Preparation Of Chitosan/lanthanum Hydroxide Composite Aerogels And Their Adsorption Property For Phosphorous

Hyperphosphatemia could cause secondary hyperparathyroidism,renal osteodystrophy and vitamin D metabolic disorders.Therefore,a large number of phosphorus adsorbents had been reported for the removal of phosphorus,such as adsorbent resins,natural macromolecular,sporous carbon,ferric oxide based nanocomposites and so on.As it is well known to us,an ideal adsorbent should have high specific surface area and high adsorption capacity.In recent years,aerogel has been used as adsorption materials owing to its higher specific surface area.Lanthanum has a good binding ability to phosphorus,especially has a strong anti-interference ability in a complex system containing phosphorus,which had been reported for phosphorus adsorption materials.Chitosan has many excellent properties,such as nontoxicity,biodegradability,high reactivity and chelating properties and so on,which also had been reported for phosphorus adsorption materials.In this study,we first reported chitosan/lanthanum hydroxide composite aerogel beads for phosphorus adsorption.In this study,chitosan/lanthanum hydroxide?Cs/La?composite aerogel beads were prepared by co-precipitation and supercritical carbon dioxide drying.The structure of Cs/La composite aerogels were observed by scanning electron microscopy?SEM?and Brunauer-Emmett-Teller?BET?test.Fourier transform infrared spectroscopy?FTIR?,X-ray diffraction?XRD?and EDS spectroscopy were used to analyze the chemical structure,crystal structure,chemical elemental composition and the amount of La?OH?₃ of the Cs/La composite aerogels.Thermogravimetric analysis?TGA?and mechanical test was used to study thermal stability and mechanical properties of Cs/La composite aerogel beads.The kinetic adsorption and isothermal adsorption tests were used to investigate adsorption mechanism of Cs/La composite aerogels.In addition,Antibacterial test,cytotoxicity test,hemolysis test,coagulation time test and albumin adsorption test were used to study biocompatibility,and its clinical application prospect was also evaluated.The experimental results showed that the Cs/La composite aerogels exhibited a nanoscale porous structure,and the specific surface area and mechanical properties of the Cs/La composite aerogels increased with the increasing content of La,among which Cs/La₅₀ had a largest specific surface area 172.74 m²/g,and these properties facilitate the adsorption of phosphorus.Adsorption experiments showed that the adsorption process of phosphorus on the Cs/La composite aerogels conformed to the second-order kinetic model and the Freundlich model,and the maximum adsorption capacity was 148.33 mg/g.Furthermore,the inhibition zone test results showed that the higher the La content,the more obvious the antibacterial effect of the Cs/La composite aerogel,and the results of the turbidimetric method showed that all the Cs/La composite aerogels possessed antibacterial property.The results of cytotoxicity test showed that the cytotoxicity increased with the content of La in the Cs/La composite aerogels.In addition,the blood compatibility evaluation results showed that the Cs/La composite aerogel had less albumin adsorption,lower hemolysis rate and slight anticoagulant properties,and thus resulted in a better blood compatibility,indicating its potential application in clinic.