Photoconductivity of carbon aerogels

Hosoya, Masahiro; Reynolds, Gillian A. M.; Dresselhaus, M. S.; Pekala, R.W.

doi:10.1557/jmr.1993.0811

Cited by 17 publications

(5 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6,9 As mentioned earlier, the fluctuation-induced tunneling model was also shown to explain the conductivity of carbon-PVC. 6,9 As mentioned earlier, the fluctuation-induced tunneling model was also shown to explain the conductivity of carbon-PVC.…”

mentioning

confidence: 76%

Direct current electrical conductivity of Versicon™ blended in poly(vinyl chloride)

Speel

LeMaire

1997

J. Mater. Res.

View full text Add to dashboard Cite

The direct current (dc) electrical conductivity of the conducting polymer Versicon TM blended in poly(vinyl chloride) (PVC) was measured from 25 K to 310 K. The data were fitted to various electrical transport models, and the best fit was found with the fluctuation-induced tunneling model, suggesting that tunneling dominates in the mode of electron transport at low temperatures. The parameters, T 1 and T 0 from the fluctuation-induced tunneling model, were found to be 625 K and 129 K, respectively. The interparticle distance was estimated to be about 13Å. At higher temperatures, the plot of the log of resistivity versus the reciprocal of the temperature was linear, indicating that thermally activated hopping dominated the mode of electrical transport at these temperatures. The results support earlier findings that Versicon TM forms continuous aggregates in blends. The results also support growing evidence in the literature that these types of aggregate formation tend to strongly influence the mode of electrical transport in composites.Versicon TM , a product of Allied Signal Inc., is a polyaniline doped with an organic sulfonic acid. 1 When Versicon TM is dispersed in poly(vinyl chloride) (PVC) and other thermoplastics, it is reported to have a tendency to aggregate spontaneously to form conducting pathways throughout the system. The Versicon TM particles are spherical and range in size from 20 to 100 mm, but can be broken down into submicron particles in blends. 1 Work done in our laboratory confirmed that even pressed pellets of Versicon TM behaved like they consisted of aggregates of spherical particles. 2 Versicon TM in blends such as PVC is reported to be useful for electrical shielding and other specific applications such as for loadings in conductive paints. 1 This study is to explore the mode of electrical transport in Versicon TM in blends with highly resistive media such as PVC.Blends of 10%, 20%, and 30% Versicon TM in PVC were supplied by Americhem in the form of grains about two millimeters in size. The samples were heat pressed at about 200 ± C. Only the 30% Versicon TM blend was used in our measurements since the 20% and 10% samples were practically insulators. A sample of the 30% Versicon TM blend was cut into a parallelepiped (14.6 3 2.1 3 1.0 mm) for the resistivity measurements. The four lead method was used in the I-V measurements. Silver paint was used to attach leads to the sample. The data acquisition system consisted of Keithley Model 196 Digital Multimeter, a Keithley a) Author to whom all correspondence should be addressed.Model 220 Current Source, a Keithley Model 705 Scanner to allow the sample circuits and a test circuit to be opened and closed, a Lake Shore Cryotronics Model 330 Autotuning Temperature Controller which sets and reads the temperature at the sample site, and a CTI-Cryogenices 22C/350C Cryodyne © closed cycle helium refrigerator from Janis Research. An IEEE 488 interface from Capital Equipment Corporation enabled these devices to be controlled and the data to be collecte...

show abstract

mentioning

confidence: 76%

Direct current electrical conductivity of Versicon™ blended in poly(vinyl chloride)

Speel

LeMaire

1997

J. Mater. Res.

View full text Add to dashboard Cite

show abstract

“…CA are highly cross-linked nanosized porous materials. Being light weight, mesoporous and conductive with a large surface area, CA are being employed in different fields, including supercapacitors, advanced catalyst supports, absorbents, rechargeable batteries, environmental protection and chromatographic packing [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. CA are formed by pyrolysis of organic aerogels at temperatures of 800–900 °C [ 27 ].…”

Section: Introductionmentioning

confidence: 99%

H2S-Sensing Studies Using Interdigitated Electrode with Spin-Coated Carbon Aerogel-Polyaniline Composites

et al. 2021

View full text Add to dashboard Cite

In this paper, carbon aerogel (CA)-polyaniline (PANI) composites were prepared and first applied in the study of H2S gas sensing. Here, 1 and 3 wt% of as-obtained CA powder were blended with PANI to produce composites, which are denoted by PANI-CA-1 and PANI-CA-3, respectively. For the H2S gas-sensing studies, the interdigitated electrode (IDE) was spin-coated by performing PANI and PANI-CA composite dispersion. The H2S gas-sensing properties were studied in terms of the sensor’s sensitivity, selectivity and repeatability. IDE coated with PANI-CA composites, as compared with pristine PANI, achieved higher sensor sensitivity, higher selectivity and good repeatability. Moreover, composites that contain higher loading of CA (e.g., 3 wt%) perform better than composites with lower loading of CA. At 1 ppm, PANI-CA-3 displayed increased sensitivity of 452% at relative humidity of 60% with a fast average response time of 1 s compared to PANI.

show abstract

“…These properties are derived from the aerogel microstructure which is a network of interconnected primary particles. Owing to their unique textural properties carbon aerogels are considered to be suitable as electrode materials for supercapacitors and rechargeable batteries, advanced catalyst supports, adsorbents and chromatographic packing [10][11][12][13][14][15][16][17] .…”

Section: Introductionmentioning

confidence: 99%

Rapid Fabrication of Monolithic Carbon Aerogels Based on Resorcinol-Formaldehyde by Ambient Pressure Drying

Park¹,

Kim²,

Oh³

et al. 2013

Asian J. Chem.

View full text Add to dashboard Cite

New synthesis conditions to rapidly fabricate monolithic carbon aerogels based on resorcinol and formaldehyde were developed using ambient pressure drying. The resorcinol-formaldehyde aerogel network synthesized under strong basic conditions not only dramatically reduced the gelation time but also exhibited better particle connectivity. This also allowed for the rapid drying of the wet-gels and subsequent carbonization in an inert atmosphere to yield carbon aerogels. Monolithic carbon aerogels possessing both microporous and macroporous characteristics were synthesized. It was shown that the microstructure of the carbon aerogels was comprised of spherical particles that could be tailored by control of sol-gel preparation parameters, such as volume ratios of formaldehyde, deionized water and ammonium hydroxide with the resorcinol. The synthesized carbon aerogels had a tapping density as low as 0.11 g/cm 3 and a specific surface area as high as 551 m 2 /g.

show abstract

Photoconductivity of carbon aerogels

Cited by 17 publications

References 15 publications

Direct current electrical conductivity of Versicon™ blended in poly(vinyl chloride)

Direct current electrical conductivity of Versicon™ blended in poly(vinyl chloride)

H2S-Sensing Studies Using Interdigitated Electrode with Spin-Coated Carbon Aerogel-Polyaniline Composites

Rapid Fabrication of Monolithic Carbon Aerogels Based on Resorcinol-Formaldehyde by Ambient Pressure Drying

Contact Info

Product

Resources

About