Optimisation of charge ratios for ball milling synthesis: agglomeration and refinement of coconut shells

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Sefiu Adekunle Bello Johnson Olumuyiwa Agunsoye Jeleel Adekunle Adebisi Suleiman Bolaji Hassan


Agglomeration is an attraction of fine particles for one another due to their high surface energy, leading to formation of particle colonies known as agglomerates. When a polymeric or metallic matrix is reinforced with particles, agglomerates usually create regions of discontinuity or weak particle adhesion within the matrix and degrade mechanical properties of the resulting composites. In ball-milling synthesis of nanoparticles, formation of agglomerates can be controlled through optimisation of milling parameters. In this study, coconut shell (lignocellulosic) nanoparticles were synthesised by varying the charge ratios from 2.5 to 40 at constant milling duration (70 hours), speed in terms of drum/vial rotation (194 revolution per minute) and ball sizes (5- 60 mm). Assessment of the effects of charge ratios (CRs) on the morphologies and particles sizes of uncarbonised coconut shell nanoparticles (UCSnp) was studied. The synthesised UCSnp were characterised using electron microscopy and X-ray diffractometry (XRD). The results showed various morphologies and orientations of UCSnp with changes in the CRs. Size determination using XRD and SEM revealed a reduction in particle size as the CR increased up to a value of 10. At higher CRs, further reduction in the average particle size was not observable.   This could be linked to a balance between particle refinement and agglomeration at these higher CRs. Although particle agglomeration was apparent above CR values of 10, sizes of the UCSnp obtained above this CRs were much smaller than the initial size (37 μm) of the coconut shell precursor particles. This affirmed the ball milling synthesis as a particle refinement process, but not a coarsening/agglomeration process. The results obtained from statistical analyses show agreement with experimental results.


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How to Cite
Bello, S., Agunsoye, J., Adebisi, J., & Hassan, S. (2018). Optimisation of charge ratios for ball milling synthesis: agglomeration and refinement of coconut shells. Engineering and Applied Science Research, 45(4), 262-272. Retrieved from https://www.tci-thaijo.org/index.php/easr/article/view/109771


[1] Moreno R, Ferrari B. Nanoparticles dispersion and the effect of related parameters in the EPD kinetics. In: Dickerson J, Boccaccini A, editors. Electrophoretic Deposition of Nanomaterials. Nanostructure Science and Technology. New York: Springer; 2012. p. 73-128.

[2] Lowndes DH. Nanoscale science, engineering and technology research directions. USA: Oak Ridge National Laboratory; 1999.

[3] Pokropivny V, Lohmus R, Hussainova I, Pokropivny A, Vlassov S. Introduction to nanomaterials and nanotechnology. Estonia: Tartu University Press; 2007.

[4] Aïcha H, Marco C, Duncan A. Transmission electron microscopy and diffraction. Switzerland: Centre interdisciplinaire de Microscopie Electronique (CIME), Photovoltaics and Thin-Film Electronics Laboratory (PV-lab); [date unknown].

[5] FEI COMPANY. All you wanted to know about Electron Microscopy. USA: FEI COMPANY; [date unknown].

[6] Mogilatenko A, Kirmse H. Transmission electron microscopy in materials science. Berlin: Humboldt-Universität zu Berlin; [date unknown].

[7] Zinin P. GG 711: Advanced techniques in geophysics and materials science HIGP. USA: University of Hawaii; [date unknown].

[8] Echin P. Handbook of sample preparation for scanning electron microscopy and x-ray microanalysis. USA: Springer; 2009.

[9] University of Babylon. Chapter 3: Transmission electron Microscopy. Iraq: University of Babylon; [date unknown]. p. 21-42.

[10] EA Group. Aberration corrected scanning transmission electron microscopy (AC-STEM) services. San Diego: Evans Analytical Group; 2014.

[11] Ma H, Shieh KJ, Qiao TX. Study of transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Nat Sci. 2006;4(3):14-22.

[12] Voutou B, Stefanaki E. Electron microscopy: The Basics. Physics of Advanced Materials Winter School. 2008:1-11.

[13] Wang C, Liu Y. EMA 6518: Transmission Electron Microscopy. USA: Advanced Materials Engineering Research Institute (AMERI). [date unknown].

[14] Wang D. Transmission Electron Microscopy. USA: Swagelok Centre for Surface Analysis of Materials, Case Western Reserve University; 2016.

[15] Wang ZL. Transmission electron microscopy of Shape-controlled nanocrystals and their assemblies. J Phys Chem B. 2000;104(6):1153-75.

[16] Wang ZL. New development in transmission electron microscopy for nanotechnology. Adv Mater. 2003;15(18):1498-514.

[17] Zheng JG. What can electrons do?. USA: EPIC/NUANCE Center, Northwestern University; 2006.

[18] Bello SA. Development and characterisation of epoxy-aluminium-coconut shell particulate hybrid nanocomposites for automobile applications. Nigeria: Department of Metallurgical and Materials Engineering, University of Lagos; 2017.

[19] Bello SA, Agunsoye JO, Hassan SB, Zebase Kana MG, Raheem IA. Epoxy resin based composites, mechanical and tribological properties: a review. Tribology in Industry. 2015;37(4):500-24.

[20] Sarki J, Hassan SB, Aigbodion VS, Oghenevweta JE. Potential of using coconut shell particle fillers in eco-composite materials. J Alloy Comp. 2011;509(5): 2381-5.

[21] Knieke C, Steinborn C, Romeis S, Peukert W, Breitung-Faes S, Kwade A. Nanoparticle production with stirred-media mills: opportunities and limits. Chem Eng Tech. 2010;33(9):1401-11.

