D. J. Evans, R. J. Denning, J. S. Church

C. E. Coombs, A. L. Woodhead, J. S. Church

J. S. Church A. L. Woodhead

The use of Fourier-transform infrared attenuated total reflectance (ATR) spectroscopy to depth profile Merino wool fibres has been investigated. The results obtained from untreated fibres are compared to those obtained from polyamide fibres. Second order derivatives were used to assist in data analysis. The use of ATR depth profiling to study the near surface chemistry of oxidation reactions is also demonstrated.

J. S. Church, A. L. Woodhead

An "at-line" Near Infrared Spectroscopy (NIRS) based method for the rapid determination of regain was develpped. An acceptable Standard Error of Prediction of the order of 0.5% regain was obtained. The method was trialled at several commercial mills. The results were found to be in very good agreement with those profuced using the CSIRO Direct Reading Regain Tester but only required a fraction of the sample and time to obtain. The data provided by the NIRS method was found to be useful for the adjusting dryer settings, assessing uniformity of sdryness and trouble shooting post-treatment gilling problems.The calibration was found to be quite robust as temperature, mean fibre diameter and chemical treatment of the sliver had little, if any, effect on tjhe accuracy of the measurements. This demonstrates the potential to develop calibrations with specific sensitivities to parameters important to wool processing and thus opens the door for the future design and production of a low cost, robust, hand-held NIRS based rapid regain determination device.

J. S. Church

J. S. Church, W. H. Leong

The use of FT-IR Photo-Acoustic (PA) and FT-Raman spectroscopies for the qualitative and quantitative determination of wool textile blends has been investigated. Methods have been developed for both techniques that involve the spectral subtraction of the individual components of the blends. The methods allow for both the identification and quantification of each blend component. The analyses can be preformed on sample masses as small as 10 mg. The sample through-put rate for the PA method can be as high as one sample per minute while analysis by the Raman method can take up to 15 minutes per sample. For the Raman analysis no sample preparation is required. As the PA result are more representative of the top layer of the sample than the bulk, some samples need to be homogenized prior to analysis. A number of intimately blended fabrics and yarns as well as some fabric blended during weaving were analyzed by both spectroscopic methods and the results compared to those obtained by the standard wet chemical method. The spectroscopic results were found to be in good agreement with those obtained by the standard method.

J. S. Church, N. W. Cant

The oxidative dehydrogenation of ethane to ethylene over three types of strontium-containing catalysts has been investigated. The catalysts are much more active and selective than for the corresponding methane coupling reaction and ethylene yields of up to 40% are possible with a 20% ethane / 10% oxygen feed. Lanthana and magnesia based catalysts are the most active but strontium carbonate/aluminosilicate catalysts are more selective. Although DRIFTS measurements of the latter show the presence of strontium silicates and aluminates in the bulk XPS indicates that the surface layers are largely SrCO₃ and that the high selectivity is related to the presence of some sodium. Carbonates also dominate at the surface of the other catalysts but the magnesia-based ones show oxides as well in conformity with DRIFTS measurements of the bulk.

E. A. Carter, J. S. Church, R. J. Denning, P. M. Fredericks

FT-Raman spectroscop has been found to be a useful tool for the study of wool. Fluorescence, which was a serious problem for conventional Raman of wool, is of minor significance with near IR excitation. Wool was studied as dry material, both stretched and unstreatched, and also in aqueous media of differing pH. The Raman spectrum reflected the bulk structure of the wool rather than its surface chemistry.