Author:      SHA YAN  2014-04-16

With the extensive use of polymers, the classification and recycling of post-consumer polymers have become an urgent problem for environmental protection. Currently, traditional polymer identification method, such as manual sorting according to resin coding system, X-ray fluorescence (XRF) spectrometry, and near-infrared (NIR) spectroscopy are time-consuming, not accurate and restricted to very few polymer identification. Laser-induced breakdown spectroscopy (LIBS) is a novel method used for sorting post-consumer polymers with some intrinsic advantages, such as high-speed, high-precision and, identification scope and no need sample preparation. However, the current identification accuracy still cannot meet the requirement for identifying effectively the vast majority of polymers used in our daily lives.

To address these problems, a new approach to adjusting spectral weightings (ASW) for polymer identification was developed by Yang Yu and Lianbo Guo et al. under the directions of Prof. Xiaoyan Zeng and Prof. Xiangyou Li. This approach has been achieved through increasing the intensities of specific characteristic spectral lines which are important to polymer identification but difficult to be excited. Using the ASW method, the identification accuracies of all 11 polymers were increased to nearly 100%, while the accuracies of PE, PU, PP and PC were only 98%, 74%, 90% and 98%, respectively, without using the ASW method.

This work has been published on the journal Optics Express of OSA (Vol. 22 Issue 4, pp.3895-3901, 2014) and is financially supported by National Science Foundation of China (No. 51128501)and the National Instrument Development Specific Project of China (No. 2011YQ160017).