fax:040-23156128 e-mail: kmukkanti@yahoo.com.

ph: off: 040-23155413 res:040-23156955 cell:9346325591

dr.k.mukkanti ph.d professor & head________________________________________________________________________ to 24thaug2007 the registrar jnt university kukatpally, hyderabad 500 072. sir, (through proper channel) sub: request to permit for submission of the r & d project entitled detection of ammonia in the environment by using swcnt/s-pani composite thin film sensor to ugc and issue the forwarding certificate - reg i am submitting a r & d project proposal detection of ammonia in the environment by using swcnt/s-pani composite thin film sensor . this project work if sanctioned will be carried out at jntu, hyd. i request you to permit for the same and issue a forwarding certificate for submission to ugc, new delhi. thanking you, yours faithfully,

(k.mukkanti)

1

date: 23rd aug 2007 to, the secretary university grants commission new delhi sir, a research project entitled detection of ammonia in the environment by using swcnt/s-pani composite thin film sensor 1. it is certified that same project or the investigator has not submitted project with similar objectives to any other funding agency. 2. we have carefully read the terms and conditions of sanctioning the project and agree to abide by them. 3. the organization will provide all necessary infrastructure facilities (both laboratory and administrative) if the project is sanctioned. 4. the organization is fully responsible in regard to matters pertaining to the project. 5. certified that the equipments proposed in the project are not available in our institution.

yours faithfully, place : hyderabad date : (registrar)

fax:040-23156128 e-mail: kmukkanti@yahoo.com.

ph: off: 040-23155413 res:040-23156955 cell:9346325591

dr.k.mukkanti ph.d professor & head________________________________________________________________________certificate by the principal investigator/co-investigator

1. certified that at present we are not receiving any funds from the ministry for any other project.

2. certified that the equipments proposed in the present project proposal are not available in my laboratory/ institution

dr.k.mukkanti place : hyderabad

date :(principal-investigator)

3

appendix 1

proforma of application for research grants (please read carefully the guidelines to investigators before filling this proforma) 1 research station / institution centre for environment centre for environment, institute of science & technology, jnt university, kukatpally, hyderabad- 500085 telephone fax e-mail nearest rail head/airport 2 principal investigator dr.k.mukkanti professor & head centre for environment, institute of science & technology, jnt university, kukatpally, hyderabad-500085 telephone fax e-mail 040-23155413 04023155413 kmukkanti@yahoo.com 040-23155413 040-23155413 kmukkanti@yahoo.com hyderabad

name address

name designation address

3.

brief bio-data of the investigators

(enclosed at the end of the proposal) 4. project title (keep it as short as possible) -

detection of ammonia in the environment by

using swcnt/s-pani composite thin film sensor 5 track record and workload assessment of the pi

list all the research and consultancy schemes, whether funded by mowr or any other agency, in which the present pi is/was principal investigator, in following groups. a. schemes completed -1 (m b. schemes foreclosed with reasons for foreclosure c. schemes ongoing -2 6 if the scheme is sanctioned, in whose name the cheque is to be issued. (write precise title of the account) director, ist, jnt university 7 category of r&d activity (tick those which are applicable) a. basic research b. applied research c. action research d. education & training e. mass awareness programme f. infrastructure development g. creation of centres of excellence

