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Influence of Graphene Oxide Nanoparticles on the Mechanical Behavior of Stereolithography Printed Polyether Ether Ketone Composites
(2026-01-01)
Ramkumar, N. P.
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Sharma, S. C.
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Adarsha, H.
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Shaik, Nagoor Basha
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Anurakparadorn, Kanat
The objective of this work is to analyze the impact of graphene oxide percentage on the mechanical behavior of polyether ether ketone (PEEK) nanocomposites produced by stereolithography. The dispersion of graphene oxide (GO) nanoparticles was analyzed using both the scanning electron microscopes and transmission electron microscopes. The mechanical properties of nanocomposites were analyzed by performing hardness and tensile tests in accordance with ASTM standards. The morphology of the final product shows a consistent distribution of GO nanoparticles and a robust interfacial bonding between the nanoparticle reinforcement and the PEEK matrix. It is found that the nanoparticles enhanced the dimensional stability of the nanocomposites, resulting in lower dimensional tolerance compared to the pure PEEK material. The microhardness test has been carried out on the samples, demonstrating the beneficial effect of nanoparticles; the PEEK nanocomposite containing 0.75% nanoparticles gives a higher hardness value of 71 VHN. The strength of nanocomposites was found to increase due to the robust interfacial cohesion between GO and PEEK, resulting in enhanced hardness. Here, the hardness exhibits a negative impact on elongation, which yields a declining trend from (1.7 ± 0.6)% to (1.4 ± 0.6)% with an increase in graphene oxide nanoparticles.
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A Self-Powered and Chemically Responsive Triboelectric Nanogenerator Based on Surface Protonation in SrO2Nanopowder/Graphene Oxide/epoxy Composite for pH Sensing
(2025-12-05)
Saengpoe, Prasert
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Supasai, Wisut
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Amorntep, Narong
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Nilnumpetch, Chatree
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Nokkaew, Manussawee
Practical implementation of triboelectric nanogenerators (TENGs) in autonomous systems is frequently impeded by their inadequate durability in chemically harsh environments. To address this limitation, we present a durable TENG utilizing a strontium dioxide nanopowders/graphene oxide/epoxy resin (SrO<inf>2</inf>NPOs/GO/ER) composite, positioning SrO<inf>2</inf>NPOs as an innovative, high-permittivity filler for triboelectric applications. By synergistically integrating the elevated dielectric constant of SrO<inf>2</inf>NPOs with the interfacial polarization of GO NPOs, our optimized composite achieves an outstanding output of approximately 136 V and 2.3 μA/cm<sup>2</sup>under a 100 N force, exceeding the performance of numerous advanced TENGs. Significantly, we convert a common degradation mechanism, i.e., surface protonation, into a functional sensing approach. The device leverages reversible protonation–deprotonation dynamics to convert environmental pH into distinct electrical signals, enabling self-powered, real-time pH sensing. The sensor exhibits excellent linearity (R<sup>2</sup>> 0.97) across three distinct operational regions (pH 1–12), demonstrating high sensitivity to acidity changes. The device has demonstrated remarkable durability, completing approximately 11,000 mechanical cycles. Also, the proposed device serves high chemical durability, maintaining stable performance (up to 6000 cycles) after 24 h immersion in neutral and alkaline solutions. Our work establishes a resilient, multifunctional platform that simultaneously harvests energy and senses its chemical surroundings by reframing protonation as a design principle. This breakthrough paves the way for next-generation TENGs for use in environmental monitoring, resilient IoT networks, and adaptive self-powered electronics that can function under conditions where the chemical environment changes.
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Speckle imaging of graphene oxide and reduced graphene oxide
(2025-01-01)
Sirikarntayuprakit, Pakkanhan
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Yindeesuk, Witoon
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Buranasiri, Prathan
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Rattanasirawit, Chinnapat
Laser speckle imaging is a non-contact technique for analyzing materials' surface roughness and scattering characteristics. This study investigated the speckle patterns of graphene oxide (GO) in sheet form and reduced graphene oxide (rGO) in powder form under coherent laser illumination. The intensity distributions were recorded using a CMOS camera and analyzed statistically to determine key surface parameters, including speckle contrast and roughness. The results show that GO produces a finer, more uniform speckle pattern with lower contrast and roughness values than rGO, which exhibits coarser and more irregular patterns. These differences reflect the distinct structural characteristics of the two materials. The findings demonstrate the potential of speckle imaging for non-destructive optical characterization of graphene-based materials.
