Hydrogen-bonded network materials

Given the range of host molecules that may be that be put into network structures and strong current interest in the inclusion properties of crystalline network materials, embedding molecular hosts into hydrogen bonded network structures will continue to be a fruitful and exciting area of inclusion and structural chemistry. 

The dissolution of cellulose and other plant-based material in ILs has been studied by Moyna and Rogers [64-66]. Here, the application of NMR excluded fhe need for solvenf suppression techniques. In combination with and C1/ C1 relaxation measurements, it was found that dissolution of cellulose in [C4CiIm]Cl was promoted by the nonhydrated chloride ions, breaking up the hydrogen bonding networks via the cellulose hydroxyl groups. 

While this notion may conjure up visions of plastic materials it is important to remember that proteins and nucleic acids are also polymers. Many proteins form globular structures and, indeed, may interlock to encapsulate a large volume of space as exemplified by the coatings of capsid viruses. In a prebiotic world, polypeptides could have formed in aqueous solution through the sequential reaction of amino acids. The individual amino acids hydrogen bond donor and acceptor groups, amines, carbonyls and carboxylic acids, would all have helped to keep the molecules in solution. Once a polypeptide had formed, however, many of these would be unavailable as they became incorporated in the hydrogen bond network that formed the secondary and tertiary structure. This would result in a more hydrophobic surface for the protein capsule which would make an effective cell. 

Membranes are used in the pulp and paper industry in a variety of applications in particular for the purification and recovery of water, and for the recovery of raw materials or energy. The pulp and paper manufacturing process requires enormous amount of water to transport the raw materials, to dissolve impurities, to seal various process equipment, to cool and heat, to wash and clean process equipment, and to generate necessary environment for the formation of the hydrogen bonding network between fibers and fillers, which is the basic mechanism of paper formation. Thus, water and its quality are essential issues in the production of pulp and paper. 

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