While a large-scale soil amendment of biochars continues to receive interest for enhancing crop yields and to remediate contaminated sites, systematic study is lacking in how biochar properties translate into purported functions such as heavy metal sequestration. In this study, cottonseed hulls were pyrolyzed at five temperatures (200, 350, 500, 650, and 800 °C) and characterized for the yield, moisture, ash, volatile matter, and fixed carbon contents, elemental composition (CHNSO), BET surface area, pH, pHpzc, and by ATR-FTIR. The characterization results were compared with the literature values for additional source materials: grass, wood, pine needle, and broiler litter-derived biochars with and without post-treatments. At respective pyrolysis temperatures, cottonseed hull chars had ash content in between grass and wood chars, and significantly lower BET surface area in comparison to other plant source materials considered. The N:C ratio reached a maximum between 300 and 400 °C for all biomass sources considered, while the following trend in N:C ratio was maintained at each pyrolysis temperature: wood≪cottonseed hull≈grass≈pine needle≪broiler litter. To examine how biochar properties translate into its function as a heavy metal (NiII, CuII, PbII, and CdII) sorbent, a soil amendment study was conducted for acidic sandy loam Norfolk soil previously shown to have low heavy metal retention capacity. The results suggest that the properties attributable to the surface functional groups of biochars (volatile matter and oxygen contents and pHpzc) control the heavy metal sequestration ability in Norfolk soil, and biochar selection for soil amendment must be made case-by-case based on the biochar characteristics, soil property, and the target function.

Two of the important cotton fiber quality and processing parameters are fiber maturity and fineness. Fiber maturity is the degree of development of the fiber’s secondary wall, and fiber fineness is a measure of the fiber’s linear density and can be expressed as mass per unit length. A well-known method for fiber maturity and fineness is a cross-section image analysis and microscopy measurement. In general, typical cross-section image analysis and microscopy methods for fiber maturity and fineness can be slow and tedious to perform. Much interest has been shown in improved and rapid routine measurements of fiber maturity and fineness in the laboratory. The Cottonscope® is a new small footprint instrument for measuring fiber maturity and fineness, consisting of a longitudinal measurement of weighted fiber snippets in water using polarized light microscopy and image analysis. A program was implemented to assess the potential and capabilities of the Cottonscope to measure cotton lint maturity and fineness and to determine the major operational impacts on the Cottonscope results. The measurement was fast and easy to perform. The major operational impact on the Cottonscope results was environmental conditions (room temperature and relative humidity), and its impact was a concern for fineness only. Very good method agreement was observed between the Cottonscope and image analysis and microscopy method for maturity and fineness, with moderate coefficients of determination, R2s, and low residuals. Recommended operational protocols for routine Cottonscope measurements were developed.

A novel flame retardant diethyl 4-methylpiperazin-1-ylphosphoramidate (CN-3) containing phosphorous and nitrogen was prepared. Its chemical structure was confirmed by nuclear magnetic resonance ( 1 H-, 13 C-, and 31 P-NMR), Fourier transform infrared spectroscopy, and elemental analysis. Print cloth and twill fabrics were treated with CN-3 to achieve different levels of add-on (7-22 wt% add-ons for print cloth and 3-18 wt% add-ons for twill). Thermogravimetric analysis, vertical flame test, and limiting oxygen index (LOI) were performed on the treated cotton fabrics and showed promising results. When the treated print cloth and twill fabric samples were tested using the vertical flame test (ASTM D6413-08), we observed that the ignited fabrics self-extinguished and left behind a streak of char. Treated higher add-ons fabrics were neither consumed by flame nor produced glowing ambers upon selfextinguishing. LOI (ASTM 2863-09) was used to determine the effectiveness of the flame retardant on the treated fabrics. LOI values increased from 18 vol% oxygen in nitrogen for untreated print cloth and twill fabrics to maximum of 28 and 31 wt% for the highest add-ons of print cloth and twill, respectively. The results from cotton fabrics treated with CN-3 demonstrated a higher LOI value as well as a higher char yield because of the effectiveness of phosphorus and nitrogen as a flame retardant for cotton fabrics. Furthermore, FT-IR and SEM were used to characterize the chemical structure on the treated fabrics as well as the surface morphology of char areas of treated and untreated fabrics. Published 2012. This article is a US Government work and is in the public domain in the USA.

The high demand for cotton production worldwide has demonstrated the need for standardized classification of foreign matter present with cotton. Cotton trash can become comingled with fiber during the ginning and harvesting processes. The conventional instrumental method used to determine the amount of cotton trash present with cotton fiber, the high volume instrument (HVI), lacks specificity in the identification of individual trash components (leaf, etc.). Fourier transform near-infrared (FT-NIR) spectroscopy was investigated to distinguish the individual types of cotton trash from the fiber. In this study, the concept of monitoring differences in spectral bands of cotton and cotton trash by FT-NIR spectroscopy was demonstrated and provided a ‘proof of concept.’ A spectral library based on NIR spectral data and pre-processing methods was developed using cotton and cotton trash samples (hull, leaf, seed coat, and stem) yielding over 97% identification accuracy of cotton trash components in the prediction set.