Propositions 1. Sulfonation of polyaniline enables detection of CO 2 due to shifting of the pH-induced conductivity to the carbonic acid pH regime. (This thesis) 2. ‘Direct’ CO 2 sensing via a reaction between CO 2 and amine groups of polyethyleneimine and its blends yields better sensitivity than ‘indirect’ CO 2 sensing via carbonic acid formation. (This thesis) 3. Dip-pen nanolithography using electrostatic interactions as a driving force, proposed by Mirkin and co-worker, is the best way to obtain patterned nanowires of water-soluble conductive polymers. (J.H. Lim, C.A. Mirkin, Advanced Materials, 14 (2002) 1474-1477) 4. Just heating poly(anthranilic acid) is not sufficient for complete removal of its ionized carboxyl groups (–COO - ), as claimed by Ogura et al. (K. Ogura et al., Journal of Electroanalytical Chemistry, 522 (2002) 173-178, K. Ogura, H. Shiigi, Electrochemical and Solid-State Letters, 2 (1999) 478-480, K. Ogura et al., Journal Polymer Science, Part A: Polymer Chemistry, 37 (1999) 4458-4465). 5. Polymer thin films for highly selective, sensitive and reversible CO 2 sensors still have a long journey to practical applications. 6. Interdisciplinary research is a good thing, transdisciplinary research is better. 7. Doing measurements with high CO 2 concentrations on weekends has a higher risk of creating doziness than motorbike riding in Ho Chi Minh City during rush hours. 8. The large number of motorbikes in Ho Chi Minh promotes plant growth within the city. Propositions belonging to the thesis, entitled “Conductive Polymers for Carbon Dioxide Sensing” Tin Chanh Duc Doan Wageningen, 29 October 2012 Conductive Polymers for Carbon Dioxide Sensing Tin C. D. Doan Thesis committee Thesis supervisor Prof. dr. C.J.M. van Rijn Professor of Microsystem and Nanotechnology for Agro, Food and Health Wageningen University Other members Prof. dr. E.J.R. Sudhölter Delft University of Technology Prof. dr. ir. F.A.M. Leermakers Wageningen University Prof. dr. ing. E.J. Woltering Wageningen University Prof. dr. S.G. Lemay University of Twente, Enschede This research was conducted under the auspices of the Graduate school VLAG (Advanced studies in Food Technology, Agrobiotechnology, Nutrition and Health Sciences). Conductive Polymers for Carbon Dioxide Sensing Tin C. D. Doan Thesis submitted in fulfillment of the requirements for the degree of doctor at Wageningen University by the authority of the Rector Magnificus Prof. dr. M.J. Kropff, in the presence of the Thesis Committee appointed by the Academic Board to be defended in public on Monday 29 October 2012 at 4 p.m. in the Aula. Tin C. D. Doan Conductive Polymers for Carbon Dioxide Sensing Thesis, Wageningen University, Wageningen, The Netherlands (2012) With references, with summaries in English, Dutch and Vietnamese ISBN: 978-94-6173-410-5 “I can accept failure but I can’t accept not trying” – Michael Jordan Dedicated to my older sister, my family and Little Turtle Table of Contents Chapter 1 General Introduction 1 Chapter 2 Carbon Dioxide Sensing with Sulfonated Polyaniline 27 Chapter 3 Decoupling Intrinsic and Ionic Conduction in Sulfonated Polyaniline in the Presence of Water Vapor as Analyte 47 Chapter 4 Carbon Dioxide Detection at Room Temperature with Polyethyleneimine-based Chemiresistor 77 Chapter 5 Improved Carbon Dioxide Sensing of Polyethyleneimine Blended with Other Polyelectrolytes 99 Chapter 6 General Discussion 123 Appendix 1 Supplementary Information for Chapter 2 143 Appendix 2 Supplementary Information for Chapter 3 149 Appendix 3 Supplementary Information for Chapter 4 165 Appendix 4 Supplementary Information for Chapter 5 167 Summary 173 Samenvatting 177 Tóm Tắt 181 Curriculum Vitae 185 List of Publications 187 Overview of Completed Training Activities 189 Acknowledgement 191 [...]