QCM-Based HCl Gas Sensors Using Spin-Coated Aminated Polystyrene Colloids

Simultaneous Cryogenic Radical and Oxidative Coupling Polymerizations to Polyaniline/Polyacrylamide Conductive Cryogels for Gas Sensing

The macro-porous structure of polymer cryogels provides an appropriate channel for the adsorption and transport of substances, endowing its application in the field of electrochemical sensing. The combination mode of a polymer matrix and electro-active substance, particularly the distribution of an electro-active substance in the matrix, has an important effect on the overall performance of the sensor. In this work, through the simultaneous oxidation coupling polymerization of aniline (ANI) and radical polymerization of acrylamide (AAm) under cryogenic condition, conductive composite cryogels were prepared, aiming for the uniform distribution of PANI in the PAAm matrix. The possibility of simultaneous polymerizations was symmetrically investigated, and the obtained PANI/PAAm cryogels were characterized. Due to the acid-doping of PANI, the electrical conductivity of PANI/PAAm cryogels could be modulated with acidic and basic gases. Thus, the performance of the gas sensor was studied by making conductive PANI/PAAm cryogel sheets as resistive sensor electrodes. We found that the content of PANI, the sheet thickness and the dry/wet state of the cryogel influenced the response sensitivity and rate as well as the recovery properties. The response duration for HCl and NH₃ gas was shorter than 70 and 120 s, respectively. The cyclic detection of HCl gas and the alternate detection of NH₃/HCl were achieved. This gas sensor with advantages, including simple preparation, low cost and high sensitivity, would have great potential for the application to monitor the leakage of acidic and basic gases.

QCM-Based HCl Gas Detection on Dimethylamine-Functionalized Crosslinked Copolymer Films

In this work, sensing behaviors and mechanisms of two crosslinked copolymers with dimethylamine and dimethylamide functional groups were compared and investigated for their ability to detect hydrogen chloride (HCl) gas. The crosslinked copolymer films were photopolymerized on quartz crystal electrodes using a micro-contact printing technique. The gas sensing behaviors were analyzed by measuring resonant frequency (Δf) of quartz crystal microbalance (QCM). The HCl binding capacity of photopolymerized films, with a mass between 4.6 and 5.9 μg, was optimized. Under optimized film mass conditions, the poly(2-dimethylaminoethyl methacrylate-co-ethylene glycol dimethacrylate) (DMAEMA-co-EGDMA), poly(DMAEMA-co-EGDMA), film, C2-DMA, showed a 13.9-fold higher binding capacity than the poly(N,N-dimethylacrylamide-co-ethylene glycol dimethacrylate, poly(DMAA-co-EGDMA), film, C0-DMA, during HCl gas adsorption. HCl gas was effectively adsorbed on the C2-DMA film because of the formation of tertiary amine salts through protonation and strong ionic bonding. Furthermore, the C2-DMA film exhibited excellent sensitivity, of 2.51 (ng/μg) (1/ppm), and selectivity coefficient (k* = 12.6 for formaldehyde and 13.5 for hydrogen fluoride) compared to the C0-DMA film. According to the experimental results, and due to its high functionality and stability, the C2-DMA film-coated QC electrode could be used as an HCl gas sensor, with low-cost and simple preparation, in future endeavors.

Acute respiratory distress syndrome due to inhalation of acryloyl chloride

Background

Acryloyl chloride is a highly toxic volatile liquid that can cause pulmonary edema. However, no sufficient treatment reports have been published to date. Here, we report a case of acute respiratory distress syndrome (ARDS) caused by acryloyl chloride inhalation.

Case presentation

The patient was a 36‐year‐old man with accidental exposure to acryloyl chloride. The patient had dyspnea and wet cough, with approximately 88% percutaneous oxygen saturation at room air. He was diagnosed with ARDS and admitted to the intensive care unit. Initially, he was treated with a high‐flow nasal cannula and sivelestat sodium. However, due to the possibility of delayed exacerbation, the patient was switched to methylprednisolone. Oxygenation gradually improved, and the patient was discharged on the day 8 of hospitalization.

Conclusion

We report the case of a patient who developed ARDS with delayed exacerbation after the inhalation of acryloyl chloride, which was treated without endotracheal intubation.