Development of a photocontrollable aqueous two-phase system for a novel separation method
Multi-scale and/or multi-disciplinary approach to process-product innovation
Novel Separation Techniques (T3-8)
Keywords: separation, aqueous two phase system, photochromic chromophore, spiropyran, dextran
Jun-ichi Edahiro, Kimio Sumaru*, Toshiyuki Takagi, Toshio Shinbo, Toshiyuki Kanamori
Research center of advanced bionics, national institute of advanced industrial science and technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, JAPAN
*k.sumaru@aist.go.jp
An aqueous two-phase system essentially consists of two immiscible aqueous solutions of different polymers. Due to the minimal invasive nature, it was employed to separate naturally derived substances. However there are some technical problems in the aqueous two-phase separation: long separation time, and low selectivity. In this study, we suggest a novel separation system based on an aqueous two-phase system of which phase separation can be switched by light irradiation. A novel aqueous two-phase system, which shows a photoinduced phase separation, has been developed with the photochromic dextran synthesized by substituting 0.3 mol% of hydroxyl groups with the photochromic chromophore, 6-nitrospiropyran. For an aqueous solution containing this photochromic dextran and poly(ethylene glycol), it was observed that the solution, which had been uniform in the dark, quickly separated into two phases through blue light irradiation within 1 min. Photoisomerization of 6-nitrospiropyran was confirmed to shift the phase separation temperature of this aqueous two-phase system by up to 30 ºC.
In the photoresponsive aqueous two-phase system, which was developed in this study, unlimited interfacial area could be obtained instantaneously while phase separation was induced from a single uniform phase by light irradiation. In this situation, it is anticipated that an ideal separation operation can be achieved in which all substances in the solution are in contact with the interface. Furthermore, an advantage is that compared with cases whereby a similar operation is carried out through varying the temperature, there is no fear of degeneration caused by temperature change during phase separation. We expect that this novel separation mechanism is promising for a high-throughput separation method of biological substances.
Presented Tuesday 18, 11:20 to 11:40, in session Novel Separation Techniques (T3-8).
