INV- 1007
The absence of highly porous, uniformly nanoporous surfaces places limitations on handling, fractionating, extracting, recovering and concentrating aqueous and nonaqueous samples of chemicals and biological substances, both soluble and insoluble. For example, if the surface is not highly porous, then a process that depends on the surface porosity will be slowed down. A surface that is not nanoporous is limited in its ability to provide size separations or retentions involving dissolved nanosubstances, especially if the size of the pores is not uniform. The porosity, size and shape of a surface for one sample will not be suitable for all samples and processes, making control of these surface properties important. A surface that is non-polar or not highly hydrophilic is prone to causing adsorption losses of nanosubstances that are more or less non-polar from aqueous samples. Such adsorption can build up to clog the surface. A surface that is not highly nonpolar is limited in its ability to process nonaqueous samples. Every known bulk, porous surface is limited in one or more of these properties.
Accordingly, there remains a need for surfaces which allow for size exclusion techniques for particles of small molecular size with little or no loss of sample due to sticking to the surface and which provide a high capacity for a sharp separation based on size. There also is a need for plastic chromatographic surfaces which avoid or minimize the problem of micorpores that causes chromatographic band broadening and losses for small analytes. In other words, a method is needed that fills in or closes these pores, and in a uniform way.
Northeastern University inventors disclose a surface that overcomes some of these limitations and has the following properties: highly porous or nonporous, nanoporous when porous (about 1 nm-10 nm), uniform pore size when porous, controllable and reproducible pore size when porous, controllable in bulk size and shape, and controllable in degree of hydrophilicity. The disclosed compositions and methods offer advantages over current size-exclusion chromatographic and membrane media. The disclosed compositions and methods overcome the mixed-mechanism and pore heterogeneity limitations of current chromatographic packings for aqueous and nonaqueous size exclusion and adsorption separations including improved de-salting of small particle samples as by dialysis.
The hydrogel disclosed here comprises of polymerized vinyl monomers forming a vinyl polymer and an exposed surface layer of polymerized vinyl monomers. The exposed surface layer has a lower porosity than the porosity of an interior layer. Both the exposed surface layer and interior layer have a plurality of polymer-attached initiator residues, polymer-attached helper residues, or a combination thereof, and the porosity of the exposed surface layer allows retention of a particle. The initiator tightened layer in the hydrogel can either be an exposed surface layer or an interior layer.
The composition:
• Overcomes a mixed-mechanism and pore-heterogeneity limitation of many current separation techniques
• Effectively handles, fractionates, extracts, concentrates or recovers selected components of many aqueous, semi-aqueous or non-aqueous samples
• Comprises a multi-layered gel based structure enabling very little or no loss of particles, which makes it preferable over other prior art compositions
Initiator‑tightened Hydrogels disclosed here will find themselves useful for various Biomedical applications including: