Temple University

Mortimer M Labes

John H MacMillan

J H Chen

Jiann H Chen

Marvin E Jones

Beverly D Bostwick

Peter Love

Huey-Chuen I Kao

Ranganath Parthasarathy

Heewon Lee

A method of making and using a liquid crystal cumulative dosimeter container including a resilient outer body sealed to confine a first liquid crystal composition constituent and a second liquid crystal composition constituent and having at least one transparent section to permit observation of the color of the confined composition, and a barrier contained completely within and physically unattached to the outer body for separating the first constituent from the second constituent, whereby disruption of the barrier allows the first constituent to mix with the seocnd constituent. The barrier is formed either by encapsulating one or both of the constituents or by using air bubbles.

Method of making and using an improved liquid crystal cumulative

Electrically conductive carbon flakes and films are prepared in high yield by the pyrolysis of cyclic aromatic hydrocarbons, optionally halogenated, in the presence of a dehydrogenating agent at about at least 800.degree. C. Flakes of thicknesses up to 20 .mu.m and lengths up to 1 cm on a side are metal-like in appearance and have a conductivity of about 200-300 S/cm at room temperature. By heat treatment to 2600.degree. C., graphitic order is improved and the conductivity rises to .apprxeq.10000-15000 S/cm.

Process for production of graphite flakes and films via low temperature

A container for a liquid crystal cumulative dosimeter including a resilient outer body sealed to confine a first liquid crystal composition constituent and a second liquid crystal composition constituent and having at least one transparent section to permit observation of the color of the confined composition, and a barrier contained completely within and physically unattached to the outer body for separating the first constituent from the second constituent, whereby disruption of the barrier allows the first constituent to mix with the second constituent. The barrier is formed either by encapsulating one or both of the constituents or by using air bubbles. Methods of manufacturing the various containers shown and processes of using those containers are also disclosed.

Container for liquid crystal cumulative dosimeter

A tamper evident over-wrap is disclosed which employs a multi-layered system including three overlapping layers of containment material and two interleaved layers of reactive material, at least one of which is a gel. Upon formation of an opening of the middle layer of containment material, the previously-isolated layers of reactive material will intermingle and react. These materials react to form a color change. By using a gel, manifestations of tampering attempts are considerably enhanced.

Gel-interleaved tamper-evident wrap

Carbon-transition metal composite formed via pyrolytic decomposition of a polycyanogen in the presence of a transition metal or a salt thereof.

Transition-metal-carbon composites and methods for making

An electro- and magneto-optic device which comprises a fluid suspension of anisotropic platelets in a dielectric media, and a means for imposing an electrical or magnetic field on the suspension. Orientation of such platelets in the media is accomplished by imposition of an electrical or magnetic field. The invention may be used to provide an information display or a field controlled shutter in window glass.

Electro- and magneto-optic devices

A novel polycyanogen (MW at least 500) is made by electrochemical polymerization of cyanogen in solution. Fiber and pyrolyzed forms of this polymer and methods of making same are also described.

Cyanogen polymers and pyropolymers and fibers thereof

A low viscosity, short pitch, cholesteric liquid crystal composition consisting of an alkali cromoglycate dissolved in water or water with a polar solvent, together with an optically active solute in sufficient concentration to render the cromoglycate cholesteric. Suitable compositions will reflect light in the visible spectrum and may be magnetically, electrically, or thermally addressed to produce optical effects therein.

Low viscosity lyotropic cholesteric liquid crystal compositions

A group of novel, low temperature liquid crystalline compounds with terminal, primary or secondary amino polar electron donating groups are disclosed. These include, for example, p-alkyl-or alkoxy-phenylcyclohexanes, bicyclohexyls or biphenyl ring systems, substituted at the p' position with alkyl primary or secondary amines, of which one example is p-(4-trans-n-pentylcyclohexyl)benzylamine.

