INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XIII, Issue X, October 2024
www.ijltemas.in Page 93
Characterization of Palm Kernel Shell Ash Nanoparticles as Coating
Material for High Temperature Applications.
EA Abhulimen,
TN Guma, N Achara
Mechanical Engineering Department, Nigerian Defence Academy, Kaduna, Nigeria
DOI : https://doi.org/10.51583/IJLTEMAS.2024.131012
Received: 22 October 2024; Accepted: 30 October 2024; Published: 07 November 2024
Abstract: The kernel shell of oil palm (Elaesis guineensis) was milled, calcinated and synthesized into nanoparticles (np) with a view to
analyzing and ascertaining its high temperature strength. The synthesized particles were characterized to reveal their elemental composition
and temperature of maximal decomposition/destruction, with the solgel method employed in the nanoparticle synthesis. The morphology
of the Palm Kernel Shell Ash nanoparticles (PKSAnp) viewed from Transmission Electron Microscope (TEM) revealed that the
nanoparticles were solid in nature but vary in sizes with some spherical particles visible, and an average particle size found to be 39.17nm.
The Electron Dispersion Spectroscope (EDS) result shows that only elements such as C, O, Si, Al, Ca, and K are present in the PKSAnp,
with silicon (Si) found to be dominant. Oxides of Silicon and Aluminum (SiO
2
and Al
2
O
3
) were identified as the key chemical compounds
in PKSAnp from X-Ray Fluorescence (XRF) investigation whereas K
2
O, CaO and Na
2
O were among the other oxides present in traces.
The Thermogravimetric analysis (TGA) curve shows a lower proportion of breakdown and a residual weight stability at temperatures above
1000
o
C, coinciding with the silica content in PKSAnp. This is comparable and consistent with known high temperature coating materials
in previous literature.
Key words: Characterization, Palm Kernel Shell, Nanoparticles, Coating, High Temperature
I. Introduction
The Palm Kernel Shell (PKS) is produced by a species of palm, commonly called the Africa oil palm (Elaeis guineensis). It is the hard part
that enclosed the nut of palm kernel fruit and the shell parts obtained as residual waste after crushing and removal of nut in the palm oil
mill during the extraction of kernel. The use of Elaeis guineensis leaves extract as corrosion inhibitor [1], is an established indication that
its shell could yield positive result in the management of hot corrosion. The palm kernel shell has estimated value of about 34.5% of a
single ripe, fresh fruit [2][3], where in the year 2001 alone, the estimated value of 3.06 million metric tons was produced by Indonesia and
Malaysia. From this estimated value of 34.5% PKS from a single fruit, it could be established that the disposal of these biomass wastes
will continue to pose major environmental problems [4]. Coating on the other hand refers to a covering applied to the surface of an object,
usually the substrate for either a decorative purpose, functional purpose or both [5]. Coatings such as Paints and lacquers mostly serve dual
purposes of protection and decoration on the substrate. Some artists’ paints are only for decoration whereas the paint on large industrial
pipes is for corrosion prevention and identification. Functional coatings may be applied to change the surface properties of a substrate,
such as adhesion, wettability, corrosion resistance, or wear resistance [6]. Thermal barrier coatings (TBC) are high-temperature coating
systems for metallic surfaces which serve to protect the parts by limiting the thermal exposure of structural components and thus extending
their lifetime. A thin coating or thick layer produced either by metallurgical, mechanical, physical, or chemical means alters the surface
of a manufactured item to achieve certain desired property [7]. The process often results in improved appearance, adhesion, corrosion
resistance, tarnishes resistance, chemical resistance and wear resistance. The use of protective thermal barrier and bond coatings has
resulted in significant improvements in superalloy performance.
II. Materials, Equipment and Methods
A. Materials
The materials used in the course of this work include; Palm kernel shell sourced from Ohordua in Edo State, Nigeria, De-ionized water,
Distilled water, Hydrochloric Acid (HCl), Sodium Hydroxide (NaOH), ethanol, Zinc Sulphate ZnSO
4
, and a Cationic Surfactant (N, N-
dimethyldodecylamine).
