| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
In order to investigate the porous silica gel structure and of the encapsulated protein structure in the gel, we performed small angle neutron scattering measurements. By means of the contrast-variation method, we found that the matching point of the porous silica gel was 60% D_2O.The calculated matching point of the porous silica gel, in which all porosities were occupied by water, is the point of 67% D_2O.This difference indicates the presence of the many encapsulated H_2O molecules in the porous silica gel. Assuming that the scattering arises from an uncorrelated, freely jointed chain, which are called by a Gaussian chain, we analyzed the porous silica gel structure. The scattering function I(q) is given by I(q)=f^2(q)S_G(q) where S_G(q) denotes the scattering function of the Gaussian chain and f(q) is the single particle form factor. S_G(q) is given by S_G(q)=2(e^<-X>+x-1)/x^2 where x=q^2R_G^2.R_G is the mean radius of gyration of the Gaussian chain. For spherical particle, the form factor can be written as f(q)=3{sin(qr_0)-qr_0cos(qr_0)}/(qr_0)^3 where r_0 is the particle radius. The parameters evaluated by a least squares fitting are r_0=10* and R_G=100*. This sample was prepared from the mixture of 1ml TMOS'sol and 1.5ml phosphate buffer. In the sample prepared from the mixture of 1ml TMOS'sol and 3ml phosphate buffer, the mean radius of gyration of the Gaussian chain increased to 133*. The radius of gyration of 253* was observed in the sample prepared from 1ml TMOS'sol and 6ml phosphate buffer mixture. The particle radius did not show remarkable changes. These results show that the length of the Gaussian chain become longer when the fraction of the water is higher in the preparation mixtures. The analyzes of the sample encapsulated protein are now in progress.
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