Liquid marbles as microreactors for qualitative and quantitative inorganic analyses

Abstract

Conventional qualitative analysis of ions from inorganic salts and acid-base and redox titrations require relatively large volumes of solution and hence require more reagent and generate relatively large amount of waste. Liquid marbles can be used to cut down the volume of solution and by extension the amount of reagent and volume of waste generated. Liquid marbles were used for qualitative analysis of ions from inorganic salt solutions and acid-base and redox titrations. This was compared with the conventional methods which require milliliters of solution. Fumed silica or fluorinated sericite clay particles of varying degrees of hydrophobicity were used to prepare the marbles. A drop of a test reagent was then placed on the marble, merging with it and initiating a chemical reaction. The characteristic reactions between a salt solution and a test reagent in the marbles were observed provided the reaction was clearly marked by a color change. Concentrations, calculated from the volume at the end-point, compared closely (p ≤ 0.05) with the known ones as well as those calculated from the bulk titration method that requires milliliters of solution. This indicates that the liquid marble method which rather requires microliters of solutions is reliable. These findings are especially important in microfluidics which utilizes microliters of solutions.

Identification of the best medium for experiments on chemical computation with Belousov–Zhabotinsky reaction and ferroin-loaded Dowex beads

“…7, 8) and all beads on the right (No. 4,5,6) are Dowex 50W-X8 with mesh size 16-50. First three electric potential steps φ 1 = 0.0 V, φ 2 = − 1.5 V, φ 3 = 0.0 V do not induce oscillations inside any ferroin loaded Dowex beads in this experiment.…”

“…Both liquid computers and living organisms need chemical energy to operate. They use non-electric inputs and CO 2 is one of waste products of information processing [6]. Nature-made liquid computers, like for example the Human brain, seem to be highly optimized for energy consumption.…”

Long‐Lived Liquid Marbles for Green Applications

“…Whilst this is a hinderance in terms of lifetime it allows for the effective use of LMs for liquid-gas phase reactions, such as the copolymerization of 1,3-dienemonomer [184] and detection of ammonia and hydrochloric acid. [9] LM microreactors have also been employed for Janus particle synthesis through dopamine polymerization, [185] methylene blue degradation using catalytic LMs, [186] qualitative and quantitative inorganic analysis, [187] and as electrochemical [188] and photothermal microreactors. [189] Their use can also be extended into microbioreactors for enzymatic hydrolysis, [16] the polymerase chain reaction [149,150,190] and rapid blood typing by forming blood LMs.…”

Liquid Marbles as Miniature Reactors for Chemical and Biological Applications

“…The formation rate of the violet colour from the reaction of glucose and its detection reagent was measured to determine the correlation coefficient between the reaction rate and glucose concentration. By using liquid marbles containing test reagents, Tyowua et al were able to identify cations and anions, as well as conduct acid-base and redox titrations without introducing any external actuation fields [77]. These tests were done simply by merging droplets of test reagents with liquid marbles and observing the colour change of the indicators.…”