The increasing need for engineered alloy nanoparticles (NPs) in diverse fields has spurred efforts to explore efficient/green synthesis methods. In this respect, spark ablation provides a scalable and viable way for producing widely different types of mixed NPs. Most importantly, implementation of the spark has the great advantage to combine a wider range of materials, thereby allowing the synthesis of mixed NPs with virtually unlimited combinations. Here we show that polarity reversal of spark discharges between two electrodes consisting of different materials enables synthesis of alloy NPs, while having a good potential to control the broadness of their composition distribution. A model developed in this work provides a tool for tuning the ablation ratio between the electrodes by adjusting the electric characteristics of the spark circuit. The ablation ratio is equal to the mean composition of the resulting NPs. The model predictions are in accordance with measurements obtained here and in earlier works. The unique way of producing alloy NPs by spark ablation shown in this work becomes especially useful when the starting electrode materials are immiscible at macroscopic scale.

A newly developed high frequency spark provides a green, sustainable and versatile platform for manufacturing diverse sub-10 nm particles with well-defined chemical composition that serve as key building blocks.

A major challenge in nanotechnology is that of determining how to introduce green and sustainable principles when assembling individual nanoscale elements to create working devices.For instance, textile nanofinishing is restricted by the many constraints of traditional pad-drycure processes, such as the use of costly chemical procedures to produce nanoparticles (NPs), the high liquid and energy consumption, the production of harmful liquid waste, and multi-step batch operations. By integrating low-cost, scalable, and environmentally benign aerosol processes of the type proposed here into textile nanofinishing, these constraints can be circumvented while leading to a new class of fabrics. The proposed one-step textile nanofinishing process relies on the diffusional deposition of aerosol NPs onto textile fibers. As proof of this concept, we deposit Ag NPs onto a range of textiles and assess their antimicrobial properties for two strains of bacteria (i.e., Staphylococcus Aureus and Klebsiella Pneumoniae).The measurements show that the logarithmic reduction in bacterial count reaches ca. 5.5 (corresponding to a reduction efficiency of 99.96%) when the Ag loading is one order of magnitude less (10 ppm; i.e., 10 mg Ag NPs per kg of textile) than in the textiles treated by traditional wet-routes. The antimicrobial activity does not increase in proportion to the Ag content above 10 ppm as a consequence of a "saturation" effect. Such low loading for