pH-sensitive polymers are polymers that change their physical properties in response to changes in pH. They include polyelectrolytes that have ionizable groups that become charged or uncharged depending on the pH. The properties that change include chain conformation, configuration, and solubility. This makes pH-sensitive polymers useful for applications like targeted drug delivery where a drug core can be released when the polymer reaches a certain pH. Examples of uses include insulin delivery systems and tumor treatment by targeting medicine specifically to tumor sites. Living polymerization is often used to control the molecular weight of these polymers.
1. Ministry of Higher Education and Scientific Research
University of Sulaimani
College of Science
Department of Chemistry
Prepared by:
hazhir esmail, bryar nahman, barez salah
2. pH-sensitive polymers:
Respond to the changesin the pH of
surrounding medium, Polymers which
exhibit a physical response to their
environment,generallyare
polyelectrolytes(i.e. have ionisable
groups),Can be based on polyacidsor
polybases.
3.
4. The physical properties of the polymer, such
as its chain conformation, configuration, and
solubility, can be tailored by manipulating
the pH or ionic strength.
5.
6. This is very useful behavior, as the core may
by used to carry a payload (e.g. a drug)
which will then be released we it reaches a
certain pH environment.
7.
8. One function of these polymers right now is
for use in targeted tumor treatment, by
targeting the tumor from inside the body,
medicine that could be harmful to healthy
cells is better contained in the area that needs
it.
9. pH‐ sensitive polymers are widely used in the
fabrication of insulin delivery systems to
maintain glucose level. Since insulin has to be
delivered in a precise amount at the exact
time of need, insulin delivery systems need to
be carefully designed.
10. Living polymerization is often used for making
pH sensitive polymers because molecular weight
distribution of the final polymers can be
controlled. Examplesinclude group transfer
polymerization (GTP)
Degree of swelling
Equal to (swollen weight-deswelled weight)/deswelled
weight *100% and determined by massing polymers
before and after swelling. This indicates how much
the polymer swelled upon a change in pH
Applications
Purification and separation
pH sensitive polymershave been consideredfor use in
membranes. A change in pH could change the ability of
the polymer to let ions through, allowing it to act as a
filter.
Biomedical Use
pH sensitive polymers have been used for drug
delivery. For example, they can be used to
release of insulin.
Surface modification
pH sensitive polymers have been used to modify
the surfaces of materials. For example, they can
be used to change the wettability of a surface.
11. Conclusion:
• pH sensitive polymers have the possibility
to do great things for some terrible
treatments by targeting the affected area
• •Polyelectrolytes can act as pH responsive
polymers providing they can act as weak
acids or bases
• •As the polymer is increasingly ionized, the
polymer expands owing to electrostatic
repulsion between charges.
• •pH responsive polymers have the
potential to be used to create a large
number of devices.
12. References:
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