This ppt contains separation mechanism on membranes and review of an article

1. SEPARATION OF ENANTIOMERS USING
POLYMER MEMBRANES
Presented by,
K. Lavanya
Roll No:1008-17-884-009
Department of Pharmacy, Osmania University.
Under the guidance of
Dr.Y.Soujanya,
Senior Scientist
Polymers and functional materials
Indian Institute of Chemical Technology, Hyderabad.

2. CONTENTS
I.INTRODUCTION
II. LITERATURE REVIEW
III. AIM AND OBJECTIVE
IV.REFERENCES

3.  Non superimposable mirror
images
 same physical properties
(B.p, m.p, density, etc.)
 Rotate plane polarized light
the same magnitude but in
opposite directions (+ or -)
 Significant different
biological properties
Enantiomers
Source: "Types of Isomers"— Presentation

4. Polymer membranes
• A thin layer of semi-permeable material that is used for solute
separation.
• These membranes preferentially allow a specific enantiomer to
adsorb to or diffuse into the membrane.
• This specificity is generated by chiral recognition sites in the
membranes such as chiral side chains, chiral backbones, or
immobilized chiral selectors in polymeric chiral separation
membranes.
• They act as selective barriers in the resolution process, and they
preferentially transport one enantiomer due to the stereospecific
interaction between the enantiomer and chiral recognition sites.
Source: Polymeric Membrane for Separation
(Gas Separation Membranes; Polymer Separation
Membrane) Global Research Insight 2018-2023
Polymer membrane

5. Polymer membranes
The mechanism of chiral separation on polymeric membranes can be categorized as:
• Diffusion-selective membranes: Made of an intrinsically chiral polymer without
specific foreign chiral selectors.
E.g. albumin or other proteins, chiral polysaccharide chains or segments, DNA, crown ether
derivatives and oligopeptides.
• Sorption-selective membranes: Made by embedding or immobilizing chiral selectors
in polymer membranes or on the membrane surfaces and these membranes have less
selective diffusion but show highly selective sorption.
E.g. chiral selectors include crown ether derivatives,cyclodextrin, albumin and other proteins, and
DNA.

6. Mechanism of separation on polymeric membranes
Source:DOI: 10.1039/C5CS00510H (Review Article) Chem. Soc.
Rev., 2016, 45, 2785-2824

7. Need for enantiomer separation
 Important aim for industrial practice ,research and
especially in pharmaceutical industry.
 Human body is highly chiral selective ,it will interact with
each racemic drug differently and produce different
pharmacological activity.
 One isomer may thus produce the desired therapeutic
activities, while the other may be inactive or produce
unwanted side effects.
Thalidomide disaster: thousands of babies were born with malformed limbs due to misuse of S-
thalidomide for pregnant women.

8. WHY POLYMER MEMBRANES?
Current resolution techniques:
 Expensive
 Inefficient
 Time consuming
 Low amount of sample
Membrane-based enantioseparation
techniques:
 Easy to scale-up
 Save energy
 Continuously operated
 Efficient

9. LITERATURE REVIEW
Dialdehyde Bis( silyl enol ether)
Mukiyama aldol reaction
lipase
SCH polymer

10. OH
HO
Trans Sobrerol Salbutamol
Propranolol hydrochlorideAtenolol
Captopril
Racemic compounds

11. Enantioselective permeation
 From the study, it was found that S-isomers of all the racemates were enantioselectively adsorbed
and R-isomers were permeated through the membrane.
 The permeation of S-isomers were suppressed by the S-isomers of the chiral polymers present in
the membrane due to self association behaviour.
 The permeation performance of the membrane depends on the asymmetric carbon present in the
polymer.
 Thus the self association behaviour of the adsorbed isomer on the membrane is reasonable.
 Mechanism of resolution on polymer membrane is based on binding capacities and binding
affinity between chiral selectors and two enantiomers.
 The selectivity is highly dependent on separation process, composition of membrane and its
electrochemical properties in addition to the pore size.

12. OBJECTIVE
 To understand the
mechanism of resolution
on polymer membrane.
 To study the permeability
and selectivity parameters
using computational
methods.

13. REFERENCES
1. S. Hazarika, “Enantioselective Permeation of Racemic Alcohol through Polymeric
Membrane,” J. Mem. Sci., vol. 310, pp. 174-183, 2008.
2. S. Hazarika, S. Borthakur, P. G. Rao and N.N. Dutta, “A Novel Method for
Preparation of Chiral Polymer Useful for Membrane Application,” Polymer Journal,
vol. 41(2), pp.1067-107, 2009.
3. S. Hazarika, N.N. Dutta and P.G. Rao, “A Quantitative Structure Activity Relationship
Study on Permeation of Amino acids in Enantioselective Membranes,” Appl. Mem. Sc.
& Technol, vol.2, pp. 13-29, 2006.
4. Rui Xie,a Liang-Yin Chua and Jin-Gen Dengb , “Membranes and membrane
processes for chiral resolution” ,2008 DOI: 10.1039/b713350b.