Term
| What phase is solid > liquid |
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Definition
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| What phase is liquid > solid |
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Definition
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Term
| What phase is liquid > gas |
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Definition
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Term
| What phase is gas > liquid |
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Definition
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Term
| What phase is solid > gas |
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Definition
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Term
| The boundary between 2 phases when they co-exist is called _________ |
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Definition
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Term
| Behavior of molecules forming the interface are often significantly different from those in the _____of each phase |
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Definition
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Term
| Interfaces can be divided into two main categories |
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Definition
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Term
| Describe Liquid interfaces |
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Definition
| Liquid phase with a gaseous phase or a liquid phase with another liquid phase |
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Term
| Describe Solid interfaces: |
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Definition
| Solid with gas or solid with liquid. |
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Term
| What do you call Gas-liquid: body of water exposed to atmosphere |
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Definition
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Term
| What possible interface is Liquid-liquid |
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Definition
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Term
| What possible interface is Liquid-solid |
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Definition
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Term
| What possible interface is Solid-solid |
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Definition
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Term
| Molecules that reside in the bulk of a phase are surrounded by similar molecules and so experience ______ forces from all directions |
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Definition
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Term
| Molecules at interface are subjected to _____ forces . |
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Definition
differing.
High attractive forces from molecules of same phase and lower from other phase |
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Term
| Define Interfacial /Surface tension |
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Definition
| It is the resistance of a liquid to spread out and increase its surface area. |
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Term
| What causes surface tension? |
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Definition
| – Surface tension is caused by the difference in the intermolecular forces experienced by molecules at the surface of a liquid and those experienced by molecules in the interior. |
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Term
| Molecules at the surface experience ______ forces from molecules that are situated _______ and _______ to the molecules on the surface. |
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Definition
| attractive, below and adjacent |
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Term
| The molecules at the surface of the liquid experience an _____ force toward the bulk. |
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Definition
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Term
| How does inward force create surface tension? |
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Definition
| The inward force pulls the molecules of the interface together and contracts the surface and thus results in surface tension. |
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Term
| Lung surfactant _______surface tension of alveolar membrane so alveoli can inflate easily and not collapse after expiration |
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Definition
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Term
| No lung surfactant leads to________ ________ _______ especially in case of premature babies due to premature lungs |
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Definition
| respiratory distress syndrome |
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Term
| What are the affects of drug delivery systems |
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Definition
– Solubilization and dispersion of drugs
– Suspension and emulsion stability
– Adsorption of drugs |
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Term
| Define interfacial tension and what unit does it use? |
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Definition
Interfacial tension is the force per unit length that exists at the interface between two immiscible liquid phases.• The unit for interfacial tension is dynes/cm
• γ = F /2 L |
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Term
| Interfacial tension causes immiscible liquids from ... |
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Definition
| mixing with each other e.g. oil and water |
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Term
| Interfacial tension also causes... |
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Definition
| resistance and shrink surfaces |
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Term
| What type of molecule is a Surface Active Agent |
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Definition
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Term
| Surface Active Agent are used for... |
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Definition
| Used to disperse one immiscible liquid in another |
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Term
| How do Surface Active Agents work? |
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Definition
| Place themselves at the interface of the immiscible liquids and reduce tension |
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Term
| Surface Active Agents have an affinity for ... |
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Definition
| both polar and nonpolar solvents |
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Term
| Depending on the number of polar and non-polar groups present amphiphiles could be predominantly ... |
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Definition
| hydrophilic or lipophilic. |
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Term
| List an example where Amphiphiles have a balance between polar and non-polar groups |
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Definition
| straight chain alcohol (eg. ethyl alcohol) is hydrophilic and miscible with water. |
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Term
| When the number of carbon atoms increases, the hydrophilicity of the compound _______ and hydrophobicity_______ |
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Definition
decreases, increases
For example, solubility of amyl alcohol (C5H11OH) is lower than ethyl alcohol (C2H5OH) and acetyl alcohol (C15H33OH) is practically insoluble in water. |
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Term
| Surface active agents are classified based on ... |
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Definition
| their ability to dissociate in aqueous solution. |
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Term
| What do anionic surfactants do in relation to the current topic |
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Definition
| Ionizes in solution and the hydrophobic group is negatively charged |
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Term
| What do cationic surfactants do in relation to the current topic |
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Definition
| These surfactants ionize in solution and the hydrophobic group is positively charged. |
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Term
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Definition
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Term
| Certain molecules and ions tend to concentrate (move toward interface) in the interface when ... |
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Definition
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Term
| When molecules and ions move toward interface the concentration of those molecules at the interface are ______ than their concentration in the bulk of the liquid. |
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Definition
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Term
| adsorption or positive adsorption can be defined as... |
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Definition
| preferential partitioning of a molecule to the interface |
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Term
| In the case of positive adsorption, surface tension ... |
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Definition
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Term
| Some materials may tend to concentrate in the bulk (for example inorganic electrolytes) and this type of adsorption is called ... |
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Definition
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Term
| In case of negative adsorption, surface tension and surface free energy ... |
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Definition
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Term
| Adsorption can also occur on ... |
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Definition
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Term
| How is Adsorption different from absorption? |
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Definition
| Adsorption is a surface effect and absorption is a process in which liquid or gas penetrates in the capillary space of an absorbing medium |
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Term
| Surfactants being amphiphilic in nature tend to concentrate at what type of interfaces? |
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Definition
| gas-liquid and liquid-liquid interfaces. |
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Term
| In Adsorption Of Surfactants At Liquid Interfaces the amphiphile is adsorbed at ... |
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Definition
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Term
| In the case of an air-water system, hydrophobic chains face ... |
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Definition
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Term
| In the case of oil-water system, the hydrophobic tails ... |
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Definition
| remain associated with oil phase. |
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Term
| For amphiphiles to be able to concentrate at the interface, there has to be... |
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Definition
| a proper balance between water and oil soluble groups |
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Term
| Depending on the ________ ___ _______ in the liquid phase, surfactants may form two types of monolayers |
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Definition
| solubility of surfactants |
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Term
| What are the two types of monolayers |
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Definition
• Soluble monolayer
• Insoluble monolayer |
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Term
| Give an example of Insoluble monolayer |
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Definition
| acetyl alcohol forms an insoluble monolayer on water |
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Term
| Give an example of soluble monolayer |
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Definition
| amyl alcohol forms a soluble monolayer on water |
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Term
| Emulsions are stabilized by the presence of_________ _______ between the ______ and water phases. |
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Definition
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Term
| To provide optimum stability to emulsions know the ... |
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Definition
| the area occupied by surfactants at the interface |
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Term
| The efficiency of wetting agents and detergents depends on the ... |
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Definition
| concentration of material adsorbed. |
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Term
| Monolayer of adsorbed amphiphiles can be used as____ ______ _____ for biologic membrane. |
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Definition
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