1. Could you explain the significance of your article to the non-specialist? 

Crystalline layered silicates (e.g. magadiite, ilerite, and kanemite) possess a two-dimensional nanospace with periodic reactive silanol (SiOH) groups between the silicate layers. The chemical modification of the nanospace has attracted much attention because there is a possibility to construct novel open framework structures like zeolites. The conventional modification for the layered silicates is silylation with organochlorosilanes or organoalkoxyxilanes, forming layered organic-inorganic nanocomposites. These nanocomposites, however, have no vacant space in the interlayer due to the presence of the bulky and flexible alkyl groups. The present method is a new synthetic approach to produce an open-frame work structure in the nanocomposites, which can be expected to contribute to the design of new open-framework structures.

2. What has motivated you to conduct this work? 

As stated above, the conventional layered organic-inorganic nanocomposites possess no porosity. This yields less selectivity to the accommodation of specific guest molecules in the interlayer, leading to limited application. The situation motivated us to construct the open-framework structure in the nanocomposites. We tried to immobilize a rigid 'pillar' between the layers in order to retain the interlayer nanospace. Organic-bridged alkoxysilane precursors, which have been extensively studied in the development of novel silica hybrid materials, were a good candidate as the 'pillar'. As described in our paper, the precursor bridges the layers through anisotropic condensation between the precursor molecules and the layers, resulting in the formation of the open-framework structure in the interlayer.

3. Where do you see this work developing in the future? 

The present method confers two advantages to the development of the organic-inorganic hybrid nanocomposites. First, the open-framework structure shows the high microporosity indispensable for application as an adsorbent, or to gas-separation or sensor devices. Second, the organic spacer (e.g. phenylene, biphenylene, terphenylene and other aromatic compounds) in the precursor enables us to design the surface property by the further introduction of various organic-functional groups in the interlayer, permitting control of selectivity and activity in catalytic applications. These advantages will stimulate numerous applications in the materials field.

4. Are there any particular challenges facing future research in this area? 

The inorganic part in the organic-inorganic hybrid composites have been mainly based on the silicate or silica compounds although there are diverse inorganic compounds in the material fields. The further utilization of other inorganic compounds will be a significant challenge for the development of this area in the future.