Preparation Of Carbon Aerogels And Their Adsorption Of Low Density Lipoprotein

Spherical carbon aerogels (SCAs) have been synthesized through a series of process including of mixing and aging resorcinol-formaldehyde prepolymers with colloidal silica, solvent exchanging, supercritical drying, carbonization and HF aqueous solution etching. The effects of particle sizes of colloidal silica, mass ratios of prepolymers/silica (MR) and drying methods over the networks and the pore sizes of hybrid aerogels/xerogels were also investigated. The pore volume and the mesopore size of SCAs could be accurately adjusted in a wide range respectively. The porosity of spherical carbon xerogels (SCXs) was reversely copied from the SiO2 colloidal nanoparticles with the advantage of uniform pore shape, controllable pore volume and tunable pore size. The relationship between the size of SiO2 colloidal and the pore structure of SCAs/SCXs were also studied, and the result indicated that the pore size increased along with the increase of the size of SiO2 colloidal nanoparticles.The adsorption capability of SCAs with different BET surface areas and pore structures over these biomoleculars from the serum such as low-density lipoprotein (LDL), high-density lipoprotein (HDL), albumin (ALB), immunoglobulin M (1gM), UREA, and creatinine (CREA) were investigated. In order to detect if the SCAs can be developed into the adsorbent-meterials for hemoperfusion, the relationship between the adsorption performance and the pore structure were also studied. The adsorption isotherms of LDL, HDL and ALB were fitted by Langmuir equation. The results indicated that the specific surface area was the key factor to determine the adsorption capacity of SCAs over these small moleculars, which were enhanced along with the increase of the amount of the specific surface area. However, the adsorption capacity of SCAs over the large molecules such as LDL, HDL and ALB had a relationship not only with the specific surface area of SCAs, but also with the pore volume of SCAs and the molecules structure. In conclusion, the adsorption capability over those molecules with a special size can be controlled through adjusting the pore structure of SCAs. Especially for the small molecules with a size smaller than the diameter of the pore structure, the increasement of the surface area of SCAs could remarkably enhance the adsorption capacity of SCAs. The experimental result was well represented by the Langmuir isotherm equation, which demonstrated that the large molecules adsorbed by SCAs were monolayer.The adsorbents of low-density lipoproteins were developed using the method of covalent linkage of SCAs with polyvinyl alcohol and anionic taurine as an affinity ligand. The selective adsorption capacity of the adsorbents over different low-density lipoproteins was also investigated by using the serum of porcine blood. The result indicated that the adsorption capacity over LDL and HDL was 81% and 18%, respectively, and there was not other beneficial biomolecules adsorbed by the adsorbents. All of this indicated that SCAs with the appropriate modification had a great potential to be developed into an adsorbent material for blood purification.