We synthesized a phosphonium N-chloramine biocide which has distinctively higher antimicrobial efficacy than the previously developed ammonium counterpart.

To control pathogenic microbial contamination on polymeric material surface, it is pivotal to develop materials with efficacious antimicrobial activity. Two pyridinium N-chloramine precursors containing a siloxane handle were synthesized, characterized, and grafted onto cotton fabrics. The attenuated total reflectance spectra and scanning electron microscope photo analysis indicated that the cotton fabric surface was successfully modified. The resultant chlorinated fabric samples were challenged against bacteria Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Results showed that: (1) the surface modified cotton fabrics displayed satisfactory biocidal efficacy; (2) the precursor structure played a major role on surface grafting and antibacterial activity. This work provides two promising pyridinium N-chloramine precursors which hold potential application for preparing antibacterial textile materials.

Recently there has emerged a lot of work that integrates the compressive sampling theory into watermarking schemes. The subtle changes in local space domain of the signal can lead to distinct disturbance in all the measurements. It will lead to the poor robustness when the watermark is directly embedded into the compressive sampling measurements. To solve this problem, a robust digital watermarking algorithm based on singular value decomposition of compressive sampling measurements is presented in this paper. The watermark is embedded into the singular values of the host image in CS transform domain. Simulation results have shown that the proposed algorithm meets the demand of the transparency and achieves the better robustness to common image processing and geometric attacks. Our algorithm also helps to realize the synchronization of imaging and the watermark embedding.

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