... Hydrogen, Carbon Dioxide, and Hydrocarbon Gas Sensor Technology Using GaN and ZnO-Based Devices, Sensors, 9 (2009) 4669-4694 [31] A Star, T.R Han, V Joshi, J.C.P Gabriel, G Grüner, Nanoelectronic Carbon Dioxide Sensors, Adv Mater., 16 (2004) 2049-2052 [32] S Sivaramakrishnan, R Rajamani, C.S Smith, K.A McGee, K.R Mann, N Yamashita, Carbon nanotube-coated surface acoustic wave sensor for carbon dioxide sensing, ... CO2 would not protonate EB-PANI film Therefore, the doping mechanism of EB-PANI with carbonic acid which was proposed by Ogura et al still needs clarification 1.4 Self-Doped Sulfonated PANI with Extended pH Response for CO2 Sensing 1.4.1 Self-Doping in Conductive Polymers As mentioned above, for oxidation doping or protonation doping (p-doping) of conductive polymers, it requires intrusion of charged... review, three popular conductive polymers including PANI, PPy and poly (3,4-ethylenedioxythiophene) used as active layers in various types of gas sensors have been reviewed Two popular conductive polymers including PPy and PANI have been reported to be used for CO2 detection Measured sensing parameters, configurations of the sensors, sensing mechanism and the factors that affect the performances of these... to form carbonic acid In principle, carbonic acid with pH4-pH6 can be detected by a pH sensor with a conductive polymer as a sensing material The mechanism of CO2 sensing based on protonation of EB-PANI with carbonic acid was firstly proposed by Ogura and his co-workers [5, 56, 57, 60] when they showed a working CO2 sensors based on a composite film of EB-PANI and PVA The acidic doping of EBPANI by carbonic... reference for both 100% CO2 and ambient CO2 levels (~420 ppm) However, the sensor exhibited poor selectivity to CO2 and the measurement was done only in dry condition because water vapor created large interference 1.3 Conductive Polymers for CO2 Sensing 1.3.1 Conductive Polymers A polymer that possesses the electrical, magnetic and/or optical properties of a metal is termed a “synthetic metal” [34, 35] Conductive. .. anions result in tuning the properties of the conductive polymers, leading to a wide range of properties and applications However, in some doping processes such as photo-doping and charge injection there is no counter dopant ion involved [35] 7 Chapter 1 1.3.2 Literature Review on Conductive Polymers for CO2 Sensing In recent years, many sensors using conductive polymers to detect different kinds of gases... were explored for CO2 sensing at low concentrations (below 3,000 ppm) in Chapter 5 Finally, the major achievements of this research are summarized and discussed in Chapter 6 In addition, discussions on different aspects of CO2 sensing based on conductive polymers and organic polymers are presented Furthermore, some perspectives and further researches are suggested to develop CO2 sensors for use in greenhouses... of a metal is termed a “synthetic metal” [34, 35] Conductive polymers often have alternating single and double bonds along the polymer chain, which enable the delocalization or mobility of charge carriers along the polymer backbone; therefore, conductive polymers are also called “conjugated polymers [36, 37] Among many developed conductive polymers, the conjugated systems based on aromatic rings such... weak chemical interaction for fast reversibility Moreover, in greenhouses the humidity is maintained at a high level between 70-90% RH Exposure to high humidity and different analytes in greenhouse environment for a long time normally leads to rapid deterioration of the polymers Therefore, the motivation of this research is to develop a CO2 gas sensor modules based on conductive polymers/ composites with... greenhouse work under high humidity 75-90% RH Water vapor is needed for CO2 indirect sensing to create carbonic acid to protonate the conductive polymers Hence, humidity is also a main analyte which can interfere with the CO2 response Water vapor may induce similar response as CO2 or improve the CO2 response, conductivity strongly depends on RH Therefore, the effect of humidity on intrinsic conductivity of PANI, . thesis, entitled Conductive Polymers for Carbon Dioxide Sensing Tin Chanh Duc Doan Wageningen, 29 October 2012 Conductive Polymers for Carbon Dioxide Sensing . Supplementary Information for Chapter 2 143 Appendix 2 Supplementary Information for Chapter 3 149 Appendix 3 Supplementary Information for Chapter 4 165 Appendix 4 Supplementary Information for. Health Sciences). Conductive Polymers for Carbon Dioxide Sensing Tin C. D. Doan Thesis submitted in fulfillment of the requirements for the degree of doctor