Indeed, the size of particles II of the modifier is larger than the pores, which are formed by particles II of the matrix. In the case #Chk inhibitor randurls[1|1|,|CHEM1|]# of TiO2-HZD-2, the maxima for necks and cavities are overlapped with a peak attributed to the matrix and cannot be separated. A shift of the peak at 39 nm (TiO2) to 52 nm (TiO2-HZD-7)

has been found. This indicates formation of larger particles III; their size can be estimated approximately from the peak at 52 nm, which is related to pore necks. These particles are evidently located in the cavities of pores, which are caused by the largest particles III of the matrix. The peaks at r > 100 nm for modified membranes are shifted towards lower r values in comparison with the matrix. This indicates HZD deposition inside macropores of the ceramics. Potentiometric transport numbers of counter ions Potentiometric measurements give additional information about the membrane structure. No membrane potential (E m) has been registered for the matrix. E m > 0 V in the case of modified samples. Since the membranes

show anion exchange ability in acidic media [6, 7], Cl− Y 27632 and H+ species are considered as counter- and co-ions, respectively. The transport numbers of counter ions are higher than 0.5 (Figure 8). The following formula was applied to find the size of pores, which are responsible for charge selectivity [23]: Figure 8 Radius of pores, which determine charge selectivity, as a function of C 1 – C 2 (calculations according to formula (7)). Extrapolation of curves to the ordinate axis gives true

value of the radius. Inset: transport number of counter ions as a function of average concentration of the solutions. Extrapolation of the curves to t m = 1 gives the concentration at which the diffusion parts of intraporous double electric layers are overlapped. Membranes: TiO2-HZD-2 Ceramide glucosyltransferase (1) and TiO2-HZD-7 (2). (7) where t is the transport number of Cl− in a solution, k is the shape coefficient (k = 2.8 for pores between globules), η is the surface charge density and C is the average value of concentrations of the solutions from two sides of the membranes. The surface charge density was estimated from sorption measurements as 0.07 C m−2 (TiO2-HZD-2) and 0.18 C m−2 (TiO2-HZD-7). Formula (7) gives the transport number at which concentrations of the solutions from two sides of the membrane (C 1 and C 2) are close to each other. The r value was plotted as a function of C 2-C 1. Extrapolation of the curve to C 2-C 1  = 0 evidently gives the ‘real’ r magnitude, which has been estimated as 8 (TiO2-HZD-2) and 2 (TiO2-HZD-7) nm (Figure 8). It was also assumed that the transport number of counter ions can reach 1, if intraporous diffusion double electrical layers are overlapped.