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description of the proposal

polyaniline (pani) was another extensively studied conducting polymer which has high stability, good conductivity and reversible redox property. sulfonated polyaniline (spani) has sulfonic groups on its backbones, so it is soluble in water. spani with methoxyls on its benzene rings has been used as the dopant for ppy and the resulting composite film exhibited improved cathodic expansions. herein, we report the syntheses and characterizations of ppy/spani self-standing films by direct oxidation of pyrrole in the aqueous solution of spani. these films showed unique electrochemical properties and high performance on ammonia gas sensing. a novel conductive polyaniline is synthesized using poly (4-styrenesulfonateco-maleic acid) as counter ion and template. the resistance of this electro active polymer increases in the presence of gases such as ammonia. this transducing property is exploited and spin-cast film of this material on glass substrate is established as ammonia gas sensor module, for gas concentrations in the range 5250 ppm. in this range, the response and recovery times are typically 501000 s. the resistance response (r/r0) at short time scales of about 150 s, is shown to vary linearly with the ammonia concentration. qualitative and quantitative analysis of chemical and biochemical substances present in the environment have tremendous importance in connection with environmental monitoring, personal protection, safety and process control. development and fabrication of systems for this purpose are of great contemporary interest. choice of suitable sensing materials along with efficient microelectronics for the detection system is the key step in such efforts. a wide range of materials of organic and inorganic origin are used as sensing elements. inorganic materials such as the oxides of tin and zinc have been used extensively. one of the practical problems with oxide sensors is the need to adopt high operating temperatures. organic compounds as sensor active materials circumvent this limitation since they operate at ambient temperatures. several types of organic materials have been used for gas sensing. these include porphyrins, phthalocyanines and conjugated polymers. conducting conjugated polymers offer major advantages because of the facility with which the recognition elements can be tailored by chemical synthesis and thin film fabrication techniques. an ammonia sensor based on conducting polypyrrole was one of the early practical realizations of conducting polymer sensors. its sensitivity, however, was relatively low and the response not very reversible. we have recently investigated the control of spani formation using polyelectrolyte templates. in recent years, a lot of attention has been given to the use of conducting

polymers in chemical sensors, as sensing layers for gases detection, because of merits such that easy fabrication, low power consumption, and low poisoning effect. sno2 and fe2o3. the principal advantages of such materials include high dependence on the detecting environments. however, the presented optical method shows independence from environmental interference. the polyaniline films show significant optical transmittance changes upon exposure to ammonia gas at room temperature. this study demonstrates the optical property advantage of polyaniline (pani) over metal oxide. 9 objectives. classify the objectives of proposed research under one or more of following and explain the objectives briefly.

polyaniline (pani) was found to be a better choice for gases such as ammonia because of its higher sensitivity, reversible response and shorter response time. the effect of ammonia and water on the conductivity of polyaniline has been investigated along with the polymer adsorption capacity. the

transducing behavior of polyaniline has been exploited in thin film sensors for several gas molecules as well as volatile organic compounds. in spite of the various advantages of conducting polymer based gas sensors, some fundamental problems persist. the fabrication of good quality films is often hampered by solubility problems. long-term mechanical and chemical stability of the polymeric materials are points of concern in many instances. sensitivity of the responses is not always satisfactory. in such a case ammonia sensors based on swcnts/sulphonated pani (s-pani) there will a considerable improvement of reversibility and reproducibility of the

processes involved in the sensing action.

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10

putting the research to use

a. identify the possible end-users for the results of proposed research. b. list the actions that will be necessary to put the results to use. c. list the difficulties/problems that may be encountered in putting the results to use. d. are the possible end users being involved in the research ? if yes then describe how, if not then explain why not. 11 present state of art conducting polymers constitute a new class of sensing materials, that are prepared by a simple oxidative polymerization method. since their discovery, intrinsic conducting polymers (icps) have been investigated intensively because of a select group of properties that they exhibit: electronic conduction, environmental stability on the conducting state, reversible redox reactions, electrocromism, and electroluminescence. conducting polymers offer themselves as an excellent sensing materials, among the many, polypyrrole (ppy) is the most extensively used in the designing materials for chemical gas sensors. versatility of this polymer is determined by a number of potential applications: strong absorptive properties towards gases, dna proteins, catalytic activity and, corrosion protection properties etc. ppy and ppy doped with copper films revealed increasing the resistance by exposure of reducing gases such nh3, h2 and co.

