Stable nano-silver colloid production via Laser Ablation Synthesis in Solution (LASiS) under laminar recirculatory flow

Abstract

As nanomaterials find applications in an increasingly diverse range of fields such as wastewater treatment, biotechnology and flexible electronics, the demand for nanomaterials with specific properties has increased. This increase is coupled with an increasing emphasis on nanomaterials with highly-specific properties for specialized applications. Industrially, nanomaterials are produced via wet-chemical techniques which employ the use of solvents and reagents which are environmentally harmful. As we move forward with the use of nanomaterials, the ability to produce nanomaterials in a sustainable manner has become a topic of great significance. Towards this end, Laser Ablation Synthesis in Solution (LASiS) is a physical production technique capable of producing tailored nanomaterial colloids in a sustainable manner. These colloids are produced by ablating a solid target immersed in a solvent using a laser. Typically, LASiS is conducted in a batch process and in small volumes limiting commercial viability. To overcome this, there has been a move towards the use of continuous production via LASiS using flow systems. This allows an increase in nanomaterial yield, resulting in colloids concentrations approaching those of commercial colloids. This work investigates a new production technique incorporating a laminar recirculatory flow system to produce stable high concentration nano-silver colloids. I.

Production of Silver Nano-Inks and Surface Coatings for Anti-Microbial Food Packaging and Its Ecological Impact

“…Nano colloids of smaller particle size distribution absorb the incident light and exhibit absorption peaks around 400 nm wavelength region. However, the colloids consisting of more significant particle size distribution creates light scattering and form broad absorption peak and shift toward the longer wavelength leading to a red shift phenomenon [ 19 , 20 ]. Such red shift was not explicitly observed for any nanoparticle produced in the present study.…”

“…Due to electrostatic repulsion between each individual NPs, colloids with a large positive/negative ξ value generally indicate good stability [ 9 , 20 ]. A small ξ value indicates the Nps aggregation due to the van der Waals attractive forces, leading to colloidal instability [ 9 , 19 ]. The ξ value for LASiS AgNPs colloid produced in this study was −44.22 mV, indicating high colloidal stability.…”

Real-time monitoring and control for high-efficiency autonomous laser fabrication of silicon nanoparticle colloids

“…4 Nanoparticle manufacturing control platform consisting of production and monitoring hardware connected via serial (RS232), digital (USB and Ethernet) and analogue protocols (0-10, 0/24 VDC). Inset: Nps fabrication system process schematic in previous work [24,42]. The laser parameters used for all SiNps production tests are as follows: fluence = 1.83 J/cm 2 , pulse energy = 147 μJ, pulse duration = 700 ps, repetition rate = 10 kHz, spot diameter = 100 μm, liquid flowrate = 10-170 ml/min, and scan speed = 2 mm/s.…”

Laser Ablation Synthesis in Solution and Nebulization of Silver-109 Nanoparticles for Mass Spectrometry and Mass Spectrometry Imaging

“…LASiS employs pulsed laser irradiation to ablate a solid material target submerged in liquid, ejecting NPs from the plasma plume into the surrounding solution . This method allows for stabilizer- and reducing-agent-free NP production. − LASiS produces nanoparticle suspensions of a relatively high chemical purity compared to chemical methods …”