Optimization in electrochemistry: new methods in sonoelectrochemistry, electrochemical separations, and education

Optimization is an important component in the development of new ideas and devices with greater efficiency and lower environmental impacts. Mathematical models enable an efficient path to optimize systems. Here, all examples are drawn from electrochemistry. Electrochemistry studies the interactions between electricity and chemistry. Electrochemical systems include batteries, fuel cells, corrosion, synthesis, catalysis, biological processes, and separations.

Classical sonoelectrochemistry (CS) is the application of high frequency sound waves to chemical reactions in a bulk fluid. Incident high amplitude sound waves increase the rate of chemical reactions and enable the synthesis of new materials. Unfortunately, CS wastes energy because most of the input energy is lost to the bulk fluid. Thin layer sonoelectrochemistry (TLS) is an alternative to CS where high frequency sound waves are deposited into a thin layer of fluid instead of a bulk fluid. TLS exploits the physics of a thin layer to amplify and focus input energy to increase rates of chemical reactions. TLS is an effective means to introduce energy to an interface through constructive interference. Here, the mathematical model to optimize TLS is discussed. The model suggests that TLS is competitive with CS. Because TLS is efficient and inexpensive to operate, TLS is more suitable for use in industrial and portable applications.

Electrochemical separation and purification of metals is a crucial step in the production of many portable devices (e.g., batteries, computers, cell phones, and many advanced technologies). In the last one-hundred years, the ideas behind electrochemical separation have changed little and many important separations and purifications are disallowed by this historical but antiquated prospective. Here, a mathematical model used to optimize electrochemical separation is discussed. Optimal conditions are provided that enable use of the mathematical result in practical applications.

Although demonstrations of chemical phenomena are important to sound science education, classroom demonstrations are often either unavailable or involve expensive laboratory equipment. A search of articles in the Journal of Chemical Education suggests a deficiency in demonstrations that are both simple and inexpensive. Simple demonstrations suitable for high school and undergraduate classrooms are important to inform future scientists and members of society to develop an intuitive understanding of scientific phenomena relevant to everyday life. Chemical species move by diffusion; without motion, species cannot come together to react. Here a simple demonstration of the diffusion, based on physical therapy putty, is detailed. Discussion questions are provided that encourage students to think critically, design experiments, and analyze results.

Type 1 Diabetes (T1D) is a disease that limits the ability of an individual to regulate blood sugar. T1D affects nearly 34.2 million people in the US where 11.7 million people are diagnosed globally each year. Without sufficient assessment and regulation of blood sugar, fatal complications can result. At present, assessment of diabetic status involves painful and invasive extraction of blood samples for use with a personal glucose meter. The materials expended with each measurement are expensive with limited shelf life. Recently, alternative body fluids (e.g., sweat, tears, and saliva) have been investigated for biomarkers that indicate diabetic status (e.g., lactate and blood ketones). Here, the initial studies for a non-enzymatic sensor for the biomarker, β-hydroxybutyrate (BHB), in sweat are presented. The feasibility of the method to develop a non-invasive, cost effective sensor is discussed.