references: 1. b. li, g. sauv, m. c. iovu, m. j.-el, r. zhang, j. cooper, s. santhanam, l. schultz, j. c. revelli, a. g. kusne, t. kowalewski, j. l. snyder, l. e. weiss, g. k. fedder, r. d. mccullough, and d. n. lambeth, volatile organic compound detection using nanostructured copolymers, nano lett., 6 (2006) pp.1598 -1602. 2. wiley periodicals, inc. j appl polym sci 92: 3742, 2004 3. k. potje-kamloth, chemical gas sensors based on organic semiconductor polypyrrole, critical rev. anal. chem. 32 (2002) pp. 124-140. 4. m.m. chehimi, m.l. abel, c. perruchot, m. delamar, s.f. lascelles and s.p. armes, synth. met. 104 (1999) pp. 51-59 5. b. saoudi, c. despas, m.m. chehimi, n. jammul, m. delamar, j. bessiere and a. walcarius, sens. actuators b 62 (2000) pp. 35-42 6. azioune, f. siroti, j. tanguy, m. jouini, m.m. chehimi, b. miksa and s. slomkowski, electrochim. acta 50 (2005) pp. 16611667http://www.sciencedirect.com/science?_ob=articleurl&_udi=b6tg0-4dvbdy82&_user=2354535&_coverdate=02%2f15%2f2005&_fmt=summary&_orig=search&_cdi=5 240&view=c&_acct=c000057047&_version=1&_urlversion=0&_userid=2354535&md5=3 3d995df5ca8474fbaf52abaae 7. v.g. khomenko, v.z. barsukov and a.s. katashinskii, electrochim. acta 50 (2005) pp. 1675-1688 8. n.t.l. hien, b. garcia, a. pailleret and c. deslouis, electrochim. acta 50 (2005) pp. 1747. 9. l. torsi, m. pezzuto, p. siciliano, r. rella, sabbatini, l. valli, p. g. zambonin, conducting polymers doped with metallic inclusions: new materials for gas sensors, sens. acuators, b, chem. 48 (1998) 362-367 10.matsuguchi, m.; io, j.; sugiyama, g.; sakai, y. synth met 2002, 128, 15 11.chabukswar, v. v.; pethkar, s.; athawale, a. a. sens actuators b 2001, 77, 657. 12.jin, z.; su, y.; duan, y. sens actuators b 2001, 72, 75. 13.li, d.; jiang, y.; wu, z.; chen, x.; li, y. sens actuators b 2000, 66, 125. 14.agbor, n. e.; petty, m. c.; monkman, a. p. sens actuators b, 1995, 28, 173. 15.nicho, m. e.; trejo, m.; garcia-valenzuela, a. sens actuators b, 2001, 75, 18. 16.oh, k. w.; hong, k. h.; kim, s. h. j appl polym sci 1999, 74, 2094. 17.lee, d. s.; rue, g. r.; huh, j. s.; choi, s. d.; lee, d. d. sensactuators b 2001, 77, 95. 18.muellerleile, j. t.; freeman, j. j. j appl polym sci 1994, 54, 135. 19.macdiarmid, a. g.; chiang, j. c.; richter, a. f.;epstein, a. j.synth met 1987, 18, 317. 20.hu, h.; trejo, m.; nicho, m. e.; saniger, j. m.; garcia-valenzuela, sens actuators b 2002, 82, 14. 9

21.gasser, r. p. h. an introduction to chemisorption and catalysis by metal; oxford science publications: oxford, uk, 1985; pp.176.22.paterno, l. g.; manolache, s.; denes, f. synth met 2002, 130, 85.

12 1.

methodology among organic conducting polymers, polyaniline (pani) is regarded as

one of the most technologically promising conductive polymers because the monomer is inexpensive, the polymer can be easily prepared by oxidative polymerization with high yield, and products are stable under ambient conditions.6 promising results have also been shown for application in gas sensors. this mechanism is attributed to the _-conjugated system in the conducting polymer chain. the interaction between the organic material and gas molecules results in an increase/decrease of polaron and/or bipolaron densities inside the band gap of the polymer. therefore their modification implies both electrical and optical property changes in the conducting polymer.

