Guinier intercept

Figure 8.4 presents a sketch of the graphical procedure. According to Eq. (8.26) the intercepts in this Guinier plot are... 

This leads to the well-known Guinier relationship [6] (Fig. 4). The experimental In 1(0) data are plotted against to give a strai t line of slope - / q/3 and intercept In I 0) ... 

The different regimes of interest are illustrated in Figure 8 (drawn afla Ref. 30) for spherical particles. The cross-section has been normalized to its value at K=0. The oscillations only occur when the particle radius, a, is well-defined, and become damped as the radius takes on a spread of values(26). Figure 8a shows the Guinier region at low K. From equation 26, the intercept at K=0 is equal to C (ft,P - pn ) (Np fV). Thus, the initial portion cf the scattering curve gives information about the i cle size and volume fraction, provided die scatto ing contrast and instrumentation factors are known. 

This is the Guinier region. It provides information concerning polymer mass or radius, which is determined by the intercept and slope of a plot of log l(K) versus [124]. 

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