Abstract

Diffuse reflectance spectroscopy in the near-infrared (NIR) region (1100-2400 nm) was used to characterize the morphology of fibrous and bulk poly(ethylene terephthalate) (PET). The method of Partial Least-Squares (PLS) was used to correlate NIR spectra of PET yarns with percent crystallinity. Standard error of prediction values for percent crystallinity in PET yarns are in the range of 2-3.5% crystallinity, and depended on the specific NIR spectral region used for analysis. Principal Components Analysis (PCA) was used to study the differences in NIR spectra of bulk PET samples that were crystallized at different temperatures. It was observed that NIR spectroscopy can detect changes in both intermolecular and intramolecular interactions in PET. The observed effect of crystallization temperature on the morphology of bulk PET is very similar to effects observed in earlier IR and thermal analyses. In addition, detection of moisture in bulk PET is demonstrated.

Effects of prestrain applied to poly(ethylene terephthalate) substrate on microstructures and morphologies of porous TiO₂ film and optical scattering behaviors of light

Tse-Chang Li, Cheng-Fang Ho, and Jen-Fin Lin
Appl. Opt. 54(4) 816-827 (2015)

Rapid determination of the main components of corn based on near-infrared spectroscopy and a BiPLS-PCA-ELM model

Lili Xu, Jinming Liu, Chunqi Wang, Zhijiang Li, and Dongjie Zhang
Appl. Opt. 62(11) 2756-2765 (2023)

Cost-effective way to improve the optical properties of poly(methyl methacrylate)/poly(ethylene terephthalate) light scattering materials: drop coalescence

Xiao Liu, Ziru Zhao, Ying Xiong, Ping Yi, and Shaoyun Guo
Appl. Opt. 57(9) 2107-2114 (2018)

Optical diffuse reflectance accessory for measurements of skin tissue by near-infrared spectroscopy

R. Marbach and H. M. Heise
Appl. Opt. 34(4) 610-621 (1995)

Nondestructive determination of SSC in an apple by using a portable near-infrared spectroscopy system

Yizhe Zhang, Jipeng Huang, Qiulei Zhang, Jinwei Liu, Yanli Meng, and Yan Yu
Appl. Opt. 61(12) 3419-3428 (2022)