Polymers solvation architecture

Bilayer architectures formed in M2(2)3(N03)4 n (where M = Co, Ni and Zn) were one of the first systems of coordination polymers to be shown as porous materials [43]. The bilayer architectures interdigitate with each other leaving small channels in the crystal lattice which were occupied by solvated water molecules. Powder X-ray studies indicate that the water molecules can be removed from the network without causing any distortion or decomposition of the network. The adsorption studies of water removed and dried sample indicated that the material is capable of adsorbing CH4, N2 and 02. About 2.3 mmol of CH4 and 0.80 mmol of N2 or 02 are adsorbed per gram of anhydrous material. The adsorption-readsorption followed the same isotherm, indicating the stability of the network throughout the process. Further, the isotherms for the adsorption-readsorption can be classified as type I in the IUPAC classification [48]. 

Bond distributions can be analyzed for any molecular architecture. The notion of bonds can be taken in its widest meaning to comprise weakly bound solvation networks, molecular meshes, multiple entangled chains (including double-stranded DNA), and cross-linked polymers. Hydration clusters... 

An example of a three-dimensional penetrating network is the solvated [(ZnCl2)3(35)2] 56 [139], The triazine molecules are part of threefold connecting knots (Fig. 7-17). The zinc atoms have a nearly tetrahedral coordination geometry with two N atoms of 35 and two chlorine ligands. A distorted network is obtained. The self-assembly of CUSO4 in water and l,3-bis(4-pyridyl)propane in ethanol results in 57 which presents a three-dimensional architecture sustained by two different types of coordination polymer one-dimensional ribbons of rings and two-dimensional layers (Fig. 7-18) [138]. 

Recently, more complex cylindrical polymer architectures with various copolymer structures have been prepared. For example, core-shell-structru ed amphiphihc CPBs have demonstrated a structural collapse of the interior PS block in pure methanol however, the addition of chloroform to a volume ratio of 1 1 caused the PS chains to become solvated again and to adopt an extended conformation [1]. Likewise, a copolymer with a hnear PS block and a brush block with PAA side chains showed an unusual association in selective solvents typically, it aggregated into star-like micelles in aqueous solution [58]. 

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