B. Equipment
The Equipment used include; Erlenmeyer flask, copper grid, Metal mould, hydraulic press, Rockwell hardness, grinding and polishing
machine, TEM (Jeol, JSM2010), graphite crucible, Carbolite electric resistance furnace ASAP 2020 Micromeritics surface area analyzer,
PANalytical X-PERT PRO diffractometer, Nanoparticle size analyzer Model: HORIBA LB 550, Perkin Elmer spectrum 100 FT – IR
spectrometer, pulverizing machine, X-ray diffraction machine (XRD), Fourier transform infrared spectrometry (FTIR), Q50
thermogravimetric analyzer, Perkin Elmer differential scanning calorimeter (DSC7), magnetic stirrer, rectifier
C. Methods
The methods employed in the research are as enumerated below:
INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XIII, Issue X, October 2024
www.ijltemas.in Page 94
1) Palm Kernel Shell Ash Processing: The palm kernel shell so sourced (Figure 1: The PKS) was cleaned and dried and the dry PKS
were in a high-intensity ball milling machine, crushed and milled as in Figure 2: PKS undergoing crushing, into powdered particles
which were placed in a graphite crucible and heated to 1200°C in a Carbolite electric resistance furnace to create Palm Kernel
Shell Ash (PKSA).
Figure 1: The PKS
Figure 2: PKS undergoing crushing
2) PKSA Nanoparticles Production: The Palm Kernel Shell Ash nanoparticles (PKSAnp) utilized in this study were made using the
sol gel technique. 50 grams of NaOH was dissolved in 1dm
3
of water to treat the PKSA particles. This sodium hydroxide solution
was added to the PKSA. The fluid was covered with Erlenmeyer flask and agitate for two hours. The solution was then filtered
and the carbon residue removed. The filtrate was cooled to room temperature. With the addition of HCl, it was stirred continually
until the pH reached 7, after which it was aged for 8hrs at 65
0
C to produce gel. When the gel layers had formed in the solution,
the stirring was halted. The collected layers were centrifuged at 6000g for 5mins to separate the pellets which were washed with
distilled water and ethanol solution. The filtered pellets were then dried in a professional oven for 30mins at 80
0
C and then ground
into powder using a mortar and pestle.
D. Characterization of the PKSA Nanoparticles
1) Transmission Electron Microscopy (TEM): TEM (Jeol, JSM2010) (see Figure 3.3) was used to analyze the particle size and shape
of the generated nanoparticles. 10mg sample of nanoparticles was sonicated in 5ml of isopropyl alcohol for 3hrs. Using a dropper,
the sample solution was applied to the copper grid that had been coated with carbon (The sample chamber was emptied before
the copper grid was added to the apparatus) and left to cure at room temperature. The number averaged particle radius was used
to calculate the particle size on the presumption that the particle was spherical and the sample was photographed after being
scanned along a 200kV electron beam on the sample placed on a carbon-coated copper grid in a vacuum operated in the 10
-
9
Torr range at 25
0
maximum tilt angle in goniometer with single and double tilt stages [8].
2) X-Ray Diffractometer (XRD) Analysis: The X-ray diffraction (XRD) patterns of the PKSAnp samples were acquired using a Cu
K radiation-powered XRD diffractometer, LR39487C (40kV, 40mA). made by XPertPro PANalytical. The small angle stepwise
rise was 0.01
0
across the 1 to 8
0
range, and the broad angle stepwise increase was 1
0
, 2 min
-1
over the 8 to 90
0
range, respectively.
