Jiangqi Xu,Yujia Bai,Meijiao Wan,Yanhui Liu,Lei Tao,Xing Wang
Paper documents and products are very susceptible to microbial contamination and damage. Fungi are mainly responsible for those biodeterioration processes. Traditional microbicidal strategies constitute a serious health risk even when microbes are dead. Ideal methods should not be toxic to humans and should have no adverse effects on paper, but should own a broad spectrum, good chemical stability and low cost. In this work, we utilize an advanced antimicrobial strategy of surface stereochemistry by applying a coating of a shallow layer of polyborneolacrylate (PBA), resulting in the desired antifungal performance. The PBA-coated paper is challenged with the most common air-borne fungi growing on paper,Aspergillus nigerandPenicilliumsp. Ten percent by weight of the coating concentration or a 19-μm infiltration of PBA is sufficient to keep the paper spotless. The PBA coating also exhibits significant inhibition of spores’ germination. After PBA coating, both physicochemical properties (paper whiteness, pH, mechanical strength) and inking performance display only slight changes, which are acceptable for general utilization. This PBA coating method is nontoxic, rapid and cost-effective, thus demonstrating great potential for applications in paper products.Keywords:antifungal;coating;paper products;polyborneolacrylate;surface stereochemistry
Guanidinylated chitosan (GCS) was prepared by grafting guanidine oligomers onto chitosan under microwave irradiation. The structure of GCS characterized by FT-IR and1H NMR verified the covalent bonding between the guanidine oligomers and chitosan; the effects of molar ratio, reaction temperature, and time were investigated and the degree of substitution of GCS reached a maximum of 25.5% under optimized conditions in this work. The resulting GCS showed significantly enhanced antimicrobial activities. The results obtained from the dynamic UV absorption ofEscherichia coli(E. coli) and atomic force microscopy (AFM) revealed that the deactivation ofE. coliby GCS was due to the destructing of the cell membrane and the prompt release of cytoplasm from the bacterial cells. The adsorption of GCS onto cellulose fibers and the antimicrobial efficiency of the hygiene papers with GCS were also investigated. Microwave irradiation as a green assisted method was applied to promote this reaction. This facile approach allowed chitosan to be guanidinylated without tedious preparation procedures and thus broadened its application as a biocompatible antimicrobial agent.
By utilizing gas chromatography tandem mass spectrometry (GC/MS) and QuEChERS purification technology, a new method was developed for the detection of seven acrylate compounds (methyl methacrylate, butyl acrylate, sec-butyl acrylate, 2-ethylhexyl acrylate, glycidyl methacrylate, n-octyl acrylate, and N-octyl methacrylate) in food contact paper products. Hexane was used as the extraction solvent and carbon nanotubes were used as adsorbents during the QuEChERS purification. The acrylates were separated by an ultra-inert column (DB-5MS UI) and detected in the electron ionization mode of MS with selected ions monitoring (SIM). Under the optimal conditions, the calibration curves for the seven analytes were linear in the range of 5.0–1000 μg L−1 with the correlation coefficients higher than 0.9984. The quantitation limits of the method (S/N = 10) of these acrylates were in the range of 50.0–100.0 μg kg−1. The mean recoveries for paper products at three spiked concentration levels of 50.0–1000 μg kg−1 were in the range of 82.1–106.5%, and the relative standard deviations (RSDs, n = 6) ranged from 1.5% to 5.6%. This method is accurate, simple and rapid, and could be applied to the detection of acrylates in food contact paper products.
危险品化学品经营许可证（带存储）