**4. Preparation of organic–inorganic polymer hybrids by ion-exchange reaction of ladder-like PSQ with organic polymer**

Hybrids composed of organic and inorganic materials usually exhibit improved performance properties compared with conventional composites, mixtures on a micrometer scale (µm), due to their unique phase morphology and improved interfacial properties. For these reasons, nanostructured organic–inorganic hybrids have attracted considerable attention from both fundamental research and applications points of view (Usuki et al., 1993; Chujo, 1996). In particular, the organic–inorganic hybrids obtained from the synthetic polymers as organic species are important industrial materials.

In this section, the author describes the preparation of an organic–inorganic polymer hybrid (PSQ–PAA hybrid) with regular higher-ordered structure composed of the aforementioned PSQ-NH3+Cl– as the inorganic species and poly(acrylic acid sodium salt) (PAA-Na) as the organic species by the ion-exchange reaction (Kaneko et al., 2005b). To obtain PSQ–PAA hybrid, the ion-exchange reaction was performed by pouring PSQ-NH3+Cl– aqueous solution into PAA-Na aqueous solution (Scheme 3b).

The IR spectrum of PSQ–PAA hybrid displayed absorptions at 1044 and 1144 cm**–**1 assigned to the Si–O bond of the PSQ, and absorptions at 1407 and 1558 cm**–**1 due to the COO– of the PAA, indicating that the product consisted of both organic and inorganic polymers. The CHN elemental analysis data showed that the C/N molar ratio for the product was 5.92. From this value, the ratio of the functional groups of the two polymers, *i.e.*, NH3+ and COO–, was calculated to be *ca*. 1 : 1.

80 Ion Exchange Technologies

poly(acrylic acid sodium salt).

**Scheme 3.** Ion-exchange reaction of PSQ-NH3+Cl– with (a) *n*-octanoic acid sodium salt and (b)

**reaction of ladder-like PSQ with organic polymer** 

polymers as organic species are important industrial materials.

into PAA-Na aqueous solution (Scheme 3b).

**4. Preparation of organic–inorganic polymer hybrids by ion-exchange** 

Hybrids composed of organic and inorganic materials usually exhibit improved performance properties compared with conventional composites, mixtures on a micrometer scale (µm), due to their unique phase morphology and improved interfacial properties. For these reasons, nanostructured organic–inorganic hybrids have attracted considerable attention from both fundamental research and applications points of view (Usuki et al., 1993; Chujo, 1996). In particular, the organic–inorganic hybrids obtained from the synthetic

In this section, the author describes the preparation of an organic–inorganic polymer hybrid (PSQ–PAA hybrid) with regular higher-ordered structure composed of the aforementioned PSQ-NH3+Cl– as the inorganic species and poly(acrylic acid sodium salt) (PAA-Na) as the organic species by the ion-exchange reaction (Kaneko et al., 2005b). To obtain PSQ–PAA hybrid, the ion-exchange reaction was performed by pouring PSQ-NH3+Cl– aqueous solution The XRD pattern of the resulting insoluble product showed formation of a hexagonal phase and the *d*-values of the diffraction peaks were different from those of PSQ-NH3+Cl–(Scheme 3b), indicating formation of not a macroscopic mixture but the molecular-scale mixture of two polymers, *i.e.*, organic–inorganic hybrid.
