Functional Membrane Based On Supramolecular Structure Of Porphyrin And Its Application

Porphyrin has been widely used in biology, chemistry, and physics, because of their special chemical structure and optoelectronic properties. Based on the charges and two supramolecular structures of TPPS, we immobilized TPPS on the surface of EVAL-PDMAEMA and PAN membrane. Inducing chiral aggregation behavior of TPPS on the membrane was studied, and prepared supramolecular intelligent membrane and layer-by-layer of self-assembled composite nanofiltration membrane. The supramolecular structures of TPPS on the influence of the membrane performancewas studied.TPPS can be loaded on the surface of the EVAL-PDMAEMA membrane by electrostatic interaction. At pH>2.2, TPPS formed H-aggregates; at pH<2.2, the aggregates of TPPS changed from H-aggregates to J-aggregates. Increasing the grafting degree of the membrane and the adsorbing capacity of TPPS were in favour of the formation of J-aggregates. In the induced of L-/D-Trp, the J-aggregates of TPPS can produce chiral induction signal. There were two approaches to fabricate supramolecular chirality, one is called the (induced pre-aggregation)-adsorption method, another is defined as the adsorption-(induced aggregation) method. The results showed that the pending-type chiral aggregates showed single CD bands and rod-like morphology; and the wrapping-type aggregates exhibited CD couplets and dispersed spherical morphology. The aggregates of TPPS on the achiral membrane expressed the chiral information of the excess enantiomer.The J-aggregates and H-aggregates had a remarkable differences on the size, when adjusting the pH, the aggregates can realize the reversible conversion, based on it, the EVAL-PDMAEMA/TPPS presented pH-responsibility. At pH above 3.0, TPPS assembled into H-aggregates on the membrane surface, which had little effect on the morphology of the membrane, and the membrane showed relatively higher water flux and lower PEG20,000 rejection. When pH was decreased to 1.0, TPPS transformed into J-aggregates which showed worm-like structure with large size, and then the membrane showed better surface wettability, decreased water flux and increased PEG20,000 rejection. Higher loading amount of TPPS and higher grafting content of PDMAEMA helped membrane show more notable pH-sensitivity. The novel supramolecular assembly-based membrane with good stability has potential for selectively permeating and rejecting some solutes in water treatment.In the process of preparation of nanofiltration membrane via layer-by-layer self-assembly based on supermolecule structure of TPPS, we choosed the PAH as polycation and the PSS as polyanion. The results showed TPPS can increase the Zeta potential of the membrane, and the rejection was improved. Due to TPPS that between assembly layers played a supporting role, increase the flux of self-assembled membrane. When the pH was decreased to 1.0, the TPPS formed J-aggregates, which had a rod-like structure and reduced the pore size of membrane. This result in the membrane flux reduced and the rejection increased.