|Eny Kusrini||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424, Indonesia|
|Nandy Putra||Applied Heat Transfer Research Group, Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424, Indonesia|
|Agung Siswahyu||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424, Indonesia|
|Dewi Tristatini||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424, Indonesia|
|Wuwuh Wijang Prihandini|
|Muhammad Idrus Alhamid||Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424, Indonesia|
|Yoki Yulizar||Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Kampus Baru UI, Depok 16424, Indonesia|
|Anwar Usman||Department of Chemistry, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410, Brunei Darussalam|
To maintain the stability of nanofluid from precipitation and agglomeration, some methods such as ultrasonic vibration, adding surfactant, and controlling the pH value of the system have been studied. Herein, the preparation of titanium dioxide (TiO2)–water nanofluid, by using TiO2 nanoparticles (TiO2 NPs) and the cationic surfactant cetyltrimethylammonium bromide (CTAB), was investigated to determine the effects of the sequence method on the preparation of TiO2–water nanofluid, its thermal conductivity, its stability, and its temperature distribution. NPs can improve the efficiency of heat transfer fluids and improving the stability of colloidal systems. Some parameters were varied, including sonication times of 5, 10, and 30 minutes, variations of TiO2 loading in 1–8% volumetric loading, concentrations of CTAB (0.005–0.035 wt%), and pH at 8–12. The procedure sequences of 2 and 5 showed the distribution particle size of TiO2 nanoparticles in nanofluid had a narrow range (190.3–208.7 nm) compared to other sequence methods (611 nm–5.35 mm). The procedure sequence of 2 is following demineralized water (100 mL), 8% volumetric loading of TiO2 NPs, ultrasonication time of 10 min and CTAB of 3.2×10-3 M, while the procedure sequence of 5 is in the respective order of demineralized water (100 mL), 8% volumetric loading of TiO2 NPs, ultrasonication time of 10 min and pH at 8. The CTAB surfactant (0.029 wt%) had a greater influence on particle distribution in the nanofluid than the pH. The thermal conductivities of the nanofluid were characterized with TiO2 nanofluid as the working fluid. The experimental results showed a maximum of 21% thermal conductivity enhancement for 8% volumetric loading of TiO2 NPs at pH 8 and fourfold increase in critical micelle concentration (0.029 wt%) from CTAB. These findings offer the potential for preparing a stable TiO2–water nanofluid with a short ultrasonic time of 10 minutes. This process is a desirable and very useful to obtain a stable TiO2–water nanofluid with a short ultrasonic time for efficient process and low-cost nanofluid with high thermal conductivity and stability.
Cationic surfactant; Concentration of CTAB; Thermal conductivity; TiO2-water nanofluid; Ultrasonic time
The development of high-performance heat transfer fluids using nanoparticles (NPs) has been interesting to investigate in detail (Ahlatli et al., 2016). It is well known that nanofluid, a colloidal mixture produced from a base fluid and a nanoparticle, has valuable heat transfer applications and is among a new generation of heat transfer fluids that enhance thermal conductivity. Studies of various parameters (such as particle size, concentration, temperature, material type and base fluid type) to enhance heat transference have been performed (Putra et al., 2012; Yiamsawasd et al., 2012; Saleh et al., 2013; Ismay et al., 2013). NPs can improve the efficiency of heat transfer fluids (Zhou et al., 2012; Saleh et al., 2013), as their high surface energy makes them easy to coagulate and difficult to disperse in base fluids, improving the stability of colloidal systems (Zhou et al., 2012). The stability of colloidal suspensions of micro and nanosized particles is dependent on the surface force between particles (namely, the zeta potential) that is influenced by pH value (Ismay et al., 2013). Das et al. (2018) experimentally investigated the stability measurement of anatase- sodium dodecyl sulfate (SDS) and anatase-cetyltrimethylammonium bromide (CTAB) nanofluids, which had observable zeta potentials of -17.8 mV and -21.1 mV, respectively. Therefore, anatase-CTAB nano?uid was found to have marginally better stability than the anatase-SDS nano?uid.