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Hydrogen Sulfide Adsorption on Alumina/Graphene Oxide Composites at Ambient Temperature
(2022-11-01)
Hankoy, Montree
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Kitiwan, Mettaya
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Phrompet, Chaiwat
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Ruttanapun, Chesta
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Kaewpengkrow, Prangtip Rittichote
Hydrogen sulfide (H<inf>2</inf>S) is one of the most common pollutants found in natural gas and industrial waste. Over the few decades, the removal of H<inf>2</inf>S has become a significant problem. In the field of a clean environment such as water purification and toxic gas removal, graphene oxide (GO) has been found to have advantages. In this study, the influence of GO on alumina (Al<inf>2</inf>O<inf>3</inf>) as an adsorbent of H<inf>2</inf>S was examined. A series of Al<inf>2</inf>O<inf>3</inf>/GO (AGO) composites with varying graphene oxide addition (0.5–3.0 wt%) were prepared using the high-temperature sintering method. The X-ray diffraction patterns indicate the primary phase of Al<inf>2</inf>O<inf>3</inf> with hexagonal crystal structure for all AGO composites. Raman spectrometry measurements confirmed that the GO particles were incorporated in AGO composites. The TEM image indicated that GO nanosheets were embedded between Al<inf>2</inf>O<inf>3</inf> grains. The efficiency of AGO adsorbent at ambient temperature was investigated and compared with the pristine Al<inf>2</inf>O<inf>3</inf> adsorbent. The AGO composites adsorbent demonstrated the H<inf>2</inf>S breakthrough capacity in the range of 0.07–0.43 mg/g, which is higher than that of pristine Al<inf>2</inf>O<inf>3</inf> (0.06 mg/g). Furthermore, the highest H<inf>2</inf>S breakthrough capacity of 0.43 mg/g was obtained from AGO containing 3.0 wt% GO. This investigation demonstrates that the AGO adsorbent fabricated using a simple method has the potential to be used for H<inf>2</inf>S removal at ambient temperature.
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Immobilization of Silver Doped Titanium Dioxide onto Stainless Steel Wire Mesh for Photocatalytic Degradation of Gaseous Formaldehyde under Visible Light Irradiation
(2022-03-01)
Sriwong, Chaval
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Klypoo, Akekarat
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Khingram, Aiyakub
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Natluecha, Ratima
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Junyapoon, Suwannee
Titanium dioxide (TiO<inf>2</inf>) photocatalysis can degrade air pollutants into nontoxic substances but it can only be excited by UV light. To eliminate this limitation, silver (Ag) and/or graphene oxide (GO) doped TiO<inf>2</inf> are applied to enhance visible light photocatalytic activity. In this study, Ag-TiO<inf>2</inf> (0. 5%, 1%, 2% w/w), GO/TiO<inf>2</inf> and GO/Ag-TiO<inf>2</inf> were synthesized and then coated on stainless steel mesh. Crystalline and molecule structures, chemical compositions and optical properties of the prepared photocatalyst samples were characterized with X-ray diffraction spectroscopy, X-ray fluorescence spectroscopy, Raman spectroscopy, UV-visible diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, and Scanning electron microscopy equipped with Energy dispersive X-ray spectroscopy techniques. The photocatalytic performances of the various doped catalysts were evaluated according to their abilities to degrade gaseous formaldehyde (HCHO) under visible light. The effect of operational parameters on the photocatalytic degradation of HCHO including layer numbers of photocatalyst, powers of fluorescent lamp and flow rates of HCHO were observed. The results indicated that the presence of Ti, O and Ag elements in Ag-TiO<inf>2</inf> and Ti, O, Ag and C elements in GO/Ag-TiO<inf>2</inf> was confirmed. Proper dispersion of the photocatalyst on the wire mesh was exhibited. Under visible light, the incorporation of Ag and GO in TiO<inf>2</inf> photocatalysts produced higher degradation rates of HCHO than pure TiO<inf>2</inf>. The optimum operating conditions of HCHO degradation at initial concentration of 108.7±1.15 ppm over visible light irradiation for 30 min were 5 layers of 0.5% Ag-TiO<inf>2</inf>, 72 W fluorescent light and 300 ml/ min of HCHO flow rate. Under these conditions, the removal efficiency of gaseous HCHO was 76.70±0.73%.
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Investigation of Contact Angles of SnAgCu Solder Paste Mixed with Graphene Oxide Using Digital Holography Technique
(2021-01-20)
Jongjinakool, Kavisra
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Prakobsang, Tawipon
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Plaipichit, Suwan
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Kanlayasiri, Kannachai
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Kitiwan, Mettaya
Since lead is a pollutant to the environment, therefore lead-free solder paste compounds have been interested in many research teams. The objective of this research is the investigation properties of solder paste with graphene oxide and reduced graphene oxide. In our experimental method the solder pastes of SnAgCu mixed with graphene oxide with bad electrical conductivity at different concentration by weight of 0.00%, 0.05%, 0.1% and 0.2% respectively. Subsequently, the shape changes of the compounds have been investigated by using digital in-line holography using laser diode wavelength 635 nm as the light source. The solder paste compounds were melted at 250 ± 5 °C and were recorded for every 5 seconds. Then, the contact angles of the melted solder paste compound have been determined using their digital holographic reconstructed images.
