Construction Of Nanochannel Based On Crown Ether And Its Research On Ion Separation

Biological ion channels transport specific ions through lipid membranes,while repelling other ions of similar size and other metal ions.For example,biological K⁺ion channels,ions pass through the K⁺channel selective filter(SF),allowing potassium ions to permeate quickly and selectively.This feature puts biological ion channels in an important position in ion screening.The realization of this ion selectivity in artificial solid-state nanochannels will make new separation techniques possible,but it is still very challenging.To simulate the function of biological potassium ion channels,it is necessary to understand its core structure and functional mechanism.In the research shows a highly selective biomimetic artificial ion channels containing crown ether components.1.The paper introduces a highly selective biomimetic artificial sodium channel built on newly synthesized porous crown ether crystals.The modified material is mainly synthesized by the reaction of 1,10-diaza-18-crown-6-ether and zinc nitrate hexahydrate.This material has many pores,and the extremely narrow pores show strong steric hindrance to both K⁺(0.27 nm)and hydrated polyvalent ions(>0.4 nm).The results show that the artificial sodium channel has Na⁺/K⁺selectivity of 15,which is equivalent to that of biological channels.The Na⁺/Ca²⁺selectivity is up to 523,which is nearly two orders of magnitude higher than the biological channels.And the Na⁺/Mg²⁺selectivity is up to 1128.This work helps to understand the structure-performance relationship of ion-selective nanopores.2.According to the high selectivity of the artificial solid sodium ion channel,we changed the crown ether to be aza-15-crown-5-ether,and studied the ion selectivity.In the detection of current,we found that this channel promoted the transport of lithium ions,and showed better lithium ion transport performance when the ion concentration was 0.1M.The selectivity of Na⁺and Mg²⁺was 3.4 and 196respectively,which showed optimal transport concentration in some pores and membranes.