Electrical and dielectric properties of water

Abstract

___________________________________________________________________________________A água é uma das substancias mais importantes do planeta. É composta por hidrogênio e oxigênio, ambos de grande importância química e para vida humana. Embora na literatura científica existam vários estudos sobre as propriedades físicas e químicas da água, muito ainda pode ser estudado sobre essa substância. Neste estudo, descreveremos as propriedades elétrica e dielétrica da água na fase líquida, assim como, a impedância, constante dielétrica, polarização molar e momento dipolo em função da frequência (1-20 kHz) na faixa de temperatura entre 288 e 314 K. As medidas de constante dielétrica e impedância foram realizadas com auxílio de um analisador de impedância. Ademais, foi utilizado um sistema capacitivo de placas paralelas, todo experimento foi blindado para minimizar os efeitos de interferência eletromagnética (ruído) e conectado ao aterramento da rede elétrica do laboratório. Os valores de momento de dipolo foram estimados aplicando a teoria de Kirkwood com base na definição de campo local de Onsager para líquidos polares. Palavras-chave:Propriedades elétrica e dielétrica, Polarização molar e momento de dipolo, Teoria de Kirkwood.Water is one of the most important substances on planet. It's constituted by hydrogen and oxygen elements, both of great importance chemistry and fundamental to human life. Although there are many studies about your physical and chemical properties in the scientific literature, much can be studied yet about this substance. In this study we report the electrical and dielectric properties of the water in liquid phase, such as impedance, dielectric permittivity and dipole moment as a function of frequency (1-20 kHz) in the temperature range between 288 and 314 K. The impedance and dielectric permittivity measurements were carried out in experimental apparatus equipped with an impedance analyzer. In addition, a capacitive system of parallel plate was and entire experiment was shielded to minimize electromagnetic interference effects (noise), and connected to the grounding of the laboratory electrical network. The dipole moment values were estimated applying the Kirkwood's theory based on the definition of Onsager's local field for polar liquids.

Radical ligand-containing single-molecule magnets

“…One way to determine the strength of this coupling involves the temperature-independent paramagnetism (TIP) of the open-shell singlet ground state through employing Griffith's methodology for metal ions with unquenched orbital angular momentum [321]. Another method to quantify the strong exchange coupling in 28 is through employing the Hubbard molecule model (HMM) [322,323], which is essentially the Hubbard model [324] adapted to a single molecule [325]. This bonding model encloses the electron correlation and represents an extension of Hückel theory by adding a parameter that considers electron pairing energy [326].…”

Extraction of protein from food waste: An overview of current status and opportunities

“…Moreover, the review explains the relevance of why organic solvents (e.g., ethanol, methanol, and 2‐propanol) are more commonly preferred than water. Mainly because water is known to have a high dielectric constant or relative permittivity (ideally 80.4 at 20 °C) (De Sousa et al., 2017). Permittivity is one of the fundamental parameters in MAE process that affect the propagation of electric field.…”

“…In simpler terms, relative permittivity explains how well a material, in this case water, allows electric field to travel through it. Methanol (33), ethanol (25.3), and 2‐propanol (21.8) have a lower relative permittivity than water, thus better suited (De Sousa et al., 2017; Lee & Park, 2011). Phongthai et al.…”

Is the Time-Domain Reflectometry (TDR) Technique Suitable for Moisture Content Measurement in Low-Porosity Building Materials?

“…In contrast to the dielectric permittivity of air (ε air ), which is approximately equal to one regardless of the air temperature, the dielectric permittivity of water (ε water ) changes according to the water temperature. In the literature, there are several functions available that express the dielectric permittivity of water as a function of the water temperature [5][6][7][8]. Despite the variety of studies, it is of general consent that the dielectric permittivity of water at 18 • C is approximately equal to 81.…”