2 research outputs found
Porous Double-Layer Polymer Tubing for the Potential Use in Heterogeneous Continuous Flow Reactions
Functional polymer tubing with an
OD of 1/16 or 1/8 in. was fabricated by a simple polymer coextrusion
process. The tubing was made of an outer impervious polypropylene
layer and an inner layer, consisting of a blend of a functional polymer,
polyethylene-<i>co</i>-methacrylic acid, and a sacrificial
polymer, polystyrene. After a simple solvent leaching step using common
organic solvents, the polystyrene was removed, leaving behind a porous
inner layer that contains functional carboxylic acid groups, which
could then be used for the immobilization of target molecules. Solution-phase
reactions using amines or isocyanates have proven successful for the
immobilization of a series of small molecules and polymers. This flexible
multilayered functional tubing can be easily cut to the desired length
and connected via standard microfluidic fittings
Entrapment and Rigidification of Adenine by a Photo-Cross-Linked Thymine Network Leads to Fluorescent Polymer Nanoparticles
Photo-cross-linking
of nucleobase-containing polymer micelles was
observed to result in fluorescent polymer nanoparticles. By varying
the micelle assembly conditions, it was possible to probe the origins
of this behavior. A number of factors were investigated, including
the effect of omitting one of the nucleobases, blocking hydrogen-bonding
interactions, detaching the nucleobase from the polymer backbone,
and changing the degree of core cross-linking. Spectroscopic investigations
were also carried out to further characterize the fluorescent nanoparticles.
These data revealed that no new small molecule fluorophores were created
during cross-linking and that a dense, hydrogen-bonded network of
photodimerized thymine with entrapped adenine was required for fluorescence
to arise. We conclude that rigidification and immobilization of adenine
in this way leads to the enhancement of an already extant fluorescence
pathway and suggests that synergistic covalent and supramolecular
entrapment of profluorophores may provide a general strategy for the
production of novel fluorescent polymer nanoparticles