Hybrid Materials for Low Cost Volatile

Organic Compound Sensor System

Wei-Fang Su*, Geza Toth, Ákos Kukovecz and

Alejandro Alija

2015/09/15

National Taiwan University, Taiwan

Nanordic Oy, Finland

University of Szeged, Hungary

Ingenieros Asesores, Spain

M-ERA.NET PROJECT

Why do we need VOCs sensor?

2

http://china-heatpipe.net/

http://home.focus.cn/

http://www.fengtay.org.tw

Volatile organic compounds (VOC)

Metabolic and pathophysiologic

processes for diagnosing diseases

VOCs used in our daily life

Chemical explosions in Taiwan

3

Toluene leakage in chemical plant

and explosion incident in 2012.

Propene leakage in underground

pipes and explosion incident in 2014.

2015 Chemical Explosion in Tianjin, China

4

Toxic chemical vapors and harmful dusts after the accident: toluene, chloroform, DNBP, ethylene oxide (epoxyethane), trichloroethylene…

Common VOCs

5

Pentane

Hexane

Octane

Decane

Dodecane

Chloroform

Dichloromethane

1,2-Dichloroethane

Tetrachloroethylene

Chlorobenzene

Dichlorobenzene

Trichlorobenzene

Alkanes

Aromatics

Chlorides

Chloro-

aromatics

Benzene

Toluene

Xylenes

Others

Acetaldehyde

Acetone

Diethyl Ether

Tetrahydrofuran

Objectives of this project

6

Low cost, high sensitivity, mobile VOC sensor system to

prevent disastrous, keep clean and healthy environment

Measurement range: 0-20,000ppm

Sensitivity/Detection limits: ppm, below OSHA PELS (8

hour time weight average)

Response time: less than 1 min

New hybrid materials and adding automated data

acquisition system.

The system enables warning through visible and/or

audible alarm, smart cell phone or computer message.

Team communication and teamwork

7

Kick-Off Meeting in Taipei, 2013

First Year Review Meeting

in Szeged, 2014

http://www.vocsensor.com/

Teamwork

8

Advantage of our sensors (NTU)

9

Commercial VOCs sensors usually detects hydrogen sulfide,

carbon oxides, ammonia, alcohols… etc.

Aromatic or chloride based compounds are hard to detect even

with large tolerance.

Our sensors based on optical property difference are suitable

for detection of these hazards.

450 500 550 600 6500.00

0.02

0.04

0.06

0.08

0.10

0.12

Ab

so

rba

nc

e (

N.A

.)

Wavelength (nm)

initial 15 min

1 min 30 min

3 min 60 min

5% toluene

Incident light

Glass Hybrid film

(UV-Vis spectrum)

Before VOCs exposure

Expose to VOC

After VOCs exposure

Sensor chips evolution

10

Before Project

YEAR 1 YEAR 2 YEAR 3

Gen 4

HT71-5F1

HT71-5F3

HT71-5F5

HT71-5F10

HT71-3F1

HT71-3F3

HT71-3F5

HT71-3F10

HT71-1F1

HT71-1F3

HT71-1F5

HT71-1F10

Gen 1 HT61B

HT61F

Gen 2

HT71

OT71

Gen 3

H1O1

H1O3

H3O1

Sen

siti

vit

y

Structure effect on sensors (1)

11

Chemical P3BT:PC71BM P3HT:PC71BM P3OT:PC71BM

Water (ref.) 0.00 0.00 0.01

Methanol 0.01 0.03 0.00

Ethanol 0.03 0.03 0.00

1-Butanol -0.01 0.03±0.01 0.00 1-Propanol 0.01 0.03 0.01

i-Pentane 0.07 0.81±0.02 0.31 n-Hexane 0.15±0.01 0.85±0.05 0.44

n-Octane 0.03 0.78±0.06 0.26 n-Decane 0.01 0.47±0.06 0.28

n-Dodecane 0.03 0.49±0.03 0.27

Summary of P3AT:PC71BM films sensing at saturated vapor pressure of various VOCs for

10 min.*

*The average value of R600/480 from 5 samples.

Structure effect on sensors (2)

12

Chemical P3BT:PC71BM P3HT:PC71BM P3OT:PC71BM

Toluene 0.49 1.25±0.01 0.38 m-Xylene 0.38 1.07 0.46

o-Xylene 0.32 1.07±0.05 0.49

p-Xylene 0.36 1.14±0.02 0.41

Pyridine 0.35 1.08±0.03 0.68

Chlorobenzene 0.46±0.01 1.01±0.04 0.52

Dichlorobenzene 0.22 0.97±0.06 0.40

Trichlorobenzene 0.34 0.98±0.10 0.47

Dichloromethane 0.57±0.01 1.34±0.20 0.36

Chloroform 0.47 1.19±0.03 0.76

1,2-Dichloroethane 0.47 1.06±0.05 0.45

Tetrachloroethylene 0.52 1.12±0.03 0.50

Acetaldehyde 0.23 0.73±0.03 0.27

Acetone 0.11 0.70±0.05 0.24

Diethyl ether 0.39 1.22±0.08 0.52

Tetrahydrofuran 0.39 1.18±0.08 0.65

P3OT has showed faster and sharper response than P3HT mainly due to longer alkyl side chain.

