Polypyrrole coated nylon fibers for disk-based solid phase extraction

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The extraction of polar compounds from aqueous matrices is not a easy process due to the high solubility of these compounds into the sample that weakens the interactions with the extractant. Polymeric phases, comprising different monomer in their structure that may establish polar interactions and even ionic, have been widely used to solve this problem. Although there are some commercially available phases, the development of novel ones as well as the design of formats different than the conventional particle-packed column one are attractive research lines. In this context, the use of polymer mats synthesized by electro-spinning allows the fabrication of extraction disks that have special properties like high surface to volume ratio. In addition, they permit the continuous flow of the sample through the extractant phase increasing the sample throughput.

Polypyrrole (PPy) coated nylon fibers have been recently proposed as sorbent for the extraction of azo dyes, which are compounds of toxicological and environmental concern, from water samples [1]. The mat fabrication can be divided in two different steps. At the beginning a nylon mat is obtained by a normalized electrospinning process. After that process, the polymeric mat is coated by PPy thanks to the in-situ oxidative polymerization of pyrrole. Attending to the results the PPy-coated material provides better extraction capacity than the bare nylon-mat. This improvement, which ranges from 2 to 17 times, is directly dependent on the target polarity.

The proposed coated mat has been compared with other sorbents (e.g MIPs, SAX, MAX..) with very positive results. 
  
Reference:

1) Disks solid phase extraction based polypyrrole functionalized core–shell nanofibers mat. Link to the article

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