THIẾT kế máy bản CHÍNH

HCM UNIVERSITY OF TECHNICAL EDUCATION
FACULTY OF CHEMICAL AND FOOD TECHNOLOGY
CHEMICAL ENGINEERING TECHNOLOGY

SUBJECT : Fundamentals of Design Chemical Machines and Factories

SUBJECTION 13: CARBON NANOMATERIALS-BASED GAS SENSOR

Introductor: TS. Lý Tấn Nhiệm

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MEMBERS OF TEAM 8

Trần Thanh Huy -19128002

Huỳnh Thị Yến Ly-19128048

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MEMBERS OF TEAM 8

Nguyễn Bình Đẵng- 19128027

Nguyễn Văn Tân- 19128069

Nguyễn Thanh Vinh- 19128101
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CONTENTS OF PRESENTATION

01

03
APPLIC

W

Application of gas sensors in

Summary about the gas sensor

life

in nanocarbone

INTRODUCTION

Concept of the gas base
sensor

CONS
04

02
REVIE
Outstanding research methods

ATION

LUSIO
N

4


1. INTRODUCTION

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1.INTRODUCTION
Basic criteria for good and efficient gas sensing systems:
(i) high sensitivity and selectivity; 

(ii) fast response time and recovery time;

(iii)low analyst consumption;

(iv) low operating temperature and temperature independence;

(v) stability in performances.
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1.INTRODUCTION
- The recent development of nanotechnology has created a huge potential to build highly sensitive, low-cost, portable sensors with low power
consumption. The extremely high surface-to-volume ratio and hollow structure of nanomaterials are ideal for gas molecules adsorption and storage.

 Therefore, gas sensors based on nanomaterials, such as carbon nanotubes (CNTs) have been investigated widely.

- Carbon nanotubes (CNTs) since been firstly discovered
by Iijima.

•

In:+ 1991- MWCNT

      + 1993 – SWCNT

Fig2. Descriptive structure of SWCNT and MWCNT

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1.INTRODUCTION
As seeing accouterments, SWCNTs and MWCNTs bear as p-type semiconductors.
In fact, trials have shown that NH3 donates about 0.04 electrons per patch to SWNTs,[14 ] while NO2 withdraws approxi-mately 0.1 electron per patch with a
binding energy of 0.8 eV.[15 ]

Fig3.1. Graphite structure made by graphene

Fig3.2. Describe how to roll graphene to form CNTs

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1.INTRODUCTION
Transistor and chemfet diagrams

Transistor

Chemfet

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CNT chemiresistor

Chemical gas sensors are made simply by incorporating excellent sensing nanomaterials onto a substrate with electrode plating, and their sensing
mechanism is based on the change in electrical resistance of the device caused by the interaction between the target gas and the nanomaterials

 

S = ×100%

The resistance of the gas sensors to target gas and air, respectively, is represented by
Rg and R0

Fig 5. Chemical resistance-type gas sensors

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CNT CHEMFET

As illustrated in Fig. 6, a chemical field-effect transistor (CHEMFET) employs an electric field to regulate the flow of drain current to the gate
terminal, which affects the conductivity between the drain and source terminals.

Fig 6. CHEMFET sensor. G: gate; S: source; D: drain; VG: gate bias potential; VSD: source-drain potential
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1.INTRODUCTION

Fig7. Electrical schematics of a CHEMIRESISTOR  and CHEMFET platform

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Table 2. Comparison between resistive-type gas sensors and FET based H2 gas sensors

Sensor type

Response time

Detection limit, ppm

Sensitivity, %

Temperature, °C

Ref.

Resistive-type

2-7 min

15-100

2-14

RT

[55  -57] 

FET-type

10s-2 min

5-10

50-85

50-300

[58  -60] 

RT is room temperature


2.REVIEW

H2 Gas Sensor

By using aerosol-ray printing base in
Pt nanos

NH3 Gas Sensor

Using reactive ion etching (RIE)
and thermal CVD method

NH3 gas sensor on polimer
Polimer
(m aminobenzen
Sunfunic acid)

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2.1 GENERAL PRINCIPLE OF PAINTING NANOPARTICLES INTO NANOCARBONES

Step 1

Step 2

Step 3

Step 4
.The gas sensor which is in

Preparation of carbon
nanotubes

• SWCNT
• MWCNT

SCNTs thin films were
Coating different types of

meal nano into CNTs

deposited on Si substrate by

the form of field-effect
transistors (FETs)