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Sensing layer combination of vertically aligned ZnO nanorods and graphene oxide for ultrahigh sensitivity IDE capacitive humidity sensor
(2020-06-01)
Pongampai, Satana
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Pengpad, Puttapon
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Meananeatra, Rattanawan
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Chaisriratanakul, Woraphan
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Poyai, Amporn
An interdigitated electrode (IDE) capacitive humidity sensor fabricated on a silicon substrate was used to investigate sensing materials, which proved to be an ultrahigh-sensitivity humidity sensor. A sensing layer combination (SLC) between vertically aligned ZnO nanorods and optimal graphene oxide (GO) was prepared on the device and was tested as a humidity sensor. X-ray diffractometry (XRD) exhibited crystallized wurtzite structure of ZnO nanorods and transmission electron microscope (TEM) shown perfectly indexed hexagonal wurtzite ZnO structure dots position correspondence. A scanning electron microscope (SEM) was used to analyze ZnO nanorods/GO morphologies. Furthermore, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) clearly exhibited GO presence and hydrophilic functional groups (carboxyl, epoxy, and hydroxyl), respectively. The SLC prominently demonstrated ultrahigh sensitivity (up to 196.95% or 1.97 times from commercial sensor; HS1101, Humirel) and linear responses behavior with 0.96 for coefficient of determination. The device sensitivity obviously improved as steps of 40, 50, 60, 70, 80, and 90% RH at values of 1.09, 1.41, 1.51, 1.65, 1.80, and 1.91 times, respectively. The device also exhibited fast response (25 s) and short recovery times (17 s). Its hysteresis (6.58%) manifestly improved to 1.84 times. Moreover, repeatability and long-term ability of the device demonstrated high accuracy (range ±0.37pF) and durability. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
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Study of Nitride Thickness on Sensitivity IDEs Humidity Sensor Based on Graphene Oxide Sensing
(2020-03-01)
Pongampai, Satana
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Pengpad, Puttapon
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Meananeatra, Rattanawan
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Atiwongsangthong, Narin
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Muanghlua, Rangson
An interdigitaged electrodes (IDEs) humidity sensor was patterned like a combs by lithography process based on silicon bulk substrate with different nitride thickness (50, 100 and 150 nm). This research studied an effect of thick nitride on sensitivity of IDEs humidity sensor based APTES adhesive layer with graphene oxide (GO) sensing material. The IDEs humidity sensor based on GO was comparatively examined all thick nitride conditions. Capacitance value of fresh IDEs humidity sensor shown not significant change all nitride thickness but it affected to sensitivity after GO coating due to high GO densified onto IDEs surface. Scanning Electron Microscope (SEM) was analyzed GO distribution and surface morphology. Raman spectroscopy clearly revealed the GO presence. The sensitivity from 50 to 80 %RH for optimal 100 nm thick nitride shows improvement to 2.78 and 1.27 times or 278.35% and 127.46% based on 50 and 150 nm thick nitride, respectively. Furthermore, the optimal condition of IDEs humidity sensor shows a little response and recovery times (11 and 7 sec), low hysteresis (3.21%), fine repeatability as well as high accuracy on long-term ability test. It clearly demonstrated for high sensitivity of nitride IDEs humidity sensor based on GO sensing film deposition.
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Preparation, characterization, and supercapasitive properties of CoO-NiO microflowers incorporated with graphene oxide and reduced graphene oxide hybrid materials
(2018-01-01)
Saei, Worawee
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Buranasiri, Prathan
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Sriwong, Chaval
This research investigated the preparation, characterization and supercapacitive properties of cobalt oxide-nickel oxide (CoO-NiO) microflowers incorporated with graphene oxide (GO) and reduced graphene oxide (RGO) nanosheets. These hybrid materials were easily prepared through a direct mixing of CoO-NiO powder suspended in acidic solution with the appropriate amount of GO and RGO loading to make CoO-NiO/GO and CoO-NiO/RGO hybrid samples, respectively. Then, the obtained hybrid samples were characterized by X-ray powder diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques. The results demonstrated that the crystalline phases and functional groups of all hybrid samples are corresponding to pristine CoO-NiO and RGO. SEM results showed that the CoO-NiO microflowers were impregnated and well-combined with both GO and rGO nanosheets. Moreover, the supercapacitive behavior of pristine CoO-NiO and all hybrid samples were studied using cyclic voltammetry (CV) technique. The results revealed that all hybrid samples exhibited much higher the current density than those of the bare CoO-NiO. Thus, this research indicates that the supercapacitive properties of CoO-NiO incorporated with both GO and RGO hybrid materials are superior to the pure CoO-NiO microflowers.

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