Solvent Migration
Solvent Migration - Related Videos
01:12
Solvents
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2019
A solvent is a substance, most often a liquid, that can dissolve other substances. Here, the substance being dissolved is called a solute. When a solvent and a solute combine, they form a solution - a homogenous mixture of both the solvent and the solute. Water is a universal biological solvent. Its polar structure allows it to dissolve many other polar compounds. The ability of water to dissolve is governed by a balance between water molecules binding to each other and binding to the solute. A...
06:43
Rotary Evaporation to Remove Solvent
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2023
Source: Dr. Melanie Pribisko Yen and Grace Tang — California Institute of Technology Rotary evaporation is a technique most commonly used in organic chemistry to remove a solvent from a higher-boiling point compound of interest. The rotary evaporator, or "rotovap", was invented in 1950 by the chemist Lyman C. Craig. The primary use of a rotovap is to dry and purify samples for downstream applications. Its speed and ability to handle large volumes of solvent make rotary evaporation a preferred...
09:41
Schlenk Lines Transfer of Solvents
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2023
Source: Hsin-Chun Chiu and Tyler J. Morin, laboratory of Dr. Ian Tonks—University of Minnesota Twin Cities Schlenk lines and high vacuum lines are both used to exclude moisture and oxygen from reactions by running reactions under a slight overpressure of inert gas (usually N2 or Ar) or under vacuum. Vacuum transfer has been developed as a method separate solvents (other volatile reagents) from drying agents (or other nonvolatile agents) and dispense them to reaction or storage vessels while...
08:13
Preparation of Biopolymer Aerogels Using Green Solvents
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Cited by 44 •
2016
A new way for the production of biopolymer-based aerogels by carbon dioxide (CO2) induced gelation is shown. The technique utilizes pressurized carbon dioxide (5 MPa) for the production of biopolymer hydrogels and supercritical CO2 (12 MPa) to convert gels into aerogels. The only solvents needed besides CO2 are water and ethanol.
01:16
Titration in Nonaqueous Solvents
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2024
Most acid-base titrations are performed in an aqueous medium. In aqueous titrations, water competes with weaker acids or bases for proton donation or acceptance, leading to ambiguous endpoints in the titration curve. Water also affects the partial ionization of weak acids or bases. For example, water accepts a proton from acetic acid to form hydronium and acetate ions. The hydronium ion formed is a stronger acid than acetic acid, and the acetate ion is a stronger base than water. As a result,...
FAQs
A concentration gradient provides the driving force for diffusion, so solvent molecules tend to move from a region of higher concentration toward one of lower concentration. The resulting redistribution can change the composition of neighboring materials or phases. In chemical systems, identifying the gradient helps explain why migration occurs and supports predictions about composition changes during processing or storage.
Temperature, solvent volatility, and material structure strongly influence transport rates. Higher temperature can alter how readily molecules move, while volatility affects the solvent’s tendency to leave or redistribute. The structure of polymers, coatings, membranes, or other materials can either facilitate or restrict movement. Considering these variables helps explain differences between formulations and storage conditions.
Sorption describes solvent uptake by a material, whereas desorption describes its release. These processes affect how much solvent remains temporarily associated with a polymer, coating, membrane, pharmaceutical system, or analytical material. Because uptake and release can alter the timing and extent of redistribution, evaluating both processes is important when interpreting composition, performance, or safety changes.
Material structure determines how easily solvent molecules pass through or become retained within a system. Differences among polymers, coatings, membranes, and other chemical materials can therefore produce different migration rates under otherwise similar conditions. This structural influence matters when comparing materials, because it can affect product stability, performance, and the likelihood of solvent-related changes during use or storage.
Evaluation focuses on measuring changes in solvent distribution, composition, material performance, or chemical safety over relevant conditions. Researchers can use these observations to determine whether transport is occurring and whether it produces meaningful effects. Such measurements support assessment of pharmaceutical and analytical systems as well as materials used in packaging, coatings, and other formulations.
The issue becomes important when solvents can move through or interact with packaging materials, coatings, or formulated products. Migration may change composition, reduce expected performance, or raise contamination and safety concerns. Studying transport during processing and storage helps guide material selection and formulation decisions aimed at maintaining product stability and controlling unwanted chemical changes.
Understanding the variables governing transport allows chemists to anticipate changes rather than treat them as unexpected failures. Measurements of migration can reveal potential contamination, composition shifts, or altered material properties. This information supports strategies for controlling transport in pharmaceutical, analytical, packaging, polymer, coating, and membrane systems, improving stability while helping assess chemical safety.