Synthesis, Fabrication, and Characterization of Functionalized Polydiacetylene Containing Cellulose Nanofibrous Composites for Colorimetric Sensing of Organophosphate Compounds

Abstract

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.

Low-temperature Irreversible Thermochromic Indicator Based on Functional Polydiacetylene for Food Storage Applications

“…It was observed from the 1 H NMR spectra of PC that the peak at 0.81 ppm belongs to the methyl (-CH3) group, and the multiple peaks between 1.23-1.82 ppm were related to the methylene group (-CH2-) of the hydrocarbon chain. [38] The peak at 2.17 and 2.24 ppm corresponds to the methylene group adjacent to the alkyne (-C≡) group and carboxylic group respectively. [38] In the case of PCE, following the functionalization of PC with EGME, three additional peaks appeared at 3.49, 3.35, and 4.23 ppm, which were assigned to methylene groups adjacent to the oxygen of the carboxylic and methoxy groups, respectively.…”

“…[38] The peak at 2.17 and 2.24 ppm corresponds to the methylene group adjacent to the alkyne (-C≡) group and carboxylic group respectively. [38] In the case of PCE, following the functionalization of PC with EGME, three additional peaks appeared at 3.49, 3.35, and 4.23 ppm, which were assigned to methylene groups adjacent to the oxygen of the carboxylic and methoxy groups, respectively. Conversely, in PCD, as the number of ethyleneoxy units increased, peaks appeared at 4.24, 3.56, and 4.18 ppm, corresponding to methylene and methoxy groups, respectively.…”

Polydiacetylene-based sensors for food applications

“…Alam et al used an electrospinning technique to fabricate a PDA/cellulose composite fiber capable of detecting organophosphate pesticides. 55 The PDA head groups were aldehyde modified to form a PDA ester (PCDA-HBA). The authors demonstrated the chemical recognition of diisopropyl fluorophosphate via a chemical reaction with the hydroxyl groups of PCDA-HBA resulting in a visible blue to red color change.…”