Detailed positron annihilation lifetime spectroscopic investigation of atrazine imprinted polymers grafted onto PE/PP non‐woven fabrics

Abstract

This study presents the preparation of molecularly imprinted matrices by using radiation-induced grafting technique onto polyethylene/polypropylene (PE/PP) non-woven fabrics. Atrazine imprinted polymers were grafted onto PE/PP non-woven fabrics through the use of methacrylic acid (MAA) and ethylene glycol dimethylacrylate (EGDMA) as the functional monomer and crosslinking agent, respectively. Grafted MIPs were characterized by attenuated total reflectance Fourier transform infra-red spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), elemental analysis, scanning electron microscopy (SEM), and positron annihilation lifetime spectroscopy (PALS). The average diameter of free volume holes was determined as 0.612 nm which correlates very well with the size of template molecule atrazine, 0.512 nm. Binding behaviors were investigated against various factors, such as concentration of template molecule, pH, and contact time. Furthermore, the specific selectivity of grafted MIP on non-woven fabric was studied by using other common triazine compounds, such as simazine and metribuzine which show structural similarities to atrazine. The specific binding values for atrazine, simazine, and metribuzine were determined as 40%, 2.5%, and 1.5%, respectively.

Synthesis and characterization of tetracycline‐imprinted membranes: A detailed positron annihilation lifetime spectroscopy investigation

“…The presence of the template molecule causes the formation of a more porous structure with low size distribution. 13,14,18 It is possible to say that the density of the aggregate pores was quite similar for MIM and NIM due to the value of I 4 obtained as 6.8% and 7.6%, respectively.…”

“…The presence of a templating molecule during the synthesis process causes the formation of the pores with higher radii. [11][12][13][14] The diameter of the free-volume holes of MIM and NIM was determined as 1.300 ± 0.001 and 0.994 ± 0.002 nm, respectively. While the diameter of the free-volume holes in the MIM shows a good correlation to the molecular size of TC (1.26 nm), 31 the size of the free-volume holes in NIM was determined smaller than that value.…”

“…9,10 To investigate the effect of the template on the size and size distribution of free-volume holes in MIP, PALS has been used several times. [11][12][13][14] The effect of the chain length of cross-linker on the size of the binding sites was investigated for glucose-imprinted membranes. 11 The effect on the size and density of the free-volume holes of the room temperature ionic liquids used as porogen in the synthesis process of propranolol-imprinted polymers prepared by bulk polymerization was also investigated by employing PALS.…”

“…13 The change of the size and the density of the cavities due to the radiation-induced crosslinking of modified ultra-high molecular weight polyethylene (UHMWPE) for preparing ion-imprinted polymers were investigated by using PALS in another work. 14 In this study, tetracycline-imprinted membranes were prepared by utilizing radiation-induced polymerization. While the detailed spectroscopic and microscopic characterization of the membranes was carried out by FTIR, XPS, SEM and AFM, the investigation of the effect of the presence of template molecule on the size and size distribution of free-volume holes was conducted by PALS experiments.…”

“…While the detailed spectroscopic and microscopic characterization of the membranes was carried out by FTIR, XPS, SEM and AFM, the investigation of the effect of the presence of template molecule on the size and size distribution of free-volume holes was conducted by PALS experiments. The detailed analysis of the PAL spectra was carried out by MELT 14,15 and LTv9. 16 Besides, the binding behaviour of the membranes was examined by employing adsorption isotherms: Langmuir, bi-Langmuir and Freundlich models.…”