RHEOLOGICAL BEHAVIOUR OF ETHYLENE GLYCOL BASED TITANIA NANOFLUIDS KHAIRUNNISA BINTI ABDUL HALIM A project report submitted in partial fulfilment of the requirements for the award of the degree of Bachelor of Engineering (Chemical) Faculty of Chemical Engineering Universiti Teknologi Malaysia JANUARY 2013
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RHEOLOGICAL BEHAVIOUR OF ETHYLENE GLYCOL BASED TITANIA
NANOFLUIDS
KHAIRUNNISA BINTI ABDUL HALIM
A project report submitted in partial fulfilment of the
requirements for the award of the degree of
Bachelor of Engineering (Chemical)
Faculty of Chemical Engineering
Universiti Teknologi Malaysia
JANUARY 2013
v
ABSTRACT
The purpose of this study is to investigate the rheological behaviour of
ethylene glycol (EG) based titania nanofluids. Generally, rheology is the study of
the deformation and flow of the matter. Nanofluids are dilute liquid suspensions of
nanoparticles which at least one critical dimension smaller than ~100nm in which is
used to enhance the thermal heat coefficient. Nanofluids have better heat
characteristics and have larger thermal conductivities compared to the base fluids,
however, the thermal behaviour of nanofluids correlates well with the rheological
behaviour of the nanofluids. This indicates the significance of studying the rheology
of nanofluids. In order to study the rheology of nanofluids, a set of stable nanofluids
have to be prepared with several different concentration and pH value. Then the
characterization of nanofluids will be done in terms of stability and viscosity; at
different temperature (27 ⁰C, 40 ⁰C, 50 ⁰C and 60 ⁰C); and concentration of titania
nanoparticles. Later the viscosity of the nanofluids were analysed to understand the
rheology. Titania nanoparticles were dispersed in the EG as the base fluid by two-
step method. A surfactant, Sodium Lauryl Sulphate (SLS) was used to stabilize the
nanofluids. SLS surfactant helps to reduce agglomeration in the titania nanofluids.
From the observation, the samples were stable for not more than a week. For both
pH of titania nanofluids (pH 3 and pH 11), the viscosity was increasing with the
increment of weight percentages and decrease with the temperature. Furthermore,
the shear stress decreases with the temperature and increases with weight percentage.
vi
ABSTRAK
Tujuan kajian ini adalah untuk menyiasat kelakuan rheologi bendalir-
nano titania berasaskan glikol etilena (EG). Secara umumnya, rheologi adalah
kajian terhadap perubahan dan aliran sesuatu jisim. Bendalir-nano adalah
cairan cecair nanopartikel yang mengandungi sekurang-kurangnya satu
dimensi kritikal yang lebih kecil daripada ~100nm yang mana digunakan
untuk meningkatkan pekali haba terma. Bendalir-nano mempunyai sifat-sifat
haba yang lebih baik dan mempunyai pekali terma yang lebih besar jika
dibandingkan dengan bendalir asas. Walau bagaimanapun, perlakuan terma
bersangkut paut dengan perlakuan rheologi bagi cecair nano. Hal ini
menerangkan kepentingan kajian terhadap perlakuan rheologi cecair nano.
Untuk menyiasat perlakuan rheologi tersebut, satu set sampel titania-EG
cecair nano perlu disediakan dengan beberapa kepekatan titania nano-partikel
yang berbeza, pH dan suhu yang berbeza (27 ⁰C, 40 ⁰C, 50 ⁰C and 60 ⁰C).
Kemudian, pencirian cecair nano dilakukan dalam bentuk kestabilan dan
kelikatan; pada suhu dan kepekatan berbeza. Partikel-nano dari titania telah
diserakkan di dalam EG sebagai cecair dasar oleh kaedah dua langkah. Satu
bahan penyelerak, Sodium Lauril Sulfat (SLS) telah digunakan untuk
menstabilkan bendalir-nano. SLS membantu untuk mengurangkan
penumpuan dalam bendalir-nano titania. Melalui pemerhatian yang
dijalankan, bendalir-nano dari cairan EG stabil hanya untuk tidak lebih dari
satu minggu. Bagi kedua-dua nilai pH untuk bendalir-nano titania (pH 3 dan
pH 11), kelikatan telah meningkat dengan kenaikan peratusan berat dan
penurunan dengan. Tambahan pula, tegasan ricih berkurangan dengan suhu
dan meningkat dengan peratusan berat.
vii
TABLE OF CONTENT
CHAPTER TITLE
DECLARATION
PAGE
ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENT vii
LIST OF TABLES x
LIST OF FIGURES xi
LIST OF ABBREVIATIONS xv
LIST OF SYMBOLS xvii
LIST OF APPENDIX xviii
1 INTRODUCTION
1.1 Background of Study 1
1.2 Problem Statement 4
1.3 Objective of Study 6
1.4 Scope of Study 6
1.5 Significant of Study 6
2 LITERATURE REVIEW
2.1 Rheological Behavior of Nanofluids 8
2.2 Experimentally Measured Rheological Data for
Nanofluids
11
viii
2.2.1 Effects of Newtonian and non-Newtonian
Behaviour
12
2.2.2 Effects of High Shear Viscosity 14
2.2.3 Effects of Shearing Time 18
2.3 Nanofluids 20
2.3.1 Properties of Nanofluids 20
2.3.2 Preparation of Nanofluids 21
2.3.3 Addition of Surfactant 22
2.3.4 Effects of Base Fluids on the Heat Transfer
Properties
23
2.4 Viscosity of Nanofluids 24
2.5 Factors that Affects Viscosity of the Nanofluids 25
2.5.1 Temperature 25
2.5.2 Weight Fraction 28
2.5.3 Particle Size and Shape 30
2.6 Stability Investigation 30
3 METHODOLOGY
3.1 Materials 33
3.2 Experimental Procedures 34
3.2.1 Preparation of Nanofluids 34
3.2.2 Stability Investigation 36
3.2.3 Viscosity Measurement 36
3.3 Process Flow Diagram 37
4 RESULT AND DISCUSSION
4.1 Introduction 39
4.2 Result and Discussion 39
4.2.1 Synthesis of EG based Titania Nanofluids 40
4.2.1 Stability Investigation 41
4.2.3 Factors that Affected Viscosity of Nanofluids 44
4.2.3.1 Wt% of TiO2 Nanoparticles 44
ix
4.2.3.2 Temperature 58
4.2.4 Rheological Behavior of EG based Titania
Nanofluids 65
4.2.4.1 Effects of Newtonian and non-
Newtonian Behavior 65
4.2.4.2 Effects of Shearing Time 71
5 CONCLUSIONS AND RECOMMENDATIONS 75
REFERENCES 77
APPENDIX 89
REFERENCES
Abdulagatov, M. I. and Azizov, N. D. (2006). Experimental Study of the Effect of
Temperature, Pressure and Concentration on the Viscosity of Aqueous NaBr
Solutions. Journal of Solution Chemistry. 35(5): 705–738.
Aladag, B., Halefadl, S., Doner, N., Mare, T., Duret, S., and Estelle, P. (2012).
Experimental Investigations of the Viscosity of Nanofluids at Low
Temperatures. Applied Energy. (97): 876-880.
Alias, H., and Ho., P. W. (2009). Synthesis and Flow Behaviour of Carbon