CDV method

Figure 2: Brief summary of the process of creating gas sensors on
CNTs is added metal Nanos
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2.1 Comparison of H2 gas sensors on Nanocarbone

2.1

R
O
S
N
E
S
S
A
H2 G
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●2.1 By using Aerosol-ray Printing
CONTENTS

 CNTs metal of nano Pt hybrids

 Material : SWCNT film

 Sensitivity: 4% ( 20ppm )

 It’s fabricated using aerosol-ray printing,
and then decorated with nano Pt

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The SWCNT powder was first treated
with acidwas first treated with acid

Thin film gas sensors
were coated on Si

Eliminate the catalysts and

The purrified SWCNT power was

carbonaceous impurities

dispersed in solution of EG and SDS

Implement with reduced reaction to

H2PtCl6·H2O was added into the

obtain hybrid Pt-SWCNT

mixture

Substrates with the ink.

Picture 2 : Processing of creating H2 gas sensor base on nanocacbon basis by an aerosol jet printing method
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2.2 Comparison of NH3 gas sensors on Nanocarbone

2.2

R
O
S
N
E
S
S
A
NH3 G

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2.2 By using (RIE) and thermal CVD method

MATERIAL

SENSITIVITY

SWCNTs network
decorated with anatase

[Nh3] =10 ppm

OPTIMAL TEMPERTURE
0
190 C

TiO2

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2.3 Comparison of Nh3 gas sensors on CNTs/Polymer Sensors

Some conducting polymers can bear like semiconductors.
 
This effect is believed to be caused by the charge transfer between gas motes
and the polymer or the polymer film’s lump.
 

There are volumetric changes of the matrix polymer can be formed
“ percolation threshold”. 

CNTs/Polymer Sensors

 
The conductive polymers have been used to functionalize CNTs.
 
The PANI-SWCNT network based gas sensors were highly sensitive to NH3,
higher than SWCNTs by more than 60 times.
 
A similar sensor based on poly(m-aminobenzene sulfonic acid)
 

Figure 3: The simple diagram depicting about  CNTs/Polymer Composites Gas Sensors

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3. APPLICATION

Household appliances
Microware oven equipment,

Medical devices
Heart rate gauge, ultrasound machine

Installed in enclosed houses for agricultural
production

heating oven, air conditioner

Factory
Automobile production
Detecting gas leaks to promptly handle

Agriculture

Automobile engines and equipment

Sensor Material
Solar panels, biomedical materials,..

incidents

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4. Conslution

Summary of gas
sensors

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5. References

Shen, Y., Yamazaki, T., Liu, Z., et al.: ‘Hydrogen sensing properties of Pd-doped SnO2 sputtered films with columnar nanostructures’, Thin Solid Films, 2009, 517, (21), pp. 6119–6123
Zhang, D., Wang, D., Zong, X., et al.: ‘High-performance QCM humidity sensor based on graphene oxide/tin oxide/polyaniline ternary nanocomposite prepared by in-situ oxidative polymerization

method’, Sens. Actuators B,
Chem., 2018, 262, pp. 531–541
Zhang, D., Wang, D., Zong, X., et al.: ‘High-performance QCM humidity sensor based on graphene oxide/tin oxide/polyaniline ternary nanocomposite prepared by in-situ oxidative polymerization
method’, Sens. Actuators B,
Chem., 2018, 262, pp. 531–541
Ren, X., Zhang, D., Wang, D., et al.: ‘Quartz crystal microbalance sensor for
humidity sensing based on layer-by-layer self-assembled PDDAC/graphene oxide film’, IEEE Sens. J., 2018, 18, (23), pp. 9471–9476
Rad, A.S., Shabestari, S.S., Jafari, S.A., et al.: ‘N-doped graphene as a
nanostructure adsorbent for carbon monoxide: DFT calculations’, Mol. Phys., 2016, 114, (11), pp. 1756–1762
Rad, A.S., Foukolaei, V.P.: ‘Density functional study of Al-doped graphene
nanostructure towards adsorption of CO, CO2 and H2O’, Synth. Met., 2015,
210, pp. 171–178
Dhar, N., Syed, N., Mohiuddin, M., et al.: ‘Exfoliation behavior of van der
Waals strings: case study of Bi2S3’, ACS Appl. Mater. Interfaces, 2018, 10,
(49), pp. 42603–42611

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