TUNING OF FE CATALYSTS FOR GROWTH OF SPIN-CAPABLE CARBON NANOTUBES

• Main Authors: LEE GIL SIK, OVERZET LAWRENCE J, LEE KYUNG HWAN, KIM JAE HAK
• Format: Patent
• Language: English
• Published: 14.04.2011
• Subjects: APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBONFILAMENTS; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; BASIC ELECTRIC ELEMENTS; CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS,THREADS, FIBRES, BRISTLES OR RIBBONS; CHEMISTRY; COMPOUNDS THEREOF; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INORGANIC CHEMISTRY; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; METALLURGY; NANOTECHNOLOGY; NATURAL OR ARTIFICIAL THREADS OR FIBRES; NON-METALLIC ELEMENTS; PERFORMING OPERATIONS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; SEMICONDUCTOR DEVICES; SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; SPINNING; SPRAYING OR ATOMISING IN GENERAL; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; TEXTILES; TRANSPORTING

Growing spin-capable multi-walled carbon nanotube (MWCNT) forests in a repeatable fashion will become possible through understanding the critical factors affecting the forest growth. Here we show that the spinning capability depends on the alignment of adjacent MWCNTs in the forest which in turn results from the synergistic combination of a high areal density of MWCNTs and short distance between the MWCNTs. This can be realized by starting with both the proper Fe nanoparticle size and density which strongly depend on the sheet resistance of the catalyst film. Simple measurement of the sheet resistance can allow one to reliably predict the growth of spin-capable forests. The properties of pulled MWCNTs sheets reflect that there is a relationship between their electrical resistance and optical transmittance. Overlaying either 3, 5, or 10 sheets pulled out from a single forest produces much more repeatable characteristics.