Using the Scherrer’s equation[9],
D
Cos
K
= (2.1)
INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XIII, Issue X, October 2024
www.ijltemas.in Page 95
Where θ is the angle between the incident and diffracted beams (degree), β; is the line broadening at half the maximum intensity,
after subtracting the instrumental line broadening (rad.), D; the particle size of the sample (nm), λ the is wavelength of the X-ray
and K is a dimensionless shape factor, with a value close to unity; the samples' particle size was estimated.
3) Thermal Analysis: Using a TA Instrument TGA Q50 thermogravimetric analyzer, the thermal decomposition was measured in
terms of global mass loss. The mass loss was measured as a function of temperature with a precision of 0.1. The samples were
placed loosely in an open sample pan of 6.4mm diameter and 3.2mm depth with an initial sample weight of 8-10mg. Using a
heating rate of 10
0
C/min, the temperature was controlled to rise from room temperature (25
0
C) to 1000
0
C. At room temperature
and atmospheric pressure, high quality Argon was constantly pumped into the furnace at a flow rate of 60ml/min to purge the
furnace for 30mins before the commencement of each run to create an inert atmosphere and ward off any unintended oxidative
breakdown. With the TA Instruments' universal analysis 2000 software, the TG and DTA curves were derived. In addition, a
Perkin Elmer differential scanning calorimeter (DSC7) was used to accurately measure the melting points, glass transitions, and
heats of fusion. The typical temperature range was from 10 to 400
0
C and the temperature scale was calibrated using a two-point
calibration, measuring the onset temperatures of indium and zinc standards. The enthalpy scale was also calibrated using the
observed delta-H from an accurately known amount of indium[10].
4) Composition analysis: The generated nanoparticles' elements were analyzed using a Mini Pal small Energy Dispersive X-Ray
Fluorescence Spectrometer (EDXRF) with a computer running the specialized Mini Pal analysis software serving as the system's
controller. EDXRF spectrometer is the elemental analysis tool of choice, for many applications, in that it is smaller, simpler in
design and relatively cost effective in operation. It has a very high-count rates and comparatively high energy resolution. Samples
were provided as thin films on a reflective carrier and the primary beam struck the sample at a glancing angle of less than
0.1
0
under total-reflection conditions. Silicon drift detectors measured the energy of an incoming photon by the amount of
ionization it produced in the detector material and a transversal field was generated by a series of ring electrodes that forces
charge carriers to ‘drift’ to a small collection electrode. The calibration was performed by a set of elemental and multi elemental
standards whereas the analysis and quantification were performed by the addition of a suitable Internal Standard (IS) to the
sample. The elemental concentration was determined based on the analytical signals of the analyte and their respective
instrumental sensitivities [11].
III. Results And Discussion
The physical, morphology, chemical composition, and thermal characteristics of the PKSA nanoparticles are as discussed and the findings
of the characterization experiments provided below;
A. TEM Image of the Palm kernel Shell Nanoparticles (PKSAnp)
Figure 3: morphology of the PKSAnp and Fig. 4 depict the morphology of the PKSAnp as seen by TEM. It was discovered that the
nanoparticles were solid in nature but varied in size. Particles with a spherical form were also visible. The average particle sizes obtained
are 39.07np. It was noted that C, O, Si, Al, Ca, and K were found in the EDS as the PKSAnp underwent micro-analysis. The higher peak
of silicon (Si) in figure 3.2 was caused by silica, which makes up the majority of PKSAnp.
Figure 3: morphology of the PKSAnp
Figure 4: TEM/EDS of the PKSAnp
INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XIII, Issue X, October 2024
www.ijltemas.in Page 96
B. X-ray Fluorescence (XRF) Analysis of the PKSA Nanoparticles
Table 1 displays the PKSAnp's XRF chemical composition. SiO
2
and Al
2
O
3
were identified as key components of the PKSAnp by XRF
investigation with K
2
O, CaO and Na
2
O being among the other oxides that were shown to be present in traces.
