Location: Home - News - Industry News

China develop new separation method of function colloid nanoparticle

"Chemical Resource" State Key Laboratory of functional separation of colloidal nanoparticles achieve new progress

The National Natural Science Foundation of Science and Technology and Ministry of Education, supported by Beijing University of Chemical Technology Chemical Resource Professor Sun Xiaoming State Key Laboratory of Stanford University and Professor Dai Hongjie American cooperation, a functional separation of colloidal nanoparticles new method: the density gradient ultra-centrifugation separation rate. The use of colloidal particles under the centrifugal force field through the density gradient region at different rates, by controlling the centrifugal the parameters of the nanoparticles according to size, density and agglomeration of such differences to be separated.

Different sizes and morphology of nanoparticles has to study size effect, quantum effect and the basis of features such as surface effects. For a long time, people mainly rely on improved synthetic method to obtain monodispersed nanoparticles. However, due to the temperature field and concentration field heterogeneity and the harsh reaction conditions, sometimes making monodisperse nanoparticles were more difficult. Synthesis tools as an effective complement to, Professor Sun Xiaoming, etc. have developed a new method to achieve separation of nano-particles according to particle size, density and agglomeration of the various separation.

This principle previously limited to DNA, proteins and vaccines such as the separation of biological macromolecules. The main process is to be separated (eg, biological macromolecules) placed on top of a certain density gradient zone in the ultracentrifugation conditions, the material will be separated under centrifugal force migration. Because different materials are separated in different size and density will be different buoyancy and viscous resistance to the density gradient in the same orientation in the performance of different motor behavior, so after a certain time to be separated according to size and density of material characteristics up to a certain spatial distribution.

Professor Sun Xiaoming ideas such as expanding research, based on colloidal nanoparticles and biological macromolecules in the scale and density on the similarity of shifts in the principle of transplantation to the system of separation of colloidal nanoparticles. By FeCo @ C magnetic nanoparticles and Au nanoparticles in the solution of iodixanol gradient separation in the study, found that the concentration of the solution to adjust the density gradient, centrifuge speed and time parameters, can achieve 1.5 ~ 20nm particle size segregation. Research also pointed out that this method also used for separation of colloidal particles of different densities, such as FeCo @ C nano-colloidal particles in solution of carbon nanotubes can be achieved with the magnetic particles are more complete separation of particles. To further verify the separation efficiency, a mixture of 5nm, 10nm and 20nm Au colloid three types of monodisperse particles, experiments show that only 15 minutes by a centrifuge to restore the original single-dispersion. Research published in a recent issue of Angew. Chem. Int. Ed. (2009, 48, 939 -942) on. With traditional dialysis, filtration, chromatography and electrophoresis methods, the method for completion in the liquid density gradient separation, prevent any solid - solid interaction of colloidal particles resulting from the loss and separation system failure, and through adjustment gradient density gradient difference, temperature and time parameters to achieve separation of the different separation, with universal, efficient, time-saving products and systems without loss of trade benefits of reconstruction, showing exciting and potential separation.

Fig. 1 colloidal particles by density gradient ultra-centrifugation to separate the mechanism of rate diagram.

Fig. 2 to recover Au nanoparticles show the effect of separation: (A) three kinds of monodispersed Au particles and the mixture centrifuged photos. Red area shows the location of Au particles. (BD) Three initial TEM photos Au particles (EG) restored TEM photos Au particles.