The agglomeration of TiO2 NPs settles and clogs microchannels as well as decreasing the thermal conductivity of nanofluid (Yu & Xie, 2012; Ismay et al., 2013). Many investigations have been conducted to produce a more stable colloidal and suspension of nanofluid. To maintain the stability of nanofluid from precipitation and agglomeration, some methods (such as ultrasonic vibration, adding surfactant, and controlling the pH value of the system) have been reported (Duangthongsuk & Wongwises, 2009). A well-known and effective method to homogenize dispersed NPs in base fluids is adding surfactant (Jiang et al., 2003; Xie et al., 2003; Murshed et al. 2005; Zhou et al., 2012).
The effects of surfactants (such as CTAB, acetic acid (AA), oleic acid (OA), and SDS) on TiO2–water nanofluid have been studied and findings have shown that CTAB and AA provided stable suspensions (Das et al., 2016; Adiwibowo et al., 2018). The TiO2 solid fraction has been varied between 0.1–2.0% while temperatures have ranged from 20 to 60°C (Das et al., 2016). Murshed et al. (2005) reported enhanced thermal conductivity (up to 33%) for deionized water by adding TiO2 NPs (5% volume fraction). That being said, TiO2 NPs have also been reported as causing dye degradation (Rahman et al., 2018; Zulmajdi et al., 2019).
In a previous study, the cationic surfactant CTAB was investigated for its ability to break down particle agglomeration in a suspension and was found more effective than oleic acid (Murshed et al., 2005). However, the TiO2 nanofluid by ultrasonic process for 8 to 10 hours (Murshed et al., 2005). On the other hand, Duangthongsuk and Wongwises (2009) investigated the preparation of TiO2 nanofluid by using ultrasonic within 2 hours. As noted here that the time for preparation of TiO2 nanofluid is too long in the range 2 to 10 hours.
Therefore, to reduce the ultrasonic times in preparation of TiO2–water nanofluid during the ultrasound process, the proper mixing, stabilization and also dispersion of TiO2 NPs in water are very important to investigate for producing the stable of TiO2–water nanofluid. In this study, improving and increasing the thermal conductivity of TiO2–water nanofluid and the optimum thermal conductivity from TiO2–water nanofluid with short time sonication were studied. The effect of CTAB in TiO2–water nanofluid formulation and the effect of sequence preparation methods in growth of particle size in TiO2–water nanofluid were also studied in detail. The experimental results and theoretical predictions from the Maxwell (1873) and Bhattacharya et al. (2004) models were also compared.
This study was carried out to find a new method for preparing TiO2–water nanofluid with high thermal conductivity. The optimal conditions for preparing TiO2–water nanofluid were found to be an addition of 8% volume fraction of TiO2 NPs, an adjusted pH of 8, and a cationic surfactant of 0.0073–0.029 wt%. The best sequencing methods were obtained for sequence procedure 2 using demineralized water as a base fluid and an 8% volume fraction of TiO2 NPs, followed by a 10-minute sonication process and the addition of CTAB (0.029 wt%). These results have a great potential for improving the thermal conductivity of TiO2–water nanofluid, which can be applied as a heat transfer in heat pipes. In conclusion, the addition of CTAB surfactant into the nanofluid can be used to minimize NP aggregation and improve the dispersion behavior of nanofluid.
