263 results about "Porous anodic aluminum oxide" patented technology

The presently disclosed invention provides for the fabrication of porous anodic alumina (PAA) films on a wide variety of substrates. The substrate comprises a wafer layer and may further include an adhesion layer deposited on the wafer layer. An anodic alumina template is formed on the substrate. When a rigid substrate such as Si is used, the resulting anodic alumina film is more tractable, easily grown on extensive areas in a uniform manner, and manipulated without danger of cracking. The substrate can be manipulated to obtain free-standing alumina templates of high optical quality and substantially flat surfaces PAA films can also be grown this way on patterned and non-planar surfaces. Furthermore, under certain conditions the resulting PAA is missing the barrier layer (partially or completely) and the bottom of the pores can be readily accessed electrically. The resultant film can be used as a template for forming an array of nanowires wherein the nanowires are deposited electrochemically into the pores of the template. By patterning the electrically conducting adhesion layer, pores in different areas of the template can be addressed independently, and can be filled electrochemically by different materials. Single-stage and multi-stage nanowire-based thermoelectric devices, consisting of both n-type and p-type nanowires, can be assembled on a silicon substrate by this method.

In one embodiment, SWNTs are synthesized from an embedded catalyst in a modified porous anodic alumina (PAA) template. Pd is electrodeposited into the template to form nanowires that grow from an underlying conductive layer beneath the PAA and extend to the initiation sites of the SWNTs within each pore. Individual vertical channels of SWNTs are created, each with a vertical Pd nanowire back contact. Further Pd deposition results in annular Pd nanoparticles that form on portions of SWNTs extending onto the PAA surface. Two-terminal electrical characteristics produce linear I-V relationships, indicating ohmic contact in the devices.

The present invention discloses one kind of ordered porous anode oxidized alumina template preparing process. Compared with available technology, the said process has the advantages of capacity one preparing great area highly ordered nanometer template, high template success rate and high template quality including raised nanometer pore arrangement orderliness, pore size homogeneity, depth uniformity and porosity.

A modified porous anodic alumina template (PAA) containing a thin CNT catalyst layer directly embedded into the pore walls. CNT synthesis using the template selectively catalyzes SWNTs and DWNTs from the embedded catalyst layer to the top PAA surface, creating a vertical CNT channel within the pores. Subsequent processing allows for easy contact metallization and adaptable functionalization of the CNTs and template for a myriad of applications.

Methods and apparatus for an electronic device such as a field effect transistor. One embodiment includes fabrication of an FET utilizing single walled carbon nanotubes as the semiconducting material. In one embodiment, the FETs are vertical arrangements of SWCNTs, and in some embodiments prepared within porous anodic alumina (PAA). Various embodiments pertain to different methods for fabricating the drains, sources, and gates.

The presently disclosed invention provides for the fabrication of porous anodic alumina (PAA) films on a wide variety of substrates. The substrate comprises a wafer layer and may further include an adhesion layer deposited on the wafer layer. An anodic alumina template is formed on the substrate. When a rigid substrate such as Si is used, the resulting anodic alumina film is more tractable, easily grown on extensive areas in a uniform manner, and manipulated without danger of cracking. The substrate can be manipulated to obtain free-standing alumina templates of high optical quality and substantially flat surfaces PAA films can also be grown this way on patterned and non-planar surfaces. Furthermore, under certain conditions the resulting PAA is missing the barrier layer (partially or completely) and the bottom of the pores can be readily accessed electrically. The resultant film can be used as a template for forming an array of nanowires wherein the nanowires are deposited electrochemically into the pores of the template. By patterning the electrically conducting adhesion layer, pores in different areas of the template can be addressed independently, and can be filled electrochemically by different materials. Single-stage and multi-stage nanowire-based thermoelectric devices, consisting of both n-type and p-type nanowires, can be assembled on a silicon substrate by this method

The invention discloses a method for quantitatively detecting telomerase activity based on a nano pore channel and electrochemical sensing.The method comprises the following steps that firstly, a telomerase recognition sequence is connected to the inner wall of a porous anodic alumina template or a polyethylene terephthalate film to serve as a primer; secondly, telomerase amplifies the primer to form a G-rich sequence; a G-quadruplex is formed in the presence of potassium ions; electrochemical detection is conducted on the current produced through indicating molecules of the nano pore channel by utilizing an electrochemical workstation.The method does not need complex material preparation and DNA probe marking, and can avoid the defects of high detection cost, complicated operation and poor reproducibility caused by the complex material preparation and DNA probe marking and has the advantages of being low in cost, quick, simple, convenient, high in sensitivity and good in accuracy.