Amine-substituted liquid crystal compositions

An electrolytic cell wherein one of the elements is comprised of a canal clathrate complex of benzophenone and a polyiodide salt of a cation from a group consisting of potassium (K.sup.+), sodium (Na.sup.+), cesium (Cs.sup.+), lithium (Li.sup.+), ammonium (NH.sub.4.sup.+), rubidium (Rb.sup.+) and tetraalkylammonium (R.sub.4 N.sup.+ where R is an alkyl group of less than five carbons). This complex functions through its tunnel-like dispositions of the cations, having certain unfilled sites and certain other sites occupied by the CHCl.sub.3 molecule, as a solid fast ion conductor. The same composition, again apparently because of the canal clathrate complex crystal structure, is adapted, by virtue of its electronic conductivity to function as an electrode in an electrolytic cell.

Canal clathrate complex solid electrolyte cell

A liquid crystal composition for improved electro-optic displays. The composition undergoes an electrically induced cholesteric-nematic phase transition and includes fluorescent materials which are excited by ultra-violet radiation. In the cholesteric phase of the composition, the fluorescence is much stronger producing sufficient contrast to render the display visible in the dark.

Fluorescent liquid crystal display

Irradiation of collected S.sub.4 N.sub.4 decomposition products with light or radiation in the .gamma. to visible range enhances the initiation of polymerization of the decomposition products to produce polysulfur nitride, which is typically conductive and usually referred to as (SN).sub.x. Irradiation of a masked coating of collected S.sub.4 N.sub.4 decomposition products and completion of polymerization thereof and removal of non-irradiated, non-polymerized portions thereof will result in an electrically conductive coating disposed in a preselected pattern. S.sub.4 N.sub.4 decomposition products may also be dispersed in a matrix, e.g. a photographic emulsion which is transparent or partially transparent to light, or which may be rendered partially or selectively transparent or opaque. This might be useful, for example, for imaging applications, or for producing a selectively transparent pattern for subsequent photoinduced initiation of polymerization of the S.sub.4 N.sub.4 products.

Method for making polysulfur nitride and product thereof

Liquid crystal mixtutre of donor and acceptor molecules, the first consisting of a liquid crystal compound having an unshared electron pair (the donor) and the second generally consisting of an electron receptive compound such as a p-cyano-p'-alkyl- or alkoxy-substituted bipheny liquid crystal compound (the acceptor); together these compounds form a molecular complex with improved physical properties, including particularly a broader mesophasic temperature range, then would be expected from a simple combination of such liquid crystals.

Liquid crystal compositions

Cumulative temperature dosimeter utilizes a temperature dependent reaction in a cholesteric liquid crystal composition to produce a color change indicative of temperature exposure over a period of time. Typically, the composition includes, as a solvent, a cholesteric liquid crystal, such as a mixture of p-methoxy-p'-n-butyl-azoxybenzene, cholesteryl nonanoate, cholestyl chloride, and cholesteryl oleyl carbonate. One or more solutes are included, the solutes being reactive at a rate which is temperature dependent, to cause either generation or consumption of mesogenic compounds. In turn, the pitch of the solvent, observable as a visible color change, is affected in proportion to the cumulative temperature exposure of the composition.

Liquid crystal cumulative dosimeter

Using a standardized cell containing a thin layer of an aligned nematic liquid crystalline material, a relationship is determined between concentration of an optically active solute material in the liquid crystal layer and line spacing in a pattern produced by differential light refraction, upon the injection of different amounts of the optically active compound. Subsequently, quantitative analysis of a sample containing the optically active compound is accomplished by injecting a known amount of the sample into a second identical standardized cell, observing the line spacing of refracted light in the second cell and comparing it to the relationship determined in the first cell. Optically active compounds analyzable in this manner include steroids and cholesteryl esters. A preferred nematic liquid crystalline material is n-p-methoxybenzylidene-p-n-butylaniline. A specific system described consists of cholesteryl-2-methyl valerate in homeotropically aligned n-p-methoxybenzylidene-p-n butylaniline with a layer thickness in the cell of 12.7 microns.

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Philadelphia, PA, United States of America

Mortimer M Labes