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How sodium alginate changes the viscosity in water?

  1. Jun 29, 2017 #1
    Hello everyone.
    I have a question about the sodium alginate (NaC6H7O6)n.

    Recently, sodium alginate is widely used for fabricating edible bottle.
    And I also try to utilize sodium alginate for controlling the viscosity of water.
    I found that with small amount of sodium alginate powder in DI water (0.1 ~ 1.0 wt%), I could get more viscous water which is still fluent, not like edible bottle.

    However, I'm not sure how the sodium alginate increases the viscosity of water.
    What I know is that the sodium alginate is ionized into sodium cation and else.
    But I don't think that is the only reason that makes water viscous.

    Will you let me know the molecular equation of reaction between sodium alginate and DI water??
    Thank you so much!!!
     
  2. jcsd
  3. Jun 29, 2017 #2

    Borek

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    Staff: Mentor

    It is not about a simple reaction - the only reaction is that you have already listed, dissociation into cations and anions. What is important here are properties of the alginate and its interactions with water and other alginate molecules. It is more or less about creating a network of molecules interacting via hydrogen bonds.
     
  4. Jun 29, 2017 #3
    Thank you sir for you reply!
    I'm sorry but I have another question...
    The process that creating a network via hydrogen bonds means not just interaction between alginate and alginate, but also interaction between alginate and water molecule??
    I'm sorry.. Because I'm not the chemistry major student, it confuses me...
     
  5. Jun 29, 2017 #4

    Borek

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    Staff: Mentor

    Yes, water molecules definitely take part in the process. A lot depends on the relative concentrations of water and alginate.
     
  6. Jun 29, 2017 #5

    Borek

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    Staff: Mentor

    In general, viscosity is kind of a measure of how easily molecules in the liquid can move past each other. The stronger the interactions, the more the molecules are "glued" to each other and more difficult to move, the higher the viscosity.
     
  7. Jun 29, 2017 #6

    DrDu

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