It’s crucial for polymers to have high chain mobility and tendency to crystalline since lower concentration of VOCs provides lower driving force.

Detection Baseline

13

A600/480 of P3AT:PCBM films have

variation in air due to instability of UV-

vis spectrometer, air flow, minor

temperature fluctuation and moving

tendency of polymer chain.

The detection of VOC needs to

overcome the natural signal fluctuation.

0 10 20 30 40 50 60-0.01

0.00

0.01

0.02 P3OT H1O3 H1O1

H3O1 P3HT

A600/4

80 (

a.u

.)

Eclipse time (min)

A600/480 of different sensors in air at 20°C.

Normalized absorbance as sensing response for P3AT:

𝐑𝟔𝟎𝟎/𝟒𝟖𝟎 =𝐀𝟔𝟎𝟎/𝟒𝟖𝟎 𝐚𝐟𝐭𝐞𝐫 𝐞𝐱𝐩𝐨𝐬𝐮𝐫𝐞 − 𝐀𝟔𝟎𝟎/𝟒𝟖𝟎(𝐛𝐞𝐟𝐨𝐫𝐞 𝐞𝐱𝐩𝐨𝐬𝐮𝐫𝐞)

𝐀𝟔𝟎𝟎/𝟒𝟖𝟎(𝐛𝐞𝐟𝐨𝐫𝐞 𝐞𝐱𝐩𝐨𝐬𝐮𝐫𝐞)

Threshold response: R600/480 = 0.02

𝐀𝟔𝟎𝟎/𝟒𝟖𝟎 = 𝐀𝟔𝟎𝟎/𝐀𝟒𝟖𝟎

Gasoline Test

14

Large and fast response to

all 4 kinds of commercial

gasoline

Promising applications in oil

leakage in pipes/ tanks/

factories for warning.

0 20 40 600.0

0.2

0.4

0.6 98 92 95 Diesel

R6

00/4

80 (

a.u

.)

Eclipse Time (min)

Gasoline

type 92 95 98 diesel

Detection

Time (min) 4 6 2 18

BTX Test

15 Total VOC concentration: 10000ppm

A

B

C

D

Benzene

Toluene Xylene

A

B C D

0 10 20 30 40 50 600.0

0.2

0.4

0.6

0.8 A B

C D

R600/4

80 (

a. u

.)

Eclipse Time (min)

VOC adsorption on sensor candidates

(SZTE, Hungary)

16

Thiomethoxam adsorption on CNTs

Chemosphere 141 (2015) 87-93.

Chlorinated phenol adsorption on MWCNTs

RSC Advances 5 (2015) 24920-24929.

Basic research on interface phenomena

17

MWCNT/organic solvent interface

“evaporation profile”

Microporous and Mesoporous Materials 209 (2015) 105-112.

Water adsorption and proton transport

mechanism study on CePO4 nanowires

ACS Applied Materials and Interfaces 7 (2015) 9947-9956.

Electrochemical detection of Pb2+ and Cd2+ using a BiOCl modified

MWCNT system

Talanta 134 (2015) 640-649.

Models of Fluctuation Enhanced Sensing are

developed for several inorganic materials

18

Low temperature conversion of titanate nanotubes into nitrogen-doped

TiO2 nano particles

CrystEngComm 16 (2014) 7486-7492.

Other papers

Carbon Paste Electrodes Bulk-Modified with Carbon Nanotubes and Chemically Oxidized Carbon Nanotubes for the Determination of Hydrogen Peroxide, Sensing in Electroanalysis, Vol. 8 (K. Kalcher, R. Metelka, I. Švancara, K. Vytr ̌as; Eds.), pp. 195−211. 2013/2014 University Press Centre, Pardubice, Czech Republiic, 2014

Three different clay-supported nanoscale zero-valent iron materials for industrial azo dye degradation: A comparative study, J TAIWAN INST CHEM E 2014: 1, 2014

Decoration of titanate nanowires and nanotubes by gold nanoparticles: XPS, HRTEM and XRD characterization, E-J SURF SCI NANOTECH 12: 252-258, 2014

Synthesis and characterization of polyvinyl alcohol based multiwalled carbon nanotu be nanocomposites, PHYSICA E 61: 129-134, 2014

Toxic metal immobilization in contaminated sediment using bentonite- and kaolinite-supported nano zero-valent iron, J NANOPART RES 16: (8) , 2014

Dynamic origin of the surface conduction response in

adsorption-induced electrical processes, Chemical Physics

Letters 607 (2014) 1-4.

