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Periodic patterns resembling spiralswere observed to form spontaneouslyupon unassisted cooling of d-glucaric acid- and d-galactaric acid–based polyamide solutions in N-methyl-N-morpholine oxide (NMMO) monohydrate. Similarobservations were made in d-galactaric acid-based polyamide/ionicliquid (IL) solutions. The morphologies were investigated by optical,polarized light and confocal microscopy assays to reveal pattern details.Differential scanning calorimetry was used to monitor solution thermalbehavior. Small- and wide-angle X-ray scattering data reflected thecomplex and heterogeneous nature of the self-organized patterns. Factorssuch as concentration and temperature were found to influence spiraldimensions and geometry. The distance between rings followed a first-orderexponential decay as a function of polymer concentration. Fourier-TransformInfrared Microspectroscopy analysis of spirals pointed to H-bondingbetween the solvent and the pendant hydroxyl groups of the glucoseunits from the polymer backbone. Tests on self-organization into spiralsof ketal-protected d-galactaric acid polyamides in NMMO monohydrateconfirmed the importance of the monosaccharide’s pendant freehydroxyl groups on the formation of these patterns. Rheology performedon d-galactaric-based polyamides at high concentration inNMMO monohydrate solution revealed the optimum conditions necessaryto process these materials as fibers by spinning. The self-organizationof these sugar-based polyamides mimics certain biological materials. [ABSTRACT FROM AUTHOR]

Inthe present study, sodium deoxycholate (NaDC) was used to producegelation of tris(hydroxymethyl)amino-methane (TRIS) solutions above,below, and near the pKaof NaDC, respectively,which yielded a neutral gelator, a charged gelator, and a mixtureof each. Impacts of ionic interactions on gel formation were studiedin detail and showed that pH can be used to modify many hydrogel propertiesincluding sol–gel temperature, crystallinity, and mechanicalstrength. Several formulations yielded a unique rheological findingof two stable regions of elastic modulus. The release of a small moleculehas been investigated under different hydrogel conditions and at variableshear rate, suggesting utility as a drug-delivery vehicle. It wasalso observed that pH modification of the hydrogels affected nanoparticleformation. Nanoparticles derived from a Group of Uniform MaterialsBased on Organic Salts (nanoGUMBOS), specifically cyanine-based NIRdyes, were templated within the hydrogel network for potential applicationsin tissue imaging. These nanoGUMBOS were found to be size-tunable,although material-dependent. Further understanding of NaDC/TRIS gelationhas broadened the tunability and multidimensional applications ofthese tailored hydrogel systems. [ABSTRACT FROM AUTHOR]

Microstructures of sodium deoxycholate hydrogels were altered considerably in the presence of variable tris(hydroxymethyl)aminomethane (TRIS) concentrations. These observations were confirmed by use of X-ray diffraction, polarized optical microscopy, rheology, and differential scanning calorimetry measurements. Our studies reveal enhanced gel crystallinity and rigidity with increasing TRIS concentrations. The tunable hydrogel microstructures obtained under various conditions have been successfully utilized as templates to synthesize cyanine-based fluorescent nanoGUMBOS (nanoparticles from a group of uniform materials based on organic salts). A systematic variation in size (70–200 nm), with relatively low polydispersity and tunable spectral properties of [HMT][AOT] nanoGUMBOS, was achieved by use of these modified hydrogels. The gel microstructures are observed to direct the size as well as molecular self-assembly of the nanomaterials, thereby tuning their spectral properties. These modified hydrogels were also found to possess other interesting properties such as variable morphologies ranging from fibrous to spherulitic, variable degrees of crystallinity, rigidity, optical activity, and release profiles which can be exploited for a multitude of applications. Hence, this study demonstrates a novel method for modification of sodium deoxycholate hydrogels, their applications as templates for nanomaterials synthesis, as well as their potential applications in biotechnology and drug delivery. [ABSTRACT FROM AUTHOR]