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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Problems involved in simulating the flash carbonization process

Lee, Ching Yuan. January 1987 (has links)
Thesis (M.S.)--Ohio University, August, 1987. / Title from PDF t.p.
12

The electronic properties of granular and amorphous materials

Dawson, Janet Caroline January 1993 (has links)
No description available.
13

Electron microscopy techniques to further the understanding of conductive polymer composites

Burden, Adrian Paul January 1996 (has links)
No description available.
14

Recovery and evaluation of the solid products produced by thermocatalytic decomposition of tire rubber compounds

Liang, Lan 25 April 2007 (has links)
A thermal catalytic decomposition process has been developed to recycle used tire rubber. This process enables the recovery of useful products, such as hydrocarbons and carbon blacks. During the catalytic decomposition process, the tire rubber is decomposed into smaller hydrocarbons, which are collected in the process. The solid reaction residue, which normally consists of carbon black, catalysts, other inorganic rubber compound components, and organic carbonaceous deposits, was subjected to a series of treatments with the intention to recover the valuable carbon black and catalyst. The process economics depend strongly on the commercial value of the recovered carbon black and the ability to recover and recycle the catalysts used in the process. Some of the important properties of the recovered carbon black product have been characterized and compared with that of commercial-grade carbon blacks. The composition of the recovered carbon black was analyzed by TGA and EDX, the structure and morphology were studied through transmission electron microscopy (TEM), and the specific surface area was measured by BET nitrogen adsorption. The recovered products possess qualities at least comparable to (or even better than) that of the commercial-grade carbon black N660. Methods for increasing the market value of this recovered carbon black product are discussed. Anhydrous aluminum chloride (AlCl3) was used as the primary catalyst in the process. A catalyst recovery method based on the AlCl3 sublimation and recondensation was studied and found to be non-feasible. It is believed that the catalyst forms an organometallic complex with the decomposed hydrocarbons, such that it becomes chemically bonded to the residue material and hence not removable by evaporation. A scheme for the further study of the catalyst recovery is suggested.
15

Novel Porous Polyimide Film Doped with Carbon Black for Volatile Organic Compounds Detection

Ku, Yi-hang 17 June 2011 (has links)
This study developed an inexpensive and simple microsensor for detecting volatile organic compounds (VOCs). This developed VOC sensor is composed of a nano-porous polyimide (PI) film doped with carbon black (CB) as the sensing material. The conductivity of the PI/CB film changed after absorbing VOC contents in the air. In general, solid state based VOC sensors which use metal oxide as the sensing materials have to work at a temperature of about 300¡V350¢J. Alternatively, this research developed a VOC sensor capable of sensing VOCs at room temperature, resulting in a sensor system of low energy consumption. A post pore opening procedure by plasma etching is used to enhance the response of the sensor film. SEM images confirm that the micro-pores interconnect with their neighboring pores and also open to the outside air. The film prepared with pore opening procedure exhibit a response of 3 times faster than the film prepared without pore opening. Results indicate that the developed VOC sensor has a good repeatability for detecting VOCs. PI film with 1% (weight percent) of CB has the best sensitivity due to the well dispersion of CB. This research detected 100 ppm ethanol fifth times to show good reproducibility, and detected 10 ppm, 100 ppm, 1000 ppm benzene and ethanol for 24 hours to show long-term stability, and detected 101 ppm¡ã105 ppm widely VOCs concentration. Besides, this sensor has selectivity on specific gas like alcohol and aldehyde, the sensor material has special chemical bond that can connect with specific gas. Moreover, the sensitivity is about 155% at 25 oC and 80% at 60 oC, it is almost 2 times at 25 oC. The moisture can also be detected to avoid the impact on the sensor performance for detecting VOCs, the moisture capacitance changes is 16 times higher than VOCs. The sensor developed in this study provides a simple and straight forward method to fabricate low-cost VOC sensors.
16

Characterization of Carbon Black Surface Energy by IGC/TPD Method.

