Controllable Synthesis Of Polyhydroxy Polymers And Interaction With Metal Ions

Polyhydroxy polymers have significant chemical diversity,good biocompatibility and unique ion specificity.Polyhydroxy polymers have important applications in the field of metal ion detection.In this thesis,two well-defined polyhydroxy polymers—catechol-based polymers and ribose-containing polymers—are designed and synthesized based on the reversible coordination between polyhydroxy polymers and metal ions,and were used to detect metal ions in water.First,catechol-based polymer micelles with strong fluorescent effect were prepared by Cu（0）-Mediated Reversible Deactivation Radical Polymerization（Cu（0）-RDRP）combined with ring-opening reaction.The relationship between fluorescence intensity and concentration,p H and the type and concentration of metal ions were studied.The results show that the catechol-based polymer micelles have specific recognition ability for Fe³⁺.The catechol-based polymer micelles have good detection effect on Fe³⁺solutions with concentrations as low as 0.3 mmol L^-1,and the fluorescence quenching rate can reach 97%.Also,the catechol-based polymer micelles can effectively recognize Fe³⁺solutions with concentrations as low as 0.1 mmol L^-1,and the fluorescence quenching rate is more than 50%.Secondly,the catechol-based polymer micelles were used to reduce chloroauric acid in situ to prepare catechol-based polymer/gold hybrid nanomaterials capable of stable dispersion.Gold nanoparticles have fluorescent effect.Metal ions can enhance the fluorescence intensity of gold nanoparticles by reducing the interaction between catechol groups and gold nanoparticles.Gold nanoparticles have specific recognition ability for Cu²⁺and can effectively recognize Cu²⁺solutions with minimum concentrations of 0.4 mmol L^-1.Studies have shown that high concentrations of Cu²⁺can induce gold nanoparticles to aggregate and precipitate,and low concentrations of Cu²⁺can effectively increase fluorescence intensity of gold nanoparticles.Finally,ribose-containing polymers with temperature-sensitive effect were prepared by Cu（0）-RDRP combined with azide-alkyne click chemistry reaction.Through a series of characterization methods such as Dynamic Light Scattering（DLS）,Thermogravimetric Analysis（TGA）,Differential Scanning Calorimetry（DSC）,the interaction between the ribose-containing polymers and the metal ions were proved,and the polyhydroxy functional groups in the polymer were able to achieve effective coordination with the metal ions.The ion specific effect of ribose-containing polymers in high-concentration salt solutions follows the Hofmeister series.The low critical solution temperature of the polymers decrease with increasing anion concentrations.However,the ion specific effect no longer follows the Hofmeister series in low-concentration salt solutions.The low critical solution temperature of the polymers increase abnormally with the increase of the anion concentrations,which can be based on the Hofmeister effect of temperature-sensitive polymers can achieve detection of metal ions.