X-Ray Diffractometric Measurement of Microcrystallite Size, Unit Cell Dimensions, and Crystallinity: Application to Cellulosic Marine Textiles

Abstract

Procedures were developed to enable standard x-ray diffractometric equipment to be used to study and compare textile fiber crystallographic characteristics. The approach was based on fitting diffractometric data to the Gaussian distribution by weighted regression analysis, which also supported an assessment of error propagation. Crystallite dimensions were obtained through the Scherrer method using analytically derived spectral line breadths. Percent crystalline component was determined by summing background-corrected amorphous and crystalline components of the spectra. A dif fractometric analysis was made of samples of rare textiles recovered from a 133-year old shipwreck, as well as modem fabrics submerged for three months at the same deep ocean site. The microcrystallite size of the historic textile materials increased, while the percent crystalline component decreased and unit cell dimensions remained con stant. The crystallite sizes of modern linen immersed for three months with iron, copper, or alone did not increase, while the percent crystalline component decreased and the unit cell dimensions remained constant.