Anti-Microbial, Thermal, Mechanical, and Gas Barrier Properties of Linear Low-Density Polyethylene Extrusion Blow-Molded Bottles.

Microbial contamination can occur on the surfaces of blow-molded bottles, necessitating the development and application of effective anti-microbial treatments to mitigate the hazards associated with microbial growth. In this study, new methods of incorporating anti-microbial particles into linear low-density polyethylene (LLDPE) extrusion blow-molded bottles were developed. The anti-microbial particles were thermally embossed on the external surface of the bottle through two particle deposition approaches (spray and powder) over the mold cavity.

Two-photon microscopy as a visual tool for polymer compatibilization monitoring: the PE-EVOH case.

In this study, we present two-photon microscopy (2PM) as an original technique to investigate the compatibilization between PE-HEMA and EVOH at the sub-micrometer level, both on the surface and in the bulk. 2PM is a nonlinear fluorescence imaging technique commonly exploited for thick biological tissue analysis. Here, we use 2PM to visualize polymer blending through 3D images of the obtained films.

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging.

The design and synthesis of a synthetic system that aims for the direct visualization of a synthetic rotary motor at the single molecule level on surfaces are demonstrated. This work requires careful design, considerable synthetic effort, and proper analysis. The rotary motion of the molecular motor in solution is shown by H NMR and UV-vis absorption spectroscopy techniques.

Velcrand Functionalized Polyethylene.

Velcrands are a specific class of cavitands whose complementary surfaces induce self-dimerization. The insertion of a velcrand as physical cross-linking unit into a polymer is reported. To this purpose, the velcrand was functionalized at the lower rim with an isocyanate group.

Design, Synthesis, and Isomerization Studies of Light-Driven Molecular Motors for Single Molecular Imaging.

The design of a multicomponent system that aims at the direct visualization of a synthetic rotary motor at the single molecule level on surfaces is presented. The synthesis of two functional motors enabling photochemical rotation and fluorescent detection is described. The light-driven molecular motor is found to operate in the presence of a fluorescent tag if a rigid long rod (32 Å) is installed between both photoactive moieties.

An ultrafast surface-bound photo-active molecular motor.

We report the synthesis and surface attachment of an ultrafast light-driven rotary molecular motor. Transient absorption spectroscopy revealed that the half-life of the rate determining thermal step of the rotary cycle in solution is 38 ± 1 ns, the shortest yet observed, making this the fastest molecular motor reported. Incorporation of acetylene legs into the structure allowed the motors to be grafted to azide-modified quartz and silicon substrates using the "click" 1,3-dipolar cycloaddition reaction.

Inherently chiral phosphonatocavitands as artificial chemo- and enantio-selective receptors of natural ammoniums.

Inherently chiral phosphonatocavitands with various bridging moieties at their wide rim were synthesized. Optical resolution by chiral HPLC was performed with cavitand 8 to afford enantiopure compounds (+)-8 and (-)-8. The molecular structures of hosts 8 and 12 were determined by X-ray diffraction.

Restricted guest tumbling in phosphorylated self-assembled capsules.

ABii diphosphonatocavitands self-assemble in chloroform solution to form dimeric molecular capsules. The molecular capsules can incarcerate an N-methylpyridinium or N-methylpicolinium guest. We have demonstrated that the supramolecular assembly acts as a molecular rotor as a result of the restricted motion of the guest inside the molecular cavity.

Resolution of the first nonracemic diquats.

Three tricyclic diquats with an eight-membered ring were prepared and shown to be the first configurationally stable derivatives of their kind. Resolution was achieved by using chiral hexacoordinated phosphorus BINPHAT and TRISPHAT anions. The diquat cations were obtained in high diastereo- and enantiomeric purity (ee>96% in most cases).

On the enantioselective olefin epoxidation by doubly bridged biphenyl azepine derivatives--mixed tropos/atropos chiral biaryls.

Diastereomeric doubly bridged biphenyl azepines, atropos at 20 degrees C and tropos at 80 degrees C, are precursors to effective iminium organocatalysts that are employed in the enantioselective epoxidation of prochiral olefins (up to 85% ee).

Biphasic enantioselective olefin epoxidation using Tropos dibenzoazepinium catalysts.

Several novel chiral iminium TRISPHAT [tris(tetrachlorobenzenediolato)phosphate(V)] salts combining a diphenylazepinium core, chiral exocyclic appendages, and lipophilic counterions have been prepared and tested in biphasic enantioselective olefin epoxidation conditions. Interestingly, the iminium salts derived from commercially available (S)- or (R)-1,2,2-trimethylpropylamine can display efficiency similar to those made from L-acetonamine. Variable-temperature NMR spectroscopy (VT-NMR) and circular dichroism (CD) experiments were performed in search of a correlation between good enantioselectivity in the products and high diastereomeric control of the biphenyl axial chirality of the catalysts.

Vibrational and electronic circular dichroism of delta-TRISPHAT [tris(tetrachlorobenzenediolato)phosphate(V)] anion.

Herein is reported an experimental and theoretical study of the circular dichroism properties of TRISPHAT (1) anion. ECD analysis of the [tetramethylammonium][delta-1] salt confirms the absolute configuration assignment obtained through X-ray crystallographic analysis of the parent cinchonidium salt. The structure, infrared, and vibrational circular dichroism (VCD) spectra derived from density functional theory (DFT) calculations are compared with experimental data.