nanoparticles inside cotton fibers, where they remain wash after wash. The amount of silver nanoparticles required to kill bacteria is extremely small, which makes them efficient and cost effective to use. Moreover, the new method, developed by ARS materials engineer Sunghyun Nam and her colleagues, is inexpensive and eco-friendly. Typically, silver nanoparticles—particles that are 1 to 100 nanometers in diameter—are grown in a bulk chemical solution. In the new technology, the silver nanoparticles are produced within the cotton fibers, making their application more effective and affordable. Silver nanoparticles slowly release silver ions that can kill more than 600 kinds of bacteria, including E. coli, says Nam, who works in the SRRC Cotton Chemistry and Utilization Research Unit. The problem has been that currently available methods could only apply silver nanoparticles to the surface of fibers, where they would wash away. "Our new process grows and traps the silver nanoparticles inside cotton fibers," Nam says. "They release their silver ions very slowly, killing bacteria for a long time. Our process also allows us to produce extremely small nanoparticles, about 12 nanometers in diameter." One nanometer is a billionth of a meter. For example, a sheet of paper is about 100,000 nanometers thick. The extremely small size of the silver nanoparticles results in a larger surface area, which increases the number of silver ions coming into contact with bacteria. In a recent study published in Scientific Reports, Nam and ARS postdoctoral research chemist Krystal Fontenot showed that even after 50 home laundering cycles, their silver-cotton nanocomposite fiber retained about 93 percent antimicrobial silver nanoparticles and continued to kill harmful bacteria. The new technology also strengthened the cotton fibers. This technology has many possible applications. For example, fabrics or bandages made with these new nanoparticle-containing fibers may be effective in wound or burn treatments, says Brian Condon, the unit's research leader. "The nanoparticles may be used in durable or nonwash fabrics—disposable undergarments, shoe liners, upholstery, and bedding—to protect the users from infection," he adds. For now, the researchers plan to produce a nonwoven fabric cloth for wiping floors to evaluate its antimicrobial activities. "We want to find out how many bacteria are killed on the floor initially and how many are killed after repeated washing," Nam says. Explore further: New treatments could reduce odors in cotton fabric More information: Sunghyun Nam et al. Silver-cotton nanocomposites: Nano-design of microfibrillar structure causes morphological changes and increased tenacity, Scientific Reports (2016). DOI: 10.1038/srep37320


Nguyen M.M.,Cotton Chemistry and Utilization Research | Al-Abdul-Wahid M.S.,Miami University Ohio | Fontenot K.R.,Cotton Chemistry and Utilization Research | Graves E.E.,Cotton Chemistry and Utilization Research | And 4 more authors.
Molecules | Year: 2015

Countless hours of research and studies on triazine, phosphonate, and their combination have provided insightful information into their flame retardant properties on polymeric systems. However, a limited number of studies shed light on the mechanism of flame retardancy of their combination on cotton fabrics. The purpose of this research is to gain an understanding of the thermal degradation process of two triazine-phosphonate derivatives on cotton fabric. The investigation included the preparation of diethyl 4,6-dichloro-1,3,5-triazin-2-ylphosphonate (TPN1) and dimethyl (4,6-dichloro-1,3,5-triazin-2-yloxy) methyl phosphonate (TPN3), their application on fabric materials, and the studies of their thermal degradation mechanism. The studies examined chemical components in both solid and gas phases by using attenuated total reflection infrared (ATR-IR) spectroscopy, thermogravimetric analysis coupled with Fourier transform infrared (TGA-FTIR) spectroscopy, and 31P solid state nuclear magnetic resonance ( (13P solid state NMR), in addition to the computational studies of bond dissociation energy (BDE). Despite a few differences in their decomposition, TPN1 and TPN3 produce one common major product that is believed to help reduce the flammability of the fabric. © 2015 by the authors.


Fontenot K.R.,Cotton Chemistry and Utilization Research | Nguyen M.M.,Cotton Chemistry and Utilization Research | Al-Abdul-Wahid M.S.,Miami University Ohio | Easson M.W.,Cotton Chemistry and Utilization Research | And 3 more authors.
Polymer Degradation and Stability | Year: 2015

Phosphazene derivatives have been recognized as promising flame retardants for numerous synthetic polymeric systems. However, limited studies are available for phosphazene derivatives on natural polymeric systems such as cotton fabric. The flammability and thermal stability of fabric treated with a phosphazene derivative 1,1,3,3-dihydroxybiphenyl-5,5-diaminoethanephosphazene (dBEP) indicated that only 9 wt% add-on of dBEP was required to achieve promising flame retardant properties on cotton fabric. To understand the mode of action of dBEP, the thermal degradation pathways of the control and cotton fabric treated with dBEP were investigated. Thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA-FTIR) was used to follow the evolved gases produced by the control and treated fabrics during thermal degradation. Two techniques, attenuated total reflectance infrared spectroscopy (ATR-IR) and solid-state nuclear magnetic resonance (NMR) were employed to examine the degraded residues of the unburned fabrics, burned fabrics, and dBEP. The results show that dBEP undergoes decomposition to produce phosphoric acid and polymerization to form phospham-like derivative that are known to retard fire. © Published by Elsevier Ltd.


PubMed | Miami University Ohio and Cotton Chemistry and Utilization Research
Type: Journal Article | Journal: Molecules (Basel, Switzerland) | Year: 2015

Countless hours of research and studies on triazine, phosphonate, and their combination have provided insightful information into their flame retardant properties on polymeric systems. However, a limited number of studies shed light on the mechanism of flame retardancy of their combination on cotton fabrics. The purpose of this research is to gain an understanding of the thermal degradation process of two triazine-phosphonate derivatives on cotton fabric. The investigation included the preparation of diethyl 4,6-dichloro-1,3,5-triazin-2-ylphosphonate (TPN1) and dimethyl (4,6-dichloro-1,3,5-triazin-2-yloxy) methyl phosphonate (TPN3), their application on fabric materials, and the studies of their thermal degradation mechanism. The studies examined chemical components in both solid and gas phases by using attenuated total reflection infrared (ATR-IR) spectroscopy, thermogravimetric analysis coupled with Fourier transform infrared (TGA-FTIR) spectroscopy, and 31P solid state nuclear magnetic resonance (31P solid state NMR), in addition to the computational studies of bond dissociation energy (BDE). Despite a few differences in their decomposition, TPN1 and TPN3 produce one common major product that is believed to help reduce the flammability of the fabric.

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