[22] Prasad Yadav T, Manohar Yadav R, Pratap Singh D. Mechanical milling: a top down approach for the synthesis of nanomaterials and nanocomposites. Nanoscience and Nanotechnology. 2012;2(3):22-48.

[23] Sommer M, Stenger F, Peukert W, Wagner NJ. Agglomeration and breakage of nanoparticles in stirred media mills—a comparison of different methods and models. Chem Eng Sci. 2006;61(1):135-48.

[24] Breitung-Faes S, Kwade A. Nano particle production in high-power-density mills. Chem Eng Res Des. 2008; 86(4):390-4.

[25] Essl F, Bruhn J, Janssen R, Claussen N. Wet milling of Al-containing powder mixtures as precursor materials for reaction bonding of alumina (RBAO) and reaction sintering of aluminium-aluminide alloys (3A). Mater Chem Phys. 1999; 61(1):69-77.

[26] Bello SA, Agunsoye JO, Hassan SB. Synthesis of coconut shell nanoparticles via a top down approach: assessment of milling duration on the particle sizes and morphologies of coconut shell nanoparticles. Mater Lett. 2015;159:514-9.

[27] Agunsoye JO, Aigbodion VS. Bagasse Filled Recycled Polyethylene Bio-composites: Morphological and Mechanical Properties Study. Results in Physics. 2013;3:187-94.

[28] Atuanya CU, Edokpia RO, Aigbodion VS. The physio-mechanical properties of recycled low density polyethylene (RLDPE)/bean pod ash particulate composites. Results in Physics. 2014;4:88-95.

[29] Bello SA, Hassan SB, Agunsoye JO, Kana MGZ, Raheem IA. Synthesis of uncarbonised coconut shell nanoparticles: characterisation and particle size determination. Tribology in Industry. 2015;37:257-63.

[30] Bello SA, Agunsoye JO, Adebisi JA, Kolawole FO, Suleiman BH. Physical properties of coconut shell nanoparticles. Kathmandu University Journal of Science, Engineering and Technology. 2016; 12(1):63-79.

[31] Agunsoye JO, Talabi SI, Bello SA, Awe IO. The effects of cocos nucifera (coconut shell) on the mechanical and tribological properties of recycled waste aluminium can composites. Tribology in Industry. 2014;36(2):155-62.

[32] Chauruka SR, Hassanpour A, Brydson R, Roberts KJ, Ghadiri M, Stitt H. Effect of mill type on the size reduction and phase transformation of gamma alumina. Chem Eng Sci. 2015;134:774-83.

[33] Liu T, Shen H, Wang C, Chou W. Structure evolution of Y2O3 nanoparticle/Fe composite during mechanical milling and annealing. Progr Nat Sci. 2013; 23(4):434-9.

[34] Qu Y, Luo H, Li H, Xu J. Comparison on structural modification of industrial lignin by wet ball milling and ionic liquid pretreatment. Biotechnology Reports. 2015;6:1-7.

[35] Yang F, Yan G, Wang QY, Xiong XM, Li SQ, Liu GQ, et al. The effect of high-energy ball milling on the microstructure and properties of ti-doped mgb2 bulks and wires. Physics Procedia. 2015;65:157-60.

[36] Hassan SB, Agunsoye JO, Bello SA. Characterization of coconut shell nanoparticles using electron microscopes. Proceedings of 10th UNILAG Annual Research Conference and Fair; 2015 Nov 24-26; Lagos , Nigeria. Lagos: University of lagos; 2015. p. 221-5.

[37] Agunsoye JO, Bello SA, Bello L, Idehenre MM. Assessment of mechanical and wear properties of epoxy based hybrid composites. Adv Produc Engineer Manag. 2016;11(1):5-14.

[38] Asuke F, Aigbodion VS, Abdulwahab M, Fayomi OSI, Popoola API, Nwoyi CI, et al. Effects of bone particle on the properties and microstructure of polypropylene/bone ash particulate composites. Results in Physics. 2012;2:135-41.

[39] Hanna W, Maung K, El-Danaf EA, Almajid AA, Soliman MS, Mohamed FA. Nanocrystalline 6061 Al powder fabricated by cryogenic milling and consolidated via high frequency induction heat sintering. Advances in Materials Science and Engineering. 2014;2014:1-9.

[40] Varol T, Canakci A, Yalcin ED. Fabrication of nanoSiC-reinforced Al2024 matrix composites by a novel production method. Arab J Sci Eng. 2016;42(5):1751-64.

[41] Wolff MFH, Antonyuk S, Heinrich S, Schneider GA. Attritor-milling of poly(amide imide) suspensions. Particuology. 2014;17:92-6.

[42] Bello SA, Agunsoye JO, Adebisi JA, Anyanwu JE, Bamigbaiye AA, Hassan SB. Potential of Carbonised Coconut Shell as a Ball-Milling Interface for Synthesis of Aluminium (1xxx) Nanoparticles. ANNALS of Faculty Engineering Hunedoara–International Journal of Engineering. 2017;15:149-57.

[43] Bello SA, Agunsoye JO, Adebisi JA, Kolawole FO, Raji NK, Hassan SB. Quasi crystal al (1xxx)/carbonised coconut shell nanoparticles: synthesis and characterisation. MRS Advances. 2018:1-13.

[44] Agunsoye JO, Bello SA, Adetola LO. Experimental investigation and theoretical prediction on tensile properties of particulate reinforced polymeric composites. Journal of King Saud University - Engineering Sciences. In press 2017.

[45] Atuanya CU, Aigbodion VS, Nwigbo SC. Experimental study of the thermal and wear properties of recycled polyethylene/breadfruit seed hull ash particulate composites. Mater Des. 2014;53:65-73.