Photocrosslinkable Polymeric Bicontinuous Microemulsions.

We present an approach to photocrosslink bicontinuous microemulsions derived from ternary blends of poly(methoxyethyl acrylate) (PM, = 4200 g/mol), poly(hexyl methacrylate--coumarin methacrylate) (PHC, = 6800 g/mol), and PM--PHC diblock polymer ( = 19,400 g/mol) in a phase-selective manner, enabling structural characterization at an unprecedented level of detail. This strategy utilizes the [2 + 2] photodimerization reaction of coumarin derivatives to covalently crosslink blends without the use of harsh reagents or disruptive thermal treatment, thus preserving the intricate network structure throughout curing. The resulting crosslinked bicontinuous microemulsions exhibited rubbery behavior at elevated temperatures, achieving an elastic shear modulus of nearly 1 MPa at 70 °C, owing to the presence of the three-dimensional co-continuous network morphology.

Influence of Charge Fraction on the Phase Behavior of Symmetric Single-Ion Conducting Diblock Copolymers.

A series of symmetric poly[(oligo(ethylene glycol) methyl ether methacrylate--oligo(ethylene glycol) propyl sodium sulfonate methacrylate)]--polystyrene (POEGMA-PS) diblock copolymers were synthesized as a model system to probe the effect of charge fraction on the phase behavior of charged-neutral single-ion conducting diblock copolymers. Small-angle X-ray scattering (SAXS) experiments showed that increasing the charge fraction does not alter the ordered phase morphology (lamellar) but increases the order-disorder transition temperature () significantly. Additionally, the effective Flory-Huggins interaction parameter (χ) was found to increase linearly with the charge fraction, similar to the case of conventional salt-doped diblock copolymers.

Ultrahigh Molecular Weight Hydrophobic Acrylic and Styrenic Polymers through Organic-Phase Photoiniferter-Mediated Polymerization.

As many physical properties of polymers scale with molecular weight, the ability to achieve polymers of nearly inaccessibly high molecular weight provides an opportunity to probe the upper size limit of macromolecular phenomena. Yet many of the most stimulating macromolecular designs remain out of reach of current ultrahigh molecular weight (UHMW) polymer synthetic approaches. Herein, we show that UHMW polymers of diverse composition can be achieved by irradiation of thiocarbonylthio photoiniferters with long-wave ultraviolet or visible light in concentrated organic solution.

Influence of an immune-modulatory feed supplement on performance and immune function of beef cows and calves preweaning.

The ability to positively alter immune and stress response with nutritional compounds is of great interest and importance to the beef industry. There is a proprietary product (OmniGen-AF [OG]; Phibro Animal Health, Quincy, IL) reported to have performance-enhancing benefits by altering animal response to stress and immune challenges. The objective of this 2-yr research project was to study the effect of supplementing OG to beef cows and their calves on breeding and growth performance.

Adaptable Crosslinks in Polymeric Materials: Resolving the Intersection of Thermoplastics and Thermosets.

The classical division of polymeric materials into thermoplastics and thermosets based on covalent network structure often implies that these categories are distinct and irreconcilable. Yet, the past two decades have seen extensive development of materials that bridge this gap through incorporation of dynamic crosslinks, enabling them to behave as both robust networks and moldable plastics. Although their potential utility is significant, the growth of covalent adaptable networks (CANs) has obscured the line between "thermoplastic" and "thermoset" and erected a conceptual barrier to the growing number of new researchers entering this discipline.