United States of America As Represented by the Administrator of Nasa

The United States of America As Represented by the Administrator of the

Mitsubishi Chemical America, Inc.

Dennis C Working

Emilie J Siochi

Cheol Park

John W Connell

Terry L St Clair

Joycelyn S Harrison

Jae-Woo Kim

Russell A Wincheski

Yi Lin

Kristopher E Wise

Catharine C Fay

Rudolf E Cais

William F Niederstadt

Robert G Bryant

Guerry Leonard Grune

Peter T Lillehei

Keith L Gordon

Russell W Smith

Santanu Debnath

A method allows for preparation of CNT nanocomposites having improved mechanical, electrical and thermal properties. Structured carbon nanotube forms such as sheet, yarn, and tape are modified with &#x3c0;-conjugated conductive polymers, including polyaniline (PANT), fabricated by in-situ polymerization. The PANI modified CNT nanocomposites are subsequently post-processed to improve mechanical properties by hot press and carbonization.

Polyaniline/carbon nanotube sheet nanocomposites

One aspect of the present invention is a puncture healing polymer blend comprising a self-healing first polymer material having sufficient melt elasticity to snap back and close a hole formed by a projectile passing through the material at a velocity sufficient to produce a local melt state in the first polymer material. The puncture healing polymer blend further includes a non-self-healing second material that is blended with the first polymer material. The blend of self-healing first polymer material and second material is capable of self-healing, and may have improved material properties relative to known self-healing polymers.

Puncture healing engineered polymer blends

A method allows for preparation of CNT nanocomposites having improved mechanical, electrical and thermal properties. Structured carbon nanotube forms such as sheet, yarn, and tape are modified with &#x3c0;-conjugated conductive polymers, including polyaniline (PANI), fabricated by in-situ polymerization. The PANI modified CNT nanocomposites are subsequently post-processed to improve mechanical properties by hot press and carbonization.

Conventional toughening agents are typically rubbery materials or small molecular weight molecules, which mostly sacrifice the intrinsic properties of a matrix such as modulus, strength, and thermal stability as side effects. On the other hand, high modulus inclusions tend to reinforce elastic modulus very efficiently, but not the strength very well. For example, mechanical reinforcement with inorganic inclusions often degrades the composite toughness, encountering a frequent catastrophic brittle failure triggered by minute chips and cracks. Thus, toughening generally conflicts with mechanical reinforcement. Carbon nanotubes have been used as efficient reinforcing agents in various applications due to their combination of extraordinary mechanical, electrical, and thermal properties. Moreover, nanotubes can elongate more than 20% without yielding or breaking, and absorb significant amounts of energy during deformation, which enables them to also be an efficient toughening agent, as well as excellent reinforcing inclusion. Accordingly, an improved toughening method is provided by incorporating nanotubular inclusions into a host matrix, such as thermoset and thermoplastic polymers or ceramics without detrimental effects on the intrinsic physical properties of the matrix.

Nanotubular toughening inclusions

Conventional toughening agents are typically rubbery materials or small molecular weight molecules, which mostly sacrifice the intrinsic properties of a matrix such as modulus, strength, and thermal stability as side effects. On the other hand, high modulus inclusions tend to reinforce elastic modulus very efficiently, but not the strength very well. For example, mechanical reinforcement with inorganic inclusions often degrades the composite toughness, encountering a frequent catastrophic brittle failure triggered by minute chips and cracks. Thus, toughening generally conflicts with mechanical reinforcement. Carbon nanotubes have been used as efficient reinforcing agents in various applications due to their combination of extraordinary mechanical, electrical, and thermal properties. Moreover, nanotubes can elongate more than 20% without yielding or breaking, and absorb significant amounts of energy during deformation, which enables them to also be an efficient toughening agent, as well as excellent reinforcing inclusion. Accordingly, an improved toughening method is provided by incorporating nanotubular inclusions into a host matrix, such as thermoset and thermoplastic polymers or ceramics without detrimental effects on the matrix's intrinsic physical properties.

A nanocomposite structure and method of fabricating same are provided. The nanocomposite structure is a polymer in an extruded shape with carbon nanotubes (CNTs) longitudinally disposed and dispersed in the extruded shape along a dimension thereof. The polymer is characteristically defined as having a viscosity of at least approximately 100,000 poise at a temperature of 200&#xb0; C.

