A set-up and a method were developed to determine the isoelectric point of metals and metallic alloys samples (stainless steels, inconel, zircaloy, aluminum and dural) by measuring the adhesion rate of negative latex particles. The concentration of polystyrene spheres with surface carboxylate groups (initially 0.5-1 mg L(-1)) in contact with metallic samples was measured as a function of pH and time by turbidimetry. The simulation of measurements by a model predicting the sticking coefficient based on DLVO theory was used for the determination of the isoelectric point from experimental results. It was found that the isoelectric points of aluminum (8.7) and dural (9.1), treated by boiling water, are close to those of hydrated aluminum oxides powders. For stainless steels, inconel and zircaloy, the values of isoelectric points were found to be between 2.4 and 3.0, far below the isoelectric points measured for metallic oxides constituting the alloy surface layer. This difference was explained by two different charging mechanisms: (1) deprotonation of hydroxyl groups on the surface of the metal oxide in suspension or as a thick layer, (2) adsorption of hydroxide ions on a metal surface covered by a thin oxide layer, as observed on hydrophobic surfaces.
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http://dx.doi.org/10.1016/j.jcis.2009.05.005 | DOI Listing |
Curr Issues Mol Biol
January 2025
Department of Biology, Faculty of Sciences, Al-Baha University, Al-Baha 65729, Saudi Arabia.
Understanding the ammonium (NH) uptake and transport systems, particularly genes, is important for plant growth and defense. However, there is a lack of research on identifying and analyzing genes in pomegranate, emphasizing the need for further investigation in this area. Five genes ( to ) were identified, all of which contain the PF00909 domain, a feature of ammonium transporters.
View Article and Find Full Text PDFLangmuir
January 2025
Chemistry and Structure of novel Materials, University of Siegen, Paul-Bonatz Strasse 9-11, 57068 Siegen, Germany.
The surface charge of metal oxides is an important property that significantly contributes to a wide range of phenomena, including adsorption, catalysis, and material science. The surface charge can be predicted by determining the isoelectric point (IEP) of a material and the pH of a solution. Although there have been several studies of the IEP of metal oxide (nano)particles, only a few have reported the IEP of metal oxide films.
View Article and Find Full Text PDFBiotechnol Prog
January 2025
Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India.
Type 2 diabetes mellitus (T2DM) and obesity are critical global health issues with rising incidence rates. Glucagon-like peptide-1 (GLP-1) analogues have emerged as effective treatments due to their ability to regulate blood glucose levels and gastric emptying through central nervous signals involving hypothalamic receptors, such as leptin. To address the short plasma half-life of native GLP-1, a C-16 fatty acid was conjugated to lysine in the GLP-1 analogue sequence to enhance its longevity.
View Article and Find Full Text PDFFood Sci Nutr
January 2025
Centro Tecnológico de la Carne de Galicia Parque Tecnológico de Galicia Ourense Spain.
Sesame protein isolate (SPI) is a highly nutritious plant protein distinguished by its essential amino acid profile. This study investigates the influence of pH on SPI's physicochemical, structural, and techno-functional properties, highlighting its potential as a sustainable protein source for various food applications. Our findings revealed that SPI had a protein content of 90.
View Article and Find Full Text PDFAnal Chem
January 2025
Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
Designing single-template molecularly imprinted chiral sensors for the enantioselective recognition of various chiral amino acids (AAs) is of great importance for chiral analysis. Here, a dummy template-based chiral sensor is developed by using l-alanine (l-Ala) as the dummy template and poly(-phenylenediamine) as the imprinting layer, which can be used for the enantioselective recognition of various chiral AAs such as Ala, tryptophan (Trp), tyrosine (Tyr), cysteine (Cys), and arginine (Arg). Compared with conventional single-template molecularly imprinted chiral sensors, the designed single-template chiral sensor shows great universality for the recognition of chiral AAs since all chiral AAs possess an Ala-analogous segment.
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