Chen, Ke-Cheng 16 July 2002 (has links)
none
17

Recovery and evaluation of the solid products produced by thermocatalytic decomposition of tire rubber compounds

Liang, Lan 25 April 2007 (has links)
A thermal catalytic decomposition process has been developed to recycle used tire rubber. This process enables the recovery of useful products, such as hydrocarbons and carbon blacks. During the catalytic decomposition process, the tire rubber is decomposed into smaller hydrocarbons, which are collected in the process. The solid reaction residue, which normally consists of carbon black, catalysts, other inorganic rubber compound components, and organic carbonaceous deposits, was subjected to a series of treatments with the intention to recover the valuable carbon black and catalyst. The process economics depend strongly on the commercial value of the recovered carbon black and the ability to recover and recycle the catalysts used in the process. Some of the important properties of the recovered carbon black product have been characterized and compared with that of commercial-grade carbon blacks. The composition of the recovered carbon black was analyzed by TGA and EDX, the structure and morphology were studied through transmission electron microscopy (TEM), and the specific surface area was measured by BET nitrogen adsorption. The recovered products possess qualities at least comparable to (or even better than) that of the commercial-grade carbon black N660. Methods for increasing the market value of this recovered carbon black product are discussed. Anhydrous aluminum chloride (AlCl3) was used as the primary catalyst in the process. A catalyst recovery method based on the AlCl3 sublimation and recondensation was studied and found to be non-feasible. It is believed that the catalyst forms an organometallic complex with the decomposed hydrocarbons, such that it becomes chemically bonded to the residue material and hence not removable by evaporation. A scheme for the further study of the catalyst recovery is suggested.
18

The effect of flow on carbon black and carbon nanotube suspensions

Yearsley, Kathryn Margaret January 2012 (has links)
No description available.
19

Positron annihilation spectroscopy study of rubber-carbon black composites

Jobando, Vincent Okello. January 2006 (has links) (PDF)
Thesis (Ph.D.)--Texas Christian University, 2006. / Title from dissertation title page (viewed Jan. 5, 2007). Includes abstract. Includes bibliographical references.
20

Structure-property relationships in polyurethane-carbon particle nanocomposites

Jirakittidul, Kittimon January 2013 (has links)
In this research work, the relationships between structure and properties in micro-composites and nano-composites of polyurethane (PU) and conductive carbon particles have been studied. PU is a class of block copolymers containing the urethane linkage (-NHCO-O-) within its structure. Most PU block copolymers consist of alternating ‘soft’ and ‘hard’ segments. The hard segment used in this study was based on 4,4’-methylenebisphenylisocyanate (MDI) and 2-methyl 1,3 propanediol (MP-Diol) which produced a stiff aromatic polyurethane. Two soft segments; poly(tetrahydofuran) (PTHF) and poly(propylene oxide) based polyol end-capped with ethylene oxide (PPO-EO) were used to study the effects of soft segment structure on PU properties. DMTA, DSC and modulated-DSC indicated that PU-PTHF had higher microphase separation due to greater immiscibility between PTHF and the MDI/MP-Diol hard segments. In order to improve the electrical and mechanical properties of PU, conductive carbon particles were incorporated. The critical factor was the dispersion of these conductive fillers in the PU matrix to obtain optimum properties. The first carbon filler studied was carbon black (CB). PU composites prepared by the adding of MP-Diol plus ultrasonication (MU) gave the best dispersion of CB aggregates resulting in higher thermal decomposition temperature and good conductivity. However, the mechanical toughness was reduced. In subsequent studies, PU composites incorporating three different treated multiwalled carbon nanotubes (MWCNT) were investigated. MWCNT were disentangled and shortened by ultrasonication and acid cutting treatments. The ultrasonicated MWCNT (MWCNT_U) had longer length than the acid-cut MWCNT (MWCNT_AC). Ultrasonication was the best technique for dispersing MWCNT since the storage modulus was increased by ~200% at low MWCNT_U loading and the toughness remained the same as unfilled PU. PU/MWCNT_AC nanocomposites at 1 – 3 wt% of MWCNT_AC exhibited similar electrical conductivities to unfilled PU at an order of 10-8 S/cm, implying that the acid cutting treatment might disturb the inherent conductivity in MWCNT. The conductive percolation thresholds of composites were determined following the percolation theory. It was found that the percolation thresholds for MWCNT-filled composites were significantly lower than that of CB-filled composites. The lowest percolation threshold was observed in MWCNT_U-filled composite at 0.31 wt%.

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