Giant Temperature Coefficient of Resistance in Carbon Nanotube/Phase‐Change Polymer Nanocomposites

The temperature coeffi cient of resistance of a carbon nanotube nanocom- posite with the non-conductive phase-change hydrogel Poly(N-isopropy- lacrylamide) is studied. This nanocomposite is found to achieve the largest reported temperature coeffi cient of resistance, ≈ − 10%/ ° C, observed in carbon nanotube-polymer nanocomposites to date. The giant temperature coeffi - cients of resistance results from a volume-phase-transition that is induced by the humidity present in the surrounding atmosphere and that enhances the temperature dependence of the resistivity via direct changes in the tunneling resistance that electrons experience in moving between nearby carbon nano- tubes. The bolometric photoresponses of this new material are also studied. The nanocomposite's enhanced responses to temperature and humidity give it great potential for sensor applications and uncooled infrared detection.

[1]  Daihua Zhang,et al.  Transparent, conductive, and flexible carbon nanotube films and their application in organic light-emitting diodes. , 2006 .

[2]  Christian Vieider,et al.  MEMS-based uncooled infrared bolometer arrays: a review , 2007, SPIE/COS Photonics Asia.

[3]  P. Sheng,et al.  Hopping Conductivity in Granular Metals , 1973 .

[4]  M. Heskins,et al.  Solution Properties of Poly(N-isopropylacrylamide) , 1968 .

[5]  Robert C. Haddon,et al.  Bolometric Infrared Photoresponse of Suspended Single-Walled Carbon Nanotube Films , 2006, Science.

[6]  John R. Reynolds,et al.  Transparent, Conductive Carbon Nanotube Films , 2004, Science.

[7]  Niraj Sinha,et al.  Carbon nanotube-based sensors. , 2006, Journal of nanoscience and nanotechnology.

[8]  Dipankar Chakravorty,et al.  Electrical resistivity of copper-silica nanocomposites synthesized by electrodeposition , 1998 .

[9]  Eric S. Snow,et al.  Random networks of carbon nanotubes as an electronic material , 2003 .

[10]  N. Turro,et al.  Consolvency of poly(N-isopropylacrylamide) in mixed water-methanol solutions: a look at spin-labeled polymers , 1992 .

[11]  Nevill Mott,et al.  Conduction in non-crystalline materials , 1989 .

[12]  Markus Brink,et al.  Tuning carbon nanotube band gaps with strain. , 2003, Physical review letters.

[13]  Zettl,et al.  Extreme oxygen sensitivity of electronic properties of carbon nanotubes , 2000, Science.

[14]  E. Campbell,et al.  Carbon nanotube bolometers , 2007 .

[15]  D. McLachlan.  A quantitative analysis of the volume fraction dependence of the resistivity of cermets using a general effective media equation , 1990 .

[16]  A. Fernández-Nieves,et al.  Swelling kinetics of poly(N-isopropylacrylamide) minigels. , 2006, The journal of physical chemistry. B.

[17]  T. Masuda,et al.  Swelling and deswelling kinetics of poly(N-isopropylacrylamide) gels. , 2004, The Journal of chemical physics.

[18]  Boris I Shklovskii,et al.  Coulomb gap and low temperature conductivity of disordered systems , 1975 .

[19]  Judy Z. Wu,et al.  Suspending single-wall carbon nanotube thin film infrared bolometers on microchannels , 2009 .

[20]  M. White,et al.  Temperature Dependence of Thermal Conductivity Enhancement in Single-walled Carbon Nanotube/polystyrene Composites , 2010 .

[21]  H. G. Schild.  Poly(N-isopropylacrylamide): experiment, theory and application , 1992 .

[22]  Huisheng Peng,et al.  Aligned carbon nanotube/polymer composite films with robust flexibility, high transparency, and excellent conductivity. , 2008, Journal of the American Chemical Society.

[23]  Mei Zhang,et al.  Sign Change of Poisson's Ratio for Carbon Nanotube Sheets , 2008, Science.

[24]  Paul W. Kruse,et al.  Uncooled Thermal Imaging Arrays, Systems, and Applications , 2001 .

[25]  W. Euler,et al.  Achieving High Mid‐IR Bolometric Responsivity for Anisotropic Composite Materials from Carbon Nanotubes and Polymers , 2012 .

[26]  Hongjie Dai,et al.  Carbon nanotubes: synthesis, integration, and properties. , 2002, Accounts of chemical research.

[27]  X. Sun,et al.  Infrared sensors based on multi-wall carbon nanotube films , 2010 .

[28]  K. Iwai,et al.  Fluorescence label studies of thermo-responsive poly(N-isopropylacrylamide) hydrogels , 2000 .

[29]  R. Jones,et al.  The General Theory of Bolometer Performance , 1953 .

[30]  A. Aliev.  Bolometric detector on the basis of single-wall carbon nanotube/polymer composite , 2008 .

[31]  P. Richards.  Bolometers for infrared and millimeter waves , 1994 .