Adiwibowo, M.T., Ibadurrohman, M., Slamet, 2018. Synthesis of ZnO Nanoparticles and Their Nanofluid Stability in the Presence of a Palm Oil-based Primary Alkyl Sulphate Surfactant for Detergent Application. International Journal of Technology, Volume 9(2), pp. 307–316
Ahlatli, S., Mare, T., Estelle, P., Doner, N., 2016. Thermal Performance of Carbon Nanotube Nanofluids in Solar Microchannel Collectors: An Experimental Study. International Journal of Technology, Volume 7(2), pp. 219–226
Assael, M.J., Metaxa, I.N., Arvanitidis, J., Christofilos, D., Lioutas, C., 2005. Thermal Conductivity Enhancement in Aqueous Suspensions of Carbon Multi-walled and Double-walled Nanotubes in the Presence of Two Different Dispersants. International Journal of Thermophys, Volume 26(3), pp. 647–664
Bhattacharya, P., Saha, S.K., Yadav, A., Phelan, P.E., Prasher, R.S., 2004. Brownian Dynamics Simulation to Determine the Effective Thermal Conductivity of Nanofluid. Journal of Applied Physics, Volume 95(11), pp. 6492–6494
Das, P.K., Mallik, A.K., Ganguly, R., Santra, A.K., 2016. Synthesis and Characterization of TiO2–water Nanofluid with Different Surfactants. International Communications in Heat and Mass Transfer, Volume 75, pp. 341–348
Das, P.K., Mallik, A.K., Ganguly, R., Santra, A.K., 2018. Stability and Thermophysical Measurements of TiO2 (Anatase) Nano?uids with Different Surfactants. Journal of Molecular Liquids, Volume 254, pp. 98–107
Duangthongsuk, W., Wongwises, S., 2009. Measurements of Temperature-dependent Thermal and Viscosity of TiO2-water Nanofluid. Experimental Thermal and Fluid Science, Volume 33(4), pp. 706–714
Hong, T.K., Yang, H.S, Choi, C.J., 2005. Study of the Enhanced Thermal Conductivity of Fe Nanofluids. Journal of Applied Physics, Volume 97(6), pp. 1–4
Ismay, M.J.L., Doroodchi, E., Moghtaderi, B., 2013. Effects of Colloidal Properties on Sensible Heat Transfer in Water-based Titania Nanofluid. Chemical Engineering Research and Design, Volume 91(3), pp. 426–436
Jayasree, T.K., Predeep, P., Agarwal, R., Saxena, N.S., 2006. Thermal Conductivity and Thermal Diffusivity of Thermoplastic Elastomeric Blends of Styrene Butadiene Rubber/High Density Polyethylene: Effect of Blend Ratio and Dynamic Crosslinking. Trends in Applied Sciences Research, Volume 1(3), pp. 278–291
Jiang, L., Gao, L., Sun J., 2003. Production of Aqueous Colloidal Dispersions of Carbon Nanotubes. Journal of Colloid Interface Science, Volume 260(1), pp. 89–94
Jin, H., Xianju, W., Qiong, L., Xueyi Yunjin, W., Liming, Z.L., 2009. Influence of pH on the Stability Characteristics of Nanofluid. In: Symposium on Photonics and Optoelectronics, pp. 1–4
Leong, K.C., Yang, C., Murshed, S.M.S., 2006. A Model for the Thermal Conductivity of Nanofluid—The Effect of Interfacial Layer. Journal of Nanoparticles Resource, Volume 8(2), pp. 245–254
Li, X.F., Zhu, D.S., Wang, X.J., Wang, N., Gao, J.W., Li, H., 2008. Thermal Conductivity Enhancement Dependent pH and Chemical Surfactant for Cu–H2O Nanofluid. Thermochimica Acta, Volume 469(1–2), pp. 98–103
Maxwell, J.C., 1873. A Treatise on Electricity and Magnetism. Clarendon Press, Oxford, UK
Murshed, S.M.S., Leong, K.C., Yang, C., 2005. Enhanced Thermal Conductivity of TiO2–water-based Nanofluid. International Journal of Thermal Sciences, Volume 44(4), pp. 367–373