The invention provides a method for preparing a tin-carbon / core-shell nano-particle fully filled carbon nano-tube composite anode material, which comprises the following steps: a porous anodic alumina film is placed in a stannic chloride water solution for soaking, is dried and then is subjected to chemical vapor deposition and reduction reaction in mixed gas of C2H2 and N2 at high temperature to obtain the tin-carbon / core-shell nano-particle fully filled carbon nano-tube composite anode material. The size and morphology of filled particles of the invention are controllable, the filling efficiency of the method is high, the structural purity of a target product can approach 100 percent, the interference of incomplete filling on the one-to-one correspondence of a structure and performance of the product is avoided, and the reversible lithium-storage capacity of the carbon nano-tube composite anode material with the novel structure can reach more than 700 mAh / g.

The invention discloses a self-assembly preparation method and application of a solid / liquid interface of graphene oxide hydrogel. The method comprises the following steps of: preparing graphite oxide powder and deionized water into a solution with the concentration of 1-7 mg / mL; and immersing a porous anodic alumina film or an aluminum sheet, an aluminum foil or a copper sheet treated by a mixed liquid of concentrated sulfuric acid and hydrogen peroxide in a water solution of graphene oxide at 0-80 DEG C to form graphene oxide hydrogel on the surface of the porous anodic alumina film, the aluminum sheet, the aluminum foil or the copper sheet. The graphene oxide hydrogel is used for preparing graphene oxide aerogel and graphene aerogel and is also a coating of the graphene oxide hydrogel. The preparation method provided by the invention is simple and does not require any high-temperature high-pressure process, and the water mass of the graphene oxide hydrogel is more than 99%.

The invention relates to an impressing hard template in a nanostructure, which belongs to the field of nano manufacturing and is characterized in that a porous template with a hard material substrate is prepared by the porous AAO (anodic aluminum oxide) membrane technology and can be directly used as an impressing (from top to bottom) template after the hard substrate is added and the surface modification treatment is carried out. A porous AAO membrane can self-organize and grow into an ordered six-site symmetrical porous structure, and steep holes are uniformly distributed. When the porous AAO membrane is used as the template, various nanostructures and devices with optical, electrical and magnetic properties can be prepared by a processing method of directional assembling from bottom to top such as thermal evaporation, sputtering, deposition and electrochemical assembling. As the hard material substrate is added and the surface modification treatment is carried out, the AAO template technology is transplanted into the field of top-to-bottom surface micro-structure processing. Compared with the present technical method of the common electron beam direct writing, the manufacturing method for the impressing hard template with a nano-grade high-density structure not only has the obvious characteristics of low cost, short period and simple processing, but also can be widely used in the processing as well as researching of the nano-grade high-density surface nanostructure and particularly has broad prospects in the fields of semiconductor lighting and high-density storage. Meanwhile, as the hard substrate is increased, the shortcomings of the present brittle and fragile AAO template are overcome, thereby being more beneficial for duplication of the soft template.

The invention relates to a method for preparing an ordered macroporous anodic alumina film by two-step anodic oxidation. The method comprises the following steps of: carrying out hard anodizing on aluminum which is subjected to high temperature annealing, ultrasound deoiling and electrochemical polishing treatments in modified oxalic acid electrolyte, so as to obtain a porous anodic alumina film; removing an irregular porous alumina layer which is formed after first anodic oxidation by using a mixed solution of chromic acid and phosphoric acid; then carrying out second anodic oxidation, namely carrying out mild anodic oxidation on the aluminum sheet with the alumina film removed in the modified phosphate electrolyte in a constant voltage manner, wherein the voltage in the second anodic oxidation is completely the same as the voltage in the first anodic oxidation; and finally chambering the test sample subjected to anodic oxidation in a phosphoric acid solution to obtain the ordered macroporous anodic alumina film. The preparation method is carried out under an ice-water bath condition without the requirement on a very low temperature or a high voltage; the cost of used raw materials is low; and equipment is simple and is convenient to operate and easy to control, and therefore the method has a bright application prospect in the modern industry and high and new technology field.

The invention provides a one-dimensional permanent magnetic nano-material, in which hard magnetic tubes are coated with soft magnetic wires and a preparation method thereof. The material has a composite structure that hard magnetic nano-tubes prepared from hard magnetic phase FePt or CoPt alloy are coated with soft magnetic nano-wires prepared from soft magnetic phase pure metals including Fe, Co and Ni or binary and ternary alloy, wherein, the diameter of the one-dimensional permanent magnetic nano-material is 10nm to 220nm; the diameter of the soft magnetic phase nano-wires is 4nm to 60nm; and the wall thickness of the hard magnetic phase nano-tubes is 3nm to 80nm. The preparation method of the material comprises the following steps: firstly, preparing the hard magnetic alloy nano-tubes in a porous anodic alumina template by using the template wetting method; and then, growing the soft magnetic nano-wires in the nano-tubes by using the electrochemical deposition method. The invention has the advantages that the size of the one-dimensional permanent magnetic nano-material is controllable and the preparation method is simple.