polyaniline (pani) was found to be a better choice for gases such as ammonia because of its higher sensitivity, reversible response and shorter response time. the effect of ammonia and water on the conductivity of polyaniline has been investigated along with the polymer adsorption capacity. the

transducing behavior of polyaniline has been exploited in thin film sensors for several gas molecules as well as volatile organic compounds. in spite of

the various advantages of conducting polymer based gas sensors, some fundamental problems persist. the fabrication of good quality films is often hampered by solubility problems. long-term mechanical and chemical stability of the polymeric materials are points of concern in many instances. sensitivity of the responses is not always satisfactory. in such a case ammonia sensors based on swcnts/sulphonated pani (s-pani) there will a considerable improvement of reversibility and reproducibility of the

processes involved in the sensing action. these films were then deposited by means of dip coating over two comb-like inter-digitated gold electrodes screen-printed on an alumina chip substrate. the change in resistance of spani on exposure to aqueous ammonia has been utilized for the study of a prototype chemical sensor. these properties make possible their use in several practical applications, including batteries, antistatic coatings, electromagnetic interference shields, display, and

capacitors for example. a. preparation of spani pani (in emeraldine form) was synthesized by chemical oxidation of aniline with ammonium persulfate at 00c . pani was sulfonated with chlorosulfonic acid and finally hydrolyzed into spani. swcnts ( single walled carbon nanotube)

additional of swcnts are mainly to enhance the signal to measure lower levels of ammonia. the swcnts were synthesized in the lab or obtained laboratory.

11

b. uv photo polymerization appropriate weight of monomer aniline was added to 100 ml of ethyl alcohol to form solution. approximately quantity of agno3 was added to the solution and stirred thoroughly making it equally distributed in the pyrrole alcohol matrix and available for

polymerization. subsequently, chips will be dip coated with the monomer material. the chip was made of an alumina substrate with dimensions of 10mm 5mm on which pair of comb-like interdigitated gold electrodes were screen printed (see fig.), and followed by uv treated to photo polymerize at room temperature for few hours. polymerisation will be confirmed by uv spectroscopy. c. swcnt/spani thin film preparation swcnt/spani composite films were prepared by mixing required weight percentages of swcnts with spani, and then the mixture is taken into teos solution along with ethanol and water in the ratio 5:16:2. subsequently the chips were dip coated with the mixture solution. d. sensing chip

an alumina chip with dimensions of 10 mm by 5 mm comprising of a pair of comb-like inter-digitated gold electrodes previously screen printed over the substrate was used to dip coat ppy thin films as shown in the figure. sensing material is over the gold electrodes.

these ends of the gold electrodes were connected to the wiring through platinum electrodes.

e. characterization i.uv/vis spectroscopy for confirmation of completion of

polymerization ii.infrared spectroscopy that provides the fingerprint of a molecule. the fingerprint consists of a unique series of energy absorbance across a wavelength range of 2.5 to about 14 micrometers (m). ftir was also used to note the spectral signature of the ammonia in this study.2. fabrication of the test sensor the ammonia sensing performance lm will be studied by measuring electric resistance changes of the swcnt/spani composite thin film in the gas flow of ammonia/nitrogen. these two comb like electrodes were connected to a

potentiostat under computer control. the current signal was recorded by applying a

13

constant voltage between these two electrodes. the concentration of ammonia was controlled by a mass flow controller . the total flow was 1000 sccm (standard cubic centimeter per minute), and the ammonia concentration was modulated to be 20, 40, 60 or 80 ppm by mixing 1000 ppm source ammonia gas with nitrogen flow under mfc control. the mixed gas was led to a glass chamber with a volume of 500 ml in which the sensing device was fixed ammonia gas was 1 min on and then cut off to leave the device under nitrogen flow until the current of the device recovered to its original value. the response was defined by the slope of the current time curve recorded during the period.