Mechanically strong, thermally stable, and electrically conductive nanocomposite structure and method of fabricating same

A fluid-control electro-active device includes a piezo-diaphragm made from a ferroelectric material sandwiched by first and second electrode patterns configured to introduce an electric field into the ferroelectric material when voltage is applied thereto. The electric field originates at a region of the ferroelectric material between the first and second electrode patterns, and extends radially outward from this region of the ferroelectric material and substantially parallel to the plane of the ferroelectric material. The piezo-diaphragm deflects symmetrically about this region in a direction substantially perpendicular to the electric field. An annular region coupled to and extending radially outward from the piezo-diaphragm perimetrically borders the piezo-diaphragm. A housing is connected to the annular region and defines at least one fluid flow path therethrough with the piezo-diaphragm disposed therein.

Electro-active device using radial electric field piezo-diaphragm for control of fluid movement

A photosensitive drum is provided with an insert by injecting a rapidly curing material directly into the drum such that when the material cures, a noise/vibration reducing insert is provided. The insert material can be injected by a reciprocating nozzle during the manufacture/assembly of the drum. By injecting the insert material into the drum when the drum is being manufactured/assembled, it is not necessary to separately design the insert or to procure tooling to separately manufacture the insert. In addition, the insert will closely conform to the interior of the drum since the insert is molded inside of the drum. In addition, modifications to the insert (e.g., to vary the mass or size of the insert) are readily achievable without tooling modifications.

Photosensitive drum having injection molded insert and method of forming same

A device and method for reducing noise and/or vibration in an image forming apparatus. In a preferred form, an insert is disposed inside of a photosensitive drum, and the insert is a hollow tubular member including first and second members having surfaces oblique with respect to a longitudinal axis of the photosensitive drum, wherein the surfaces each face each other. The first and second members are moved relative to each other in order to change the overall diameter of the insert, such that upon insertion, the overall diameter can be made smaller than the inner diameter of the drum, and after insertion, the overall diameter of the insert can be increased such that the outer surface of the insert comes into contact with an inner surface of the drum. As such, the insert can be anchored to the interior of the drum without using adhesive and can be easily removed for recycling purposes.

Noise reducing device for photosensitive drum of an image forming

A device and method for reducing noise and/or vibration in an image forming apparatus. In a preferred form, an insert is disposed inside of a photosensitive drum, and the insert is a hollow tubular member having at least one slot extending through the tubular member so that the tubular member is resilient in a radial direction. The slot can be, for example, helical, so that the insert is a helical coil, with an outer diameter of the helical coil (in an uncompressed state) larger than an inner diameter of the photosensitive drum. The insert is radially compressed when it is inserted into the drum, so that the tendency of the insert to expand holds the insert in place within the drum. The insert reduces noise and vibration which can occur during operation of the photosensitive drum, and can also provide a supportive effect for the drum since the insert is urged in a radially outward direction against the inner surface of the drum.

A polyimide fiber having textile physical property characteristics and the process of melt extruding same from a polyimide powder. Polyimide powder formed as the reaction product of the monomers 3,4'-ODA and ODPA, and endcapped with phthalic anhydride to control the molecular weight thereof, is melt extruded in the temperature range of 340.degree. C. to 360.degree. C. and at heights of 100.5 inches, 209 inches and 364.5 inches. The fibers obtained have a diameter in the range of 0.0068 inch to 0.0147 inch; a mean tensile strength in the range of 15.6 to 23.1 ksi; a mean modulus of 406 to 465 ksi; and a mean elongation in the range of 14 to 103%.

Polyimide fibers

A method and apparatus uniformly impregnate stranded material with dry powder such as low solubility, high melt flow polymer powder to produce, for example, composite prepregs. The stranded material is expanded in an impregnation chamber by an influx of air so that the powder, which may enter through the same inlet as the air, penetrates to the center of the stranded material. The stranded material then is contracted for holding the powder therein. The stranded material and powder may be pulled through the impregnation chamber in the same direction by vacuum. Larger particles of powder which do not fully penetrate the stranded material may be combed into the stranded material and powder which does not impregnate the stranded material may be collected and reused.

Growing community of inventors

Norfolk, VA, United States of America

Dennis C Working