Table 1: Composition of the PKSA nanoparticles
Compounds
SiO
2
Al
2
O
3
Fe
2
O
3
CaO
MgO
Na
2
O
K
2
O
LOI
PKSAnp
83.17
8.67
0.9
2.32
1.3
0.21
0.2
2.01
C. XRD Analysis of the Palm Kernel Shell Nanoparticles (PKSAnp)
The PKSAnp's XRD pattern showed that its major diffraction peaks are at 31.44°, 24.6°, 59.9°, 71.2° and 83.7°; corresponding to those
from standard silicon[12] with their inter-planar distances being 3.31A, 4.20A°, 1.89A°, 1.57A°, and 1.37A°. This is in good agreement
with the Joint committee on powder diffraction standard (JCPDS) data belonging to high temperature materials [13] and the phases present
at these peaks being quartz (SiO
2
), and Aluminum Phosphate (AlPO
4
) as shown in fig. 5 and tables 2 and 3 respectively. According to the
XRD study, silica has the greatest proportion of all the compounds present. The wide X-ray diffraction pattern shown that PKSAnp is
amorphous materials. This is consistent with findings in other biomass ash samples[14]. The pick broadening pattern indicates no tacking
faults, microstrain, and other defects in the crystal structure whereas the observed broad hump and the Full Width at Half Maximum,
FWHM suggests that the synthesized materials are nanocrystalline in nature with very small particle size.
Figure 5: XRD pattern of PKSAnp
D. TGA/DTA of the Palm kernel Shell Nanoparticles (PKSAnp)
"Derivatograph OD 102," DTA measurements were logged at a 10
o
C/min argon heating rate. Figure 6 6 shows the findings of the DTA/TGA
scan of the PKSA nanoparticles. The Thermogravimetric analysis (TGA) curve shows a lower proportion of breakdown and a residual
weight stability at temperatures above 1000
o
C, coinciding with the silica content in PKSAnp. After the sample was heated to near 1000
o
C,
the sample began to breakdown with the decomposed byproducts comprising silica. The PKSAnp was found to be more thermally stable
as a result of the silica, which delayed the degrading process. The significant differences in Tm and ∆H indicate stability and structural
conformation. This is comparable and consistent with known high temperature coating materials in previous literature.
Table 2: Peak List
Pos. [°2Th.]
Height [cts]
FWHM Left [°2Th.]
d-spacing [Å]
Rel. Int. [%]
Tip Width
Matched by
24.586840
439.166600
0.102336
4.20421
30.19
0.1228
01-076-0229
31.142640
1454.510000
0.076752
3.33468
100.00
0.0921
01-085-0794
31.349440
1396.110000
0.127920
3.31323
95.98
0.1535
01-076-0229
59.028710
286.298400
0.204672
1.81705
19.68
0.2456
01-085-0794
71.226970
108.047700
0.307008
1.53723
7.43
0.3684
01-085-0794
81.344260
55.742470
0.818688
1.37350
3.83
0.9824
01-085-0794
Position [°2Theta] (Cobalt (Co))
10 20 30 40 50 60 70 80 90
Counts
0
1000
2000
Al P O4
Si O2
Al P O4
Si O2
Si O2
Si O2
PKS650
INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XIII, Issue X, October 2024
www.ijltemas.in Page 97
Table 3: Identified Patterns List
Visible
Ref. Code
Score
Compound Name
Displacement [°2Th.]
Scale
Factor
Chemical
Formula
*
01-085-0794
45
Silicon Oxide
0.000
0.737
SiO
2
*
01-076-0229
33
Aluminum Phosphate
0.000
0.804
AlPO
4
Figure 6: TGA/DTA of the PKSAnp
IV. Conclusion
Palm kernel shell ash nanoparticles were effectively characterized as coating material for high temperature application. The Electron
Dispersion Spectroscope (EDS) result shows that only elements such as C, O, Si, Al, Ca, and K are present in the PKSAnp, with silicon
(Si) found to be dominant. Oxides of Silicon and Aluminum (SiO
2
and Al
2
O
3
) were identified as the key chemical compounds in PKSAnp
from X-Ray Fluorescence (XRF) investigation whereas K
2
O, CaO and Na
2
O were among the other oxides present in traces. The
Thermogravimetric analysis (TGA) curve shows a lower proportion of breakdown and a residual weight stability at temperatures above
