Enhancement in Electro-Optic Properties of Dynamic Scattering Systems through Addition of Dichroic Dyes

Electro-optic properties of dynamic scattering in homeotropically aligned pure and dichroic dye-doped nematic liquid crystal samples are examined. The optical properties of the two systems are quantified using transmission properties of scattered and unscattered as a function of amplitude and frequency of an applied voltage. Auto-correlation of the scattered signal at different applied voltages is used to compare the decay times in the two systems. Lastly, the histogram of the scattered signal reveals a wavevector dependent large light scattering event. The dye-doped system shows a significant enhancement of light blocking property in both normal and off-axis light propagation. The characteristics of the system are compared to other scattering technologies. The results suggest that dye-doped system can overcome shortcomings in scattering based devices used for near-eye applications

Modulating Photochemical Properties to Enhance the Stability of Electronically Dimmable Eye Protection Devices

The study evaluates compatibility of stabilizers with dye doped liquid crystal (LC) scaffolds that are used in electronically dimmable materials. The photodegradation of the materials was investigated and suitable stabilizers were evaluated to slow the degradation process. Various types of benzotriazole-based stabilizers were evaluated for stabilizing the liquid crystals. Based on spin trapping experiments, radicals generated upon UV exposure is likely responsible for the degradation of the system. The radical generation is competitively inhibited by the addition of stabilizers. Abbreviations: LC, liquid crystal; STB, stabilizers

Polymers responsive to radiation pressures

Polymers that undergo a reversible phase change in response to being exposed to a light from a laser having a radiation pressure greater than a threshold level. The phase changeable polymers have the ability to reduce the intensity of the laser and can advantageously scatter laser light incident on the polymers. The on-off response of such polymers is in the microsecond range and the light scattering property is independent of laser wavelength. The polymers can beneficially be incorporated into devices to protect human vision and optical instruments that are vulnerable to lasers at high intensities. Methods for making and using such devices are also disclosed.U

Polymers responsive to radiation pressures

Polymers that undergo a reversible phase change in response to being exposed to a light from a laser having a radiation pressure greater than a threshold level. The phase changeable polymers have the ability to reduce the intensity of the laser and can advantageously scatter laser light incident on the polymers. The on-off response of such polymers is in the microsecond range and the light scattering property is independent of laser wavelength. The polymers can beneficially be incorporated into devices to protect human vision and optical instruments that are vulnerable to lasers at high intensities. Methods for making and using such devices are also disclosed.U

Polymers responsive to radiation pressures

Polymers that undergo a reversible phase change in response to being exposed to a light from a laser having a radiation pressure greater than a threshold level. The phase changeable polymers have the ability to reduce the intensity of the laser and can advantageously scatter laser light incident on the polymers. The on-off response of such polymers is in the microsecond range and the light scattering property is independent of laser wavelength. The polymers can beneficially be incorporated into devices to protect human vision and optical instruments that are vulnerable to lasers at high intensities. Methods for making and using such devices are also disclosed.U

Determination of Membrane Immersion Depth with O2: A High-Pressure 19F NMR Study

AbstractOxygen is known to partition with an increasing concentration gradient toward the hydrophobic membrane interior. At partial pressures (PO2) of 100Atm or more, this concentration gradient is sufficient to induce paramagnetic effects that depend sensitively on membrane immersion depth. This effect is demonstrated for the fluorine nucleus by depth-dependent paramagnetic shifts and spin-lattice relaxation rates, using a fluorinated detergent, CF3(CF2)5C2H4-O-maltose (TFOM), reconstituted into a lipid bilayer model membrane system. To interpret the spin-lattice relaxation rates (R1P) in terms of a precise immersion depth, two specifically fluorinated cholesterol species (6-fluorocholesterol and 25-fluorocholesterol), whose membrane immersion depths were independently estimated, were studied by 19F NMR. The paramagnetic relaxation rates, R1P, of the cholesterol species were then used to parameterize a Gaussian profile that directly relates R1P to immersion depth z. This same Gaussian curve could then be used to determine the membrane immersion depth of all six fluorinated chain positions of TFOM and of two adjacent residues of specifically fluorinated analogs of the antibacterial peptide indolicidin. The potential of this method for determination of immersion depth and topology of membrane proteins is discussed