I am trying to synthesis a non-covalent, bulk molecularly imprinted polymer by using precipitation method. Organochloride pesticide was chosen as template and MAA as functional monomer along with EGDMA cross linker...I have chosen the BPO as initiator, and Dichloromethane as porogen solvent. I followed the procedure below for the experimental workflow, I could not achieve the expected efficiency within the obtained polymer...It could not retain the pesticide efficiently, therefore I kindly ask for your opinions regarding the given procedure below and which modifications must be applied to this recipe?
1mmol template + 4 mmol MAA + 50 ml DCM was mixed and agitated for 30 mins. Afterward, 20 mmol EGDMA and BPO was added to glass tube. After degassing and nitrogen purging, polymerization reaction took place for 24 hr at 60C. Template removal by consecutive washes by using MeOH:acetic acid was accomplished and resulting polymer was dried, mashed.
Performance tests were applied as SPE and dispersive SPE (as Quechers) formats...
Thanks in advance, Emir...
I would go through the followings:
1- Check whether most of the template has been extracted from the MIP matrix by washing. Then do the rebinding test.
2-Play with the polarity strength of the binding solvent.
Also, please be aware that the smashing of the polymer destroys most of the specific cavities!
Dear Ismail
Firstly you should ensure that your template can form stable complex with functional monomer and if soichimetry of this complex is 1:2 or higher. If not there is no chanse for imrinting and you need to find other set functional monomers. For that purpose, you should go for UV-Vis/NMR/TCI titrations or DFT calculations and find the proper template/functional monomers system. Only then you have chance for efficient imprinting.
1. You should ensure that all templates are extracted. It is easy. Just calculate before imprinting, during imprinting process by checking the remaining solvent, and after washing. You can use HPLC, it takes a short time.
2. You use a lot of crosslinker. This may affect your polymer matrix. If you add a lot of crosslinker, highly cross-linked polymer will be formed. Consequently, the template cannot be released easily.
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