3. nh3 gas sensing

the developed sensor to monitor the ammonia sensing by the polymer thin film at room temperature; a schematic view is shown. a 2 l round bottom flask fitted with a stopper was used for this experiment. electrical connections for the sensing element and air-circulating fan were introduced through the stopper and passage was provided for evacuating and introducing the ammonia gas. headspace of a bottle ammoniaair mixture was taken from the ammonia solution. the ammonia

containing

concentration in the mixture was estimated by trapping a known volume in ice-cold dilute hydrochloric acid solution that was titrated with standardized sodium hydroxide before and after the ammonia trapping. uniform

distribution of gas inside the round bottom flask was achieved using the fan. sensor element was fabricated by fixing four electrical probes on the

swcnt/s-pani film using silver paint or sublimed aluminum. a constant current source and multimeter were used to apply current and measure the voltage drop respectively. prior to the introduction of ammonia gas into the round bottom flask it was evacuated and nitrogen gas was introduced to create oxygen-free environment. the resistance of the film in this state is denoted as r0. a known volume of ammonia gas (concentration calibrated as discussed above) was introduced. the fan was operated to distribute the gas uniformly. the resistance was monitored every 10 s till saturation was attained. then the sensor element was removed from the flask and kept in ammonia-free atmosphere to monitor the conductivity recovery. the

ammonia exposure and cut-off cycles were repeated several times to check the reversibility and reproducibility of the sensor element.4. conclusion

the use of modified conducting polymer (spani) composites as sensing elements in chemical sensors is an intensive area of research because of their high sensitivity on electrical or optical changes when exposed to diverse types of gases or liquids. this characteristic holds promise for successful designs of different types of sensor transducers based on conducting polymers. several reports revealed that

conducting polymers as chemical sensors for air-borne volatile organic compounds (especially m ,alcohols, ethers, halocarbons, ammonia, no2, and co2) have a lower detectable limit in the range of a few tens of parts per millions, and the potential to operate at or near room temperature.

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13.

cost estimates

item fellowship jrf (chemistry) travel (within india) consumables a. chemicals b. glassware c. commercial gold chips equipment atomic force microscopy computer

1st 2nd year year 1,15,2 1,15,200 00 20,00 0 60,00 0 25,00 0 25,00 0 20,000

3rd year 1,44,0 00 20,000

total (rs.) 3,74,400

60,000

50,000 25,000 25,000

50,000 25,000 25,000

3,10,000

3,50,000 50,000

4,00,000

50,000 sputtering machine quartz crystal microbalance mass flow controllers -2 50,000 2,50,000 50,000 3,00,000

total

14,94,400

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work schedule a. probable date of commencement immediate after sanction b. duration of study -3 years c. stages of work and milestones

identifiable milestones of months from amount to be released progress start start 0 (amount of first instalment) 1 literature survey 0-6 50% of the amount to be sanction at the begining

2 procuring instruments 3. preparation of polymer thin films 4. study of proprties 5. manufacturing of sensing chip & characterization 6. fabrication of test sensor 7. nh3 gas sensing and application 8. report preparation from remaining 25% to be sanctioned at the end os the first year

remaining amount to be sanctioned at the end of

the 2nd year.

notes: a. the work should be divided into milestones 3 to 6 months apart. b. the milestones are mainly for the purpose of monitoring of progress and release of funds. the funds to be released on achieving various milestones should be indicated. c. normally there may be only one release of funds in a financial year.

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declaration 1. i have carefully read the terms and conditions of the research grant and agree to abide by them. 2. this is to certify that i have neither submitted this proposal elsewhere for financial support nor have undertaken it at the request of any commercial agency or as a consultancy.

date place

signature of pi name designation

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endorsement from the head of the institution 1. the institute / organization welcome the participation of dr.k.mukkanti, professor & head as principal investigator for above project. 2. the necessary equipment and institutional support as described in item 13.3 will be made available as and when required for the purpose of the project to ensure that the work is taken up on priority and completed on schedule. 3. in the event of foreclosure /discontinuation /cancellation of the scheme for any reason , the entire amount released for the scheme will be fully refunded to the mowr along with the interest prescribed till the date of return by the institute/ organisation. 4. the register of permanent and semi-permanent assets acquired out of grants from mowr will be maintained in form gfr-19. 5. the assets acquired out of this grant shall be transferred to the desired destination in good & working condition as and when required.

date : and signature of the place: of the organisation

seal head