Frozen polymerization for aligned porous structures with enhanced mechanical stability, conductivity, and as stationary phase for HPLC

Highly ordered monolithic structures by directional freezing and UV-initiated cryopolymerisation. Evaluation as stationary phases in high performance liquid chromatography

“…Using this method, Okaji et al 10 prepared honeycomb monolithic polymers using a UV-curable urethane diacrylate monomer (in concentrations between 5 and 10 wt%) and dioxane as solvent. Barrow et al 9 reported the synthesis of methacrylate-based aligned polymers using different monomer concentrations (from around 5 to 20 wt%) and camphene or dioxane as solvents. The prepared polymers showed improved mechanical stability as the monomer concentration increased.…”

“…It should have a reasonable high melting point so it remains solid during the polymerisation step. Camphene 9 and dioxane [9][10][11]13 with melting points of 50 and 12 C respectively were used in this synthetic approach. Using this method, Okaji et al 10 prepared honeycomb monolithic polymers using a UV-curable urethane diacrylate monomer (in concentrations between 5 and 10 wt%) and dioxane as solvent.…”

Composite Hydrogels with Tunable Anisotropic Morphologies and Mechanical Properties

“…18,20,26,32,[40][41][42] A more efficient strategy would be simultaneous freeze-casting and cross-linking, as demonstrated for anisotropic hydrogels of agarose 34 and glutaraldehydecrosslinked gelatin 43 . This alternative approach can be readily implemented in composite hydrogels, in addition, to greater morphological control achieved by varying the ratio of hydrogel components.…”

“…19,24,25 In bioseparation, control over the shape anisotropy of hydrogel pores may enhance the selectivity of the filtration of biological species and/or minimize the pressure drop across the matrix. 26 Anisotropic hydrogels have been fabricated by applying tensile or compressive forces to shape-anisotropic gel components, e. g., carbon nanotubes or cellulose nanocrystals, within an isotropic hydrogel matrix. 13,15,27,28 Self-assembled fibrils of peptide amphiphiles 26 or lamellar bilayers of polymerizable surfactants 25,27 have been oriented within a hydrogel matrix using shear forces.…”

“…26 Anisotropic hydrogels have been fabricated by applying tensile or compressive forces to shape-anisotropic gel components, e. g., carbon nanotubes or cellulose nanocrystals, within an isotropic hydrogel matrix. 13,15,27,28 Self-assembled fibrils of peptide amphiphiles 26 or lamellar bilayers of polymerizable surfactants 25,27 have been oriented within a hydrogel matrix using shear forces. Alternately, dielectrophoresis has been utilized to align carbon nanotubes in an isotropic hydrogel matrix.…”