Potentiometric measurement with a Kelvin probe: Contactless measurement of chloride ions in aqueous electrolyte

For the first time the chloride ion concentration in electrolyte is measured using a Kelvin probe. A silver-silver chloride (Ag/AgCl) electrode, which is a chloride ion selective electrode, is used as a sample plate in the electrolyte and the Kelvin probe is used as a reference plate that is vibrating above the electrolyte. The open-circuit potential (OCP) of the Ag/AgCl electrode is a function of the Cl- concentration. The contact potential difference (CPD), measured by the Kelvin probe, gives the OCP of the Ag/AgCl electrode. The measurement does not require any contact between the reference plate and the electrolyte. This approach opens the possibilities for using a Kelvin probe as a contactless reference electrode in electrochemical measurements, such as potentiometry

Components of all-solid-state ion-selective electrodes

An electrochemical sensor is a qualitative and quantitative device that converts a chemical signal to a measurable electrical signal (Yogeswaran and Shen-Ming 2008). Electrochemical sensors can be divided into three classes: potentiometric, amperometric, and conductometric (Stradiotto et al. 2003). A potentiometric sensor measures an electrical potential when no current is present, while an amperometric sensor produces current when a potential is applied between two electrodes. A conductometric sensor assesses conductivity by measuring the electrical resistance of a sample solution. Ion-selective electrodes (ISEs) are potentiometric ion sensors and a subgroup of electrochemical sensors; they are widely used in various fields of biomedical, environmental, and chemical analysis, and physiological sensing (Bobacka et al. 2003; Bakker et al. 2008; Hu et al. 2016). ISEs are classified into three groups, depending on the nature of the membrane material: glass, polymeric or liquid, and crystal or solid (Fig. 16.1) (Faridbod et al. 2007)

Active packaging films based on polyolefins modified by organic and inorganic nanoparticles

Nowadays, the use of polymer films for flexible packaging has gained a widespread importance because of their easy processing, good final properties, light weight and low relative cost. In order to fulfill the needs of increasingly demanding consumers respect to the quality of packaged products, additional capabilities must be incorporated into packaging. In this sense, academic and industrial efforts have focused on new technologies that provide a complementary functionality to the packaging performance. These emerging developments involve active and intelligent packaging, which can attract to consumers, improve product quality and/or balance any detrimental effect. In this context, the use of nanoparticle (NP) modified polyolefins, either in bulk (nanocomposites) or on the surface, allows the inclusion of specific functionalities. These new capabilities enable obtaining active packaging according to the requirements of the product. The aim of this chapter is to analyze the aforementioned approaches for the development of active films by incorporating antibacterial, antifungal and/or repellent functionalities. Currently, several sustainable developments of this type of active films are based on commodity thermoplastics such as poly(ethylene) and poly(propylene). These materials, modified by the incorporation of organic and inorganic NPs, are promising candidates since their final properties can be tailored for packaging application.Fil: Alonso, Yanela Natalin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Grafia, Ana Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; Argentin