Preparation Of New Calix[4]Arene-β-Cyclodextrin Coupling Products And Their Gel Rheological Behavior

In order to seek new host compounds with the expectation of synergistic recognition effect and prepration of supramolecular gel basing on the host compounds, two supramolecular parents β-cyclodextrin and calix[4]arene were coupled using chemical bond. In this paper, basing on the theoretical basis of supramolecular chemistry and shear rheology, synthesis of single-substituted calix[4]arene-β-cyclodextrin coupling products and prepration of supramolecular gel and gel rheology behavior research were exhibited as follow:1. The 5,11,17,23-tetra-tertbutyl-25,27-dihydroxyl-26-(N-dexoxy-β-cyclodextrin-aminoethyl aminocarbonyl methoxyl)-28-(ethoxycarbonyl methoxyl)-calix[4]arene (Short for single-amide coupling product) and 5,17-bi-tertbutyl-11-formyl-23-(N-dexoxy-β-cyclodextrin-aminoethyl amino methyne)-25,27-dihydroxyl-26,28-bis (ethoxycarbonyl methoxyl) calix[4]arene (Short for single-schiff base coupling product were synthesized by using 5,11,17,23-tetra-tertbutyl-25,27-dihydroxyl-26,28-bis (ethoxycarbonyl methoxyl) calix[4]arene and N-(2-aminoethyl) amino dexoxy-β-cyclodextrin (Short for amino-substituted cyclodextrin) as starting materials. The structures were characterized by’H NMR, FT-IR, MS(Maldi-tof).2. The lowest concentration and the phase transfor temperature of these two coupling products gel were researched. Results showed that the lowest concentration of single-amide and single-schiff base coupling products gel were 50 mg·mL-1 (DMSO/H2O(V:V=1:1)) and 58.33 mg·mL-1 (DMSO/H2O(V:V=0.5)) respectively, the phase transfor temperature were 35℃ and 40℃ by itself.3. The mechanical properties of single-amide coupling products gel (Dynamic time sweep, Dynamic angular frequency sweep, Dynamic strain amplitude sweep, Steady viscosity curves of shear rate sweep, and Dynamic temperatrue sweep) were studied.Result showed that this was thermo-responsive gel on the normal concentration of 50 mg—mL-1. This showed viscoelastic on the condition of 20 mg·mL-1 and 30 mg·mL-1. On low concentration, surrounding weakly shear force and dynamic angular frequency sweep(ω) had a significant impact on microgel structure, nevertheless, this performed weakly influence at high concentration. Strength and shear viscosity of the supramolecular gel could be controlled by the concentration of gel. Results of dynamic strain amplitude sweep(γ0) indicated that gel network structure was stabe under lower strain amplitude, however network structrue was damaged under higher strain amplitude(γ0=0.01%-10%), showed shear-thinning behavior, steady viscosity curves of shear rate sweep(η) demonstrated that supramolecular gel performed shear-shinning behavior of non-newtonian fluid in the whole range of shear rate.4. The mechanical properties of single-schiff base coupling products gel were preliminary researched.Results of dynamic angular frequency sweep of different temperature on 58.33mg·mL-1 made clear that supramolecular gel of single-schiff base coupling was thermo-responsive gel. The gel presented typicial elastic solid response and G (G under the low temperature(10℃). Gel network structure would destoryed when temperature was continued to increase, G and G would be decreased.Results of steady viscosity curves of shear rate sweep on different concentration at 25℃ and on different temperature at 58.33mg·mL-1 indicated that viscosity of gel could be adjust by concentration and temperature, steady viscosity of gel were decreased by increasing shear rate, and sweep presented typicial shear thinning behavior. Viscosity of sample in different temperature decreased with increasing of temperature and viscosity of sample at the different concentration increased with increasing of concentration.