Water-Induced Changes in the Charge-Transport Dynamics of Titanate

Nanowires, LANGMUIR 30: (8) 1977-1984, 2014

Project device evolution (Nanodic, Finland)

19

Existing proof of concept

Development of a conventional design

Development of a prined

intelligence design

(image source: vtt.fi)

(estimated month 30)

(month 18)

VOC Cell – Reflection type

20

• Advantage taken on multiple passes through

the sensing layer/other interfaces

VOC Cell – Reflection/advanced type

21

• Tray function for multiple samples

• Fan assisted VOC delivery

VOC Cell – Transmission type

22

• Tray mechanism

• Small form factor

VOC Cell – Transmission type

23

Working prototype

• OLED display

• Menu function

• One button testing

• Programmable

Future generation device development

24 Smart IoT devices, with touch interface

VOCSENSOR IoT device: Design and Prototyping

(IA, Spain)

25

3D computer design 3D printing

VOCSENSOR prototype D&D by IA.

ABS-like plastic material printed by 3D optical lithography Free solidification, also known as SLA.

More info here: https://youtu.be/sHqHWTK-Esg?t=44

VOCSENSOR IoT device: In Lab tests

26

Dilutor 1

Dilutor 2

Bubbler

Vocsensor

device

Nitrogen

bottle

PC

N2

N2

N2 N2

N2

N2Y + CH2CL2

VOCSENSOR IoT device: Results sample

27

1000

1200

1400

1600

1800

2000

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55

Tra

nsm

ite

d i

nte

nsi

ty

(co

un

ts)

Resistance (a.u)

Dicloromethane 50% saturation N2 balance

590 nm 10 min470 nm 10 min590 nm 30 min470 nm 30 min590 nm ambient470 nm ambient590 nm 1 min

Intensity amber

Blue wavelenght

Amber

wavelenght

VOCSENSOR IoT device: Application Mockup

28

Conclusions

29

Several new sensing

materials are

developed and have

improved sensitivity

more than 10 times.

Low price sensor

prototype is realized

through device

design and 3-D

printing.

BTXs testing,

humidity tests and

on-field tests all show

positive results.

Models of Fluctuation

Enhanced Sensing

are developed.

Sensor box Warning light

Circuit

Plexiglas box

VOCs sensor publication

30

Romantic Story or Raman Scattering Rose Petals as Ecofriendly, Low-Cost Substrates for Ultrasensitive Surface-Enhanced

Raman Scattering,” 2015, Analytical Chemistry, 87, 6017-6024

“Trifluoroacetylazobenzene for optical and electrochemical detection of amines,” 2015, Journal of Materials Chemistry A, 3,

4687-4694

“Hybrid Poly(3-hexyl thiophene):TiO2 Nanorods Oxygen Sensor,” 2014, RSC Advances, 4 (44), 22926-22930.

“Photocatalytic Activity of Nitrogen doped TiO2-based Nanowires：A Photo-Assisted Kelvin Probe Force Microscopy Study,”

2014, Journal of Nanoparticle Research, 16:2143-2154.

“Surface-enhanced Raman Scattering Substrate Based on Ag Coated Monolayer Sphere Array of SiO2 for Organic Dye

Detecting,” 2013, RSC Advances 4, 10043-10050.

“Conjugated Polymer/ Nanoparticles Nanocomposites for High Efficient and Real-Time Volatile Organic Compounds

Sensors,” 2013, Analytical Chemistry 85, 9305-9311.

“Decoration of Titanate Nanowires and Nanotubes by Gold Nanoparticles: XPS, HRTEM and XRD Characterization,” 2014,

e-Journal of Surface Science and Nanotechnology, 12, 252-258.

“Dynamic origin of the surface conduction response in adsorption-induced electrical processes,” 2014, Chemical Physics

Letters, 607, 1-4.

“Water-induced changes in the charge-transport dynamics of titanate nanowires,” 2014 Langmuir 30 1977-1984.

“Carbon Paste Electrodes Bulk-Modified with Carbon Nanotubes and Chemically Oxidized Carbon Nanotubes for the

Determination of Hydrogen Peroxide,” 2013/2014 Sensing in Electroanalysis 8 195-211.

“Synthesis and characterization of polyvinyl alcohol based multiwalled carbon nanotube nano composites,” 2014 Physica E

61 129-134.

“Low temperature conversion of titanate nanotubes into nitrogen-doped TiO2 nano particles,” 2014 CrystEngComm 16

7486-7492.

“Toxic metal immobilization in contaminated sediment using bentonite- and kaolinite-supported nano zero-valent iron,” 2014

Journal of Nanoparticle Research.

“Three different clay-supported nanoscale zero-valent iron materials for industrial azo dye degradation: A comparative

study,” 2014 Journal of the Taiwan Institute of Chemical Engineers.

31

32

Field test movie

https://www.youtube.com/

watch?v=Mjo4sLiByA0&feat

ure=player_embedded

Project website

http://www.vocsensor.com/

Thank you for your attention!