Properties of Gels in Chemistry
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Questions and Answers

What is the primary reason why gels behave like solids despite being mostly liquid by mass?

  • The formation of a three-dimensional cross-linked network within the liquid (correct)
  • The presence of a solid medium within the liquid
  • The presence of a covalent polymer network
  • The dispersion of molecules of a liquid within a solid medium

    • Who is credited with coining the term 'gel'?

  • A group of scientists who studied colloidal networks
  • An unknown 19th century chemist
  • Thomas Graham (correct)
  • A member of the International Union of Pure and Applied Chemistry

    • What is the process of forming a gel called?

  • Colloidization
  • Cross-linking
  • Gelation (correct)
  • Polymerization

    • According to the IUPAC definition, what is a characteristic of a gel?

    <p>A gel has a finite, usually rather small, yield stress</p> Signup and view all the answers

    What type of bonds can cause physical aggregation of polymer chains in a gel?

    <p>Hydrogen bonds</p> Signup and view all the answers

    What is a 'thermoreversible gel'?

    <p>A gel that has regions of local order that are thermally reversible</p> Signup and view all the answers

    What is the primary reason why polyionic polymers contribute more to viscosity in their stretched state?

    <p>Because the ionic charges prevent the formation of tightly coiled polymer chains</p> Signup and view all the answers

    What is the characteristic of a colloidal gel that leads to the rise of elastic behavior?

    <p>The formation of a percolated network of particles</p> Signup and view all the answers

    What happens to the particles in a colloidal gel during the aging phase?

    <p>They slowly rearrange to form thicker strands</p> Signup and view all the answers

    What is the primary characteristic of a gel that is similar to that of its constituent liquids?

    <p>Density</p> Signup and view all the answers

    What is the result of a colloidal gel being subjected to external fields such as gravity?

    <p>It collapses and separates</p> Signup and view all the answers

    What is the behavior of colloidal gels at low amplitudes?

    <p>Linear response rheology</p> Signup and view all the answers

    What is the primary characteristic of hydrogels that allows them to maintain their structural integrity in high water concentrations?

    <p>The presence of cross-links between polymer chains</p> Signup and view all the answers

    What is the primary advantage of hydrogels as 'smart materials'?

    <p>Their ability to encapsulate and release chemical compounds in response to external stimuli</p> Signup and view all the answers

    What is the primary difference between hydrogels and organogels?

    <p>The type of liquid entrapped in the cross-linked network</p> Signup and view all the answers

    What is the significance of the term 'hydrogel' in the context of materials science?

    <p>It refers to a type of polymeric network that can absorb high amounts of water</p> Signup and view all the answers

    What is the primary application of chemomechanical polymers?

    <p>As actuators or sensors</p> Signup and view all the answers

    What is the characteristic of hydrogels that allows them to mimic natural tissue?

    <p>Their significant water content</p> Signup and view all the answers

    What is the primary factor influencing the stimuli-responsive characteristic of a biomaterial?

    <p>The sensitivity of the biomaterial to the stimuli factor</p> Signup and view all the answers

    What is the purpose of implementing intelligent biomaterials in biological systems?

    <p>To enhance tissue regeneration</p> Signup and view all the answers

    What is the result of programming hydrogels with specific molecules?

    <p>Enhancement of biomaterial functionalities</p> Signup and view all the answers

    What is the primary advantage of using click-based orthogonal approaches in hydrogels?

    <p>Simplicity, convenience, and productivity</p> Signup and view all the answers

    What is the advantage of using biomaterials sensitive to external stimuli in tissue regeneration?

    <p>It allows for precise control over biomaterial properties</p> Signup and view all the answers

    What is the result of the reversible bridge via physical crosslinking in hydrogels?

    <p>Structural changes in response to external stimuli</p> Signup and view all the answers

    What is the effect of surface functionalization on intelligent hydrogels?

    <p>It changes the macromolecular structure of the hydrogels</p> Signup and view all the answers

    What is the main purpose of using reversible crosslinking in hydrogels?

    <p>To constitute self-healing characteristics</p> Signup and view all the answers

    What is the goal of using biomimetic approaches in biomaterials?

    <p>To ensure biocompatibility</p> Signup and view all the answers

    What are the two viable options for fabricating intelligent biomaterials?

    <p>Nature-inspired strategies and click-based orthogonal methods</p> Signup and view all the answers

    What is the characteristic of intelligent biomaterials mentioned in the passage?

    <p>Shape memory</p> Signup and view all the answers

    What is the purpose of injectable shape-memory hydrogels?

    <p>To deliver drugs to viable tissues through a minimally invasive treatment strategy</p> Signup and view all the answers

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