Murshed, S.M.S., Leong, K.C., Yang, C., 2008. Investigations of Thermal Conductivity and Viscosity of Nanofluid. International Journal of Thermal Sciences, Volume 47(5), pp. 560–568
Prasher, R., Phelan, P.E., Bhattacharya, P., 2006. Effect of Aggregation Kinetics on the Thermal Conductivity of Nanoscale Colloidal Solutions (Nanofluid). Nano Letters, Volume 6(7), pp. 1529–1534
Putra, N., Septiadi, W.N., Rahman, H., Irwansyah, R., 2012. Thermal Performance of Screen Mesh Wick Heat Pipes with Nanofluid. Experimental Thermal and Fluid Science, Volume 40, pp. 10–17
Rahman, A., Nurjayadi, M., Wartilah, R., Kusrini, E., Prasetyanto, E.A., Degermenci, V., 2018. Enhanced Activity of TiO2/Natural Zeolite Composite for Degradation of Methyl Orange under Visible Light Irradiation. International Journal of Technology, Volume 9(6), pp. 1159–1167
Saleh, R., Putra, N., Prakoso, S.P., Septiadi, W.N., 2013. Experimental Investigation of Thermal Conductivity and Heat Pipe Thermal Performance of ZnO Nanofluid. International Journal of Thermal Sciences, Volume 63, pp. 125–132
Saleh, R., Putra, N., Wibowo, R.E., Septiadi, W.N., Prakoso, S.P., 2014. Titanium Dioxide Nanofluid for Heat Transfer Applications. Experimental Thermal and Fluid Science, Volume 52, pp. 19–29
Sonawane, S.S., Khedkar, R.S., Wasewar, K.L., 2015. Effect of Sonication Time on Enhancement of Effective Thermal Conductivity of Nano TiO2–water, Ethylene Glycol, and Paraffin Oil Nanofluid and Models Comparisons. Journal of Experimental Nanoscience, Volume 10(4), pp. 310–322
Vasiliev, L.L., 2005. Review Heat Pipes in Modern Heat Exchangers. Applied Thermal Engineering, Volume 25, pp. 1–19
Wang, X.J., Zhu, D.S., Yang, S., 2009. Investigation of pH and SDBS on Enhancement of Thermal Conductivity in Nanofluid. Chemical Physics Letters, Volume 470(1–3), pp. 107–111
Xie, H.Q., Xi, T.G., Wang, J.C., 2003. Study on the Mechanism of Heat Conduction in Nanofluid Medium. Acta Physica Sinica, Volume 52(6), pp. 1444–1449
Yiamsawasd, T., Dalkilic, A.S., Wongwises, S., 2012. Measurement of the Thermal Conductivity of Titania and Alumina Nanofluid. Thermochimia Acta, Volume 545, pp. 48–56
Yu, W., Xie, H.A., 2012. Review on Nanofluid: Preparation, Stability Mechanisms, and Applications. Journal of Nanomaterials, Volume 2012, pp. 1–17
Zhen-Jian, H., Chun-Hua, T., Xu-Guang H., 2010. Determination of Surfactant CMC based on the Fiber Refractive Index Sensor Principle. Acta Physics Chimica Sinica, Volume 26, pp. 1271–1276
Zhou, M., Xia, G., Li, J., Chai, L., Zhou, L., 2012. Analysis of Factors Influencing Thermal Conductivity and Viscosity in Different Kinds of Surfactant Solutions. Experimental Thermal and Fluid Science, Volume 36, pp. 22–29
Zhu, D., Li, X., Wang, N., Wang, X., Gao, J., Li, H., 2008. A Dispersion Behavior and Thermal Conductivity Characteristics of Al2O3–H2O Nanofluid. Current Applied Physics, Volume 9(1), pp. 131–139
Zulmajdi, S.L.N., Zamri, N.I.I., Mahadi, A.H., Rosli, M.Y.H., Ja’afar, F., Yasin, H.M., Kusrini, E., Hobley, J., Usman, A., 2019. Sol-gel Preparation of Different Crystalline Phases of TiO2 Nanoparticles for Photocatalytic Degradation of Methylene Blue in Aqueous Solution. American Journal of Nanomaterials, Volume 7(1), pp. 39-45