1000
o
C. This is comparable and consistent with known high temperature coating materials in previous literature.
References
1. Abhulimen. EA, (2018). “An investigation on the optimal concentration of oil palm (elaeis guineensis) leaves extract as
corrosion inhibitor of carbon steel in deaerated saline solution,” MOJ Applied Bionics and Biomechanics, vol. 2, no. 2, pp.
109–113. doi: 10.15406/mojabb.2018.02.00050.
2. Skawinska A. and Jagustyn, B., (2013). Evaluation of physicochemical properties of palm kernel shell as agro biomass used
in the energy industry.,” CHEMIK, vol. 67, pp. 552–559.
3. Oladosu, K.O., Kareem B., Akinnuli B.O. and Alade A.O. (2016). “Optimization of ash yield from the combustion of palm
kernel shell and selected additives (Al2O3, CaO and MgO) using D-optimal design. Leonardo Electron.,” J. Pract. Technol,
vol. 15, pp. 9–18.
4. Ikumapayi O. M. and Akinlabi E. T., (2018) Composition, Characteristics and Socioeconomic benefits of palm kernel shell
exploitation-an overview. Asian Network for Scientific Information, vol.11, no.5 pp.220–232. doi:
10.3923/JEST.2018.220.232.
5. Howarth G. A. and Manock H. L., (1997). Water-borne polyurethane dispersions and their use in functional coatings,” Surface
Coatings International, vol. 80, no. 7, pp. 324–328 doi: 10.1007/bf02692680.
6. Coating – Retrieved from https://en.wikipedia.org/wiki/Coating, Accessed Sep. 13, 2021.
7. JEOL (2010) TEM Overview of the Metal FUJJI Industry. Access; September 10 2024. Available:
https://www.google.com/search?q=JEOL+(2010)+TEM
8. Electron Nanoscopy Instrumentation Facility.” https://ncmn.unl.edu/enif/about/jeol_2010.shtml. Accessed Apr. 20, 2023.
9. Patterson A. L., (1939). “The Scherrer Formula for X-Ray Particle Size Determination,” Phys. Rev., vol. 56, no. 10, pp. 978–
982. doi: 10.1103/PhysRev.56.978.
10. Experimental Method and Testing Procedures - Laboratory 10: Thermogravimetric Analysis. Accessed Apr. 20, 2023).
https://sites.google.com/a/iastate.edu/laboratory-10-thermogravimetric-analysis/experimental-methods.
11. Marguí E., Queralt I., and E. de Almeida, (2022). X-ray fluorescence spectrometry for environmental analysis: Basic
principles, instrumentation, applications and recent trends,” Chemosphere, vol. 303, p. 135006, Sep., doi:
10.1016/J.CHEMOSPHERE.2022.135006.
INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XIII, Issue X, October 2024
www.ijltemas.in Page 98
12. Patra S., Mitra P., and Pradhan S. K., (2011). Preparation of nanodimensional CdS by chemical dipping technique and their
characterization,” Materials Research, vol. 14, no. 1, pp. 17–20, doi: 10.1590/S1516-14392011005000015.
13. “JCPDS--International Centre for Diffraction Data - LC Linked Data Service: Authorities and Vocabularies | Library of
Congress.” https://id.loc.gov/authorities/names/n78034812.html. Accessed May 16, 2023.
14. Prusty J. K., Patro S. K., and Basarkar S. S., (2016). Concrete using agro-waste as fine aggregate for sustainable built
environment – A review,” International Journal of Sustainable Built Environment, vol. 5, no. 2, pp. 312–333. doi:
10.1016/J.IJSBE.2016.06.003.
