Porous structure, reconstitution

Although 3b was not obtained as single crystals, the stmcture was easily estimated by XRPD measurement. For 3b, the intense peak observed at 7.6° for fresh sample shifted to 10.0°, meaning that the initial layer-layer distance was shortened about 2.7 A (Figure 2b). This value is consistent with that of effective space in 3a estimated from the X-ray structure. These results show that the dried complex 3b retains the two-dimensional framework. Exposure of solid sample of 3b to water vapor for three days reproduced 3a as confirmed by XRPD pattern measurement. That is, the dried complex 3b reversibly reincluded water molecules to reconstitute 3a. This structural conversion is classified as Type 1 since the nonporous and porous structures are reversibly obtained by forced release and contact of water guest molecules. 

Basically, all products which contain water can be dried in this manner. After freezing, the ice crystals remain at first at their original location in the structure. If vacuum is applied, the ice sublimates directly without melting. This results in a porous, dry product which has retained its original form. The volume has hardly changed, the cell walls have been little affected, flavour and other main constituents have been treated gently. If the product is to be restored to its former condition - to be reconstituted -only water has to be added. Water sorption in freeze dried materials proceeds faster than in conventionally dried products. For detailed studies on the fundamentals of freeze drying see the literature [1-10]. 

Model of Surface-Bound Membrane on Pt Electrode. From the foregoing discussion of experimental results we can develop a physical model of the surface-bound membrane that consists of two layers, as schematically depicted in Figure 7. The porous, hydrophobic OTS layer provides a structure to anchor the reconstituted membrane layer. Protein molecules with bound lipid may insert into the pores in the OTS layer. The... 

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