materiały: Properties of water

Evidence: 100 • authority: 72

Water (H2O) is a polar inorganic compound that is, at room temperature, a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on the surface of Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe (behind molecular hydrogen and carbon monoxide). Water molecules form hydrogen bonds with each other and are strongly polar. This polarity allows them to dissociate ions in salts and bond to other polar subs…

Evidence: 45 • authority: 72

Water is an inorganic compound with the chemical formula H2O. It is a transparent, tasteless, odorless, and nearly colorless chemical substance. It is the main constituent of Earth's streams, lakes, and oceans. Water is also the fluid of all known living organisms, in which it acts as a solvent. Water, being a polar molecule, undergoes strong intermolecular hydrogen bonding which is a large contributor to its physical and chemical properties. It is vital for all known forms of life, despite not providing food energy or being an organic micronutrient. Due to its presence in all organisms, its chemical stability, its worldwide abundance, and its strong polarity relative to its small molecular…

Evidence: 45 • authority: 72

Heavy water (deuterium oxide, 2H2O, D2O) is a form of water in which all hydrogen atoms are hydrogen-2 isotope or deuterium (2H or D, also known as heavy hydrogen) rather than the common hydrogen-1 isotope (1H, also called protium) that makes up most of the hydrogen in normal water. The presence of the heavier isotope gives the water different nuclear properties, and the increase in mass gives it slightly different physical and chemical properties when compared with normal water. Deuterium is a heavy hydrogen isotope. Heavy water contains deuterium atoms and is used in nuclear reactors. Semiheavy water (HDO) is more common than pure heavy water, while heavy-oxygen water is denser but lacks…

Evidence: 28 • authority: 92

Water Structure within Ternary Solvents Suggests Nanophase Formation.. Water's unique solvating properties and its interactions with hydrophobic surfaces play crucial roles in various chemical processes ranging from self-assembly to phase separation. This study investigates the structure and hydrogen bonding of water in ternary solvent systems composed of water, a cosolvent (acetone, dimethylformamide, or dimethyl sulfoxide), and an oil (2-hexanone or 2-pentanone) to reveal how solvent organization changes upon oil addition. Using Raman spectroscopy coupled with multivariate curve resolution, we probe changes in hydrogen bonding as a function of ternary composition. Counterintuitively, repl…

Evidence: 28 • authority: 72

In chemistry, a hydrogen bond (H-bond) is a specific type of molecular interaction that exhibits partial covalent character and cannot be described as a purely electrostatic force. It occurs when a hydrogen (H) atom, covalently bonded to a more electronegative donor atom or group (Dn), interacts with another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac). Unlike simple dipole–dipole interactions, hydrogen bonding arises from charge transfer (nB → σ*AH), orbital interactions, and quantum mechanical delocalization, making it a resonance-assisted interaction rather than a mere electrostatic attraction. The general notation for hydrogen bonding is Dn−H···A…

Evidence: 22 • authority: 80

The Hydrogen Bonding Properties of Cytosine: A Computational Study of Cytosine Complexed with Hydrogen Fluoride, Water, and Ammonia

Evidence: 22 • authority: 92

Balancing Hydrogen Bonding and Crystallinity in Enzymatically Functionalized Lignin-Poly(vinyl alcohol) Composite Films.. Poly(vinyl alcohol) (PVA) is a promising biodegradable polymer; however, its reliance on petroleum and incompatibility with raw lignin additives hinder sustainable PVA composite development. In this study, mechanically robust PVA/functionalized acid-soluble lignin (fLGAS) composite films were developed by means of aqueous solution casting without toxic chemical crosslinkers. Commercial kraft lignin was enzymatically modified using laccase from Coriolopsis spp., improving its compatibility with the PVA matrix. Molecular characterization confirmed the formation of an inter…

Evidence: 22 • authority: 72

Variations in pressure and temperature give rise to different phases of ice, which have varying properties and molecular geometries. Currently, twenty-two crystalline phases have been observed, including ice Ih, Ic, ..., XXI. In modern history, phases have been discovered through scientific research with various techniques including pressurization, force application, nucleation agents, and others. On Earth, most ice is found in the hexagonal Ice Ih phase. Less common phases may be found in the atmosphere and underground due to more extreme pressures and temperatures. Some phases are manufactured for nano scale uses due to their properties. In space, amorphous ice is the most common form as…

Evidence: 21 • authority: 92

Supramolecular polymer adhesives based on multiple hydrogen bonding: advances and perspectives.. With the rapid evolution of modern electronics, energy storage, and semiconductor industries, the demand for high-performance adhesives has shifted from a sole focus on adhesion strength to multifunctionality and sustainability. Conventional thermosetting adhesives are limited by their irreversible covalent networks and therefore inherently struggle with challenges such as end-of-life disassembly and recyclability. Supramolecular polymer adhesives based on multiple hydrogen bonds have emerged as promising alternatives owing to their dynamic reversibility. This perspective systematically discusse…