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There is an increasing interest to enhance resistance to pathogens on the powder-coated surface. Traditional silver antimicrobial agents are hard to endure high curing temperature and lead to the yellowness of the surface appearance. Commercial sources usually cut down silver loading (less than 2.5w%) to avoid the color change and this will result in low inhibitory effect and poor durability. To improve the antimicrobial performance and maintain the appearance, Ag+, Cu2+, Zn2+ ternary inorganic antimicrobial agents on Linde A zeolite supports were prepared in this study. The silver content of this agent is increased to 8-10w% and the coated surface exhibits high antimicrobial efficiency. The coating appearance shows little adverse color change (∆E=1.47) when adding 2w% amount of agent. The reduction rate of this agent was over 99.99% after 6hrs for E. coli, S. aureus and C. albicans according to ASTM E2180-07 standard, and the paint film can maintain over 99% reduction rate even for 11 cleaning cycles. XP...

The efficiency of silver containing antimicrobial coatings depends on the release of the active component (silver ions) embedded in the coated surfaces. Fabrication and analysis of antimicrobial additives to powder coating were investigated in this research. An ion exchange process was used to incorporate the silver and copper ions into the synthetic zeolite LTA. Salts of these active agents in different combinations were tested to optimize the antimicrobial additives by achieving the highest concentration of active components. Yellowing and non-durable problems of this type of coating were studied and solution was proposed and examined. It was found the reduction of silver ions to Ag o during the high temperature curing step causes the coating turns yellower and reduced the durability of the antimicrobial function. The release rate of the active components from the surface to the contaminated environment can be further controlled by using polymeric encapsulation on the additive. Transfer efficiency of the additives in the resin system during the spraying was improved by a PGS treatment. The improved additives from this study showed excellent antimicrobial efficiency and durability. Toxicity produced from the coated surface was proved from LDH analysis.

Modified natural chabazites functionalized with silver–copper were used as an additive to develop antimicrobial powder coated surfaces. Two chabazites (named as LBC and LBN) were modified to enhance the ion-exchange properties by conditioning with sodium salt. The cation-exchange capacity (CEC) of those zeolites was improved from 3.31 meq. g−1 and 3.46 meq. g−1 to 3.77 meq. g−1 and 4.09 meq. g−1 respectively and they were used to produce silver–copper modified zeolites. In order to achieve durable and efficient antimicrobial additives, different combinations of these ions were used by varying the reaction time. These additives were used with a polyester resin system to produce ultrafine powder coated surfaces. Silver was utilized as an antimicrobial agent, whereas copper was used to prevent the reduction of silver during the coating process. All materials including the raw, modified and functionalized zeolites were characterized using XRD and TGA to observe the effect of treatment. ICP-OES was used for elemental analysis at every experimental stage. Color analysis proved that copper prevents silver from being reduced and maintains the color of the coated surface, which is comparable to the control surface. These coated surfaces have shown homogeneous antibacterial properties with excellent durability against E. coli for extended periods. Cell toxicity was evident from the LDH analysis of the fresh and used antimicrobial surfaces.

Legumes are important constituents of Bangladeshi diet and provide a considerable portion of dietary proteins, minerals, and vitamins. The ready to eat soup powder prepared from legume and vegetables in the laboratory can provide an improved nutritional status. Incorporating processed rice, corn, and processed wheat flour as the starch source, three different samples of soup powder were prepared. Protein source was derived from legumes and vegetable paste was used as a mineral source. All these three developed formulations have a protein value ranging from 19.00 to 19.40% and calorie content 347 to 353 Kcal/100g (Table 2). Sensory evaluation of the products revealed a reasonable acceptance of the sample prepared from wheat flour. The selected soup powder contains 19.40 percent protein and 350 Kcal of energy per 100g. Commercially available soup powder was compared with all samples in the light of its nutritional values. Protein and energy content of the selected sample is comparable with the commercial one, which contain only 7.77 percent protein and 297 Kcal energy per 100 g. Prepared soup powder is also a good source of carbohydrate and minerals, mainly iron, calcium & phosphorus. Storage study was conducted to determine the shelf life of the developed food product. Statistical analysis shows that there is no significant difference during the storage of the selected soup powder for six months DOI: http://dx.doi.org/10.3329/bjar.v32i3.547Bangladesh J. Agril. Res. 32(3) : 451-459, September 2007