A study on using chitosan as a cleaning agent for used lubricant oil has been successfully conducted. Chitosan, a derivative of chitin derived from abundant crustacean shell waste, has notable properties that make it suitable for applications in various fields, including wastewater treatment, food packaging, wound dressing, biomedical uses, and more. Chitosan is also known to absorb oil, making it an eco-friendly adsorbent for oil spill removal applications. This study aims to explore the extent of chitosan’s eco-friendly application in cleaning used lubricant oil, explicitly focusing on removing permanganate content from used oil. Chitosan solution was added to the used oil, and the treated oil was analyzed using FTIR and UV-Vis. The FTIR spectrum, covering a range of 3500-600 cm⁻¹, indicated the presence of chitosan functional groups in the treated lubricant oil, enhancing its environmental compatibility …

Abstract

Polymers and nanomaterials had been widely applied at electrochemical chemosensor and biosensor. Developing technical energy is still much needed, especially using natural environmental friendly material. Both chitosan of biopolymer and carbon nanodots (CNDs) of nanomaterials are highly studied due to their extraordinary properties. The research focus on chitosan and chitosan/CNDs nanocomposite surface that was applied for electrical energy. Nanocomposite was coated on Cu electrode surface by using electroplating method. The coated electrode was dipped into oil samples. The dipped nanocomposite then was characterized by FTIR, XRD, SEM, and Chemosensor. Nanocomposite structure is still maintain its chemical compound, confirmed by FTIR and XRD, which still maintain amine group; hydroxyl group; and crystalinity of chitosan after CNDs intercoporation. Nanocomposite surface morphology show magnetite particle distribution that spreaded on the surface of electrode for both chitosan and CNDs nanocomposite, which is confirmed by SEM. The free dipping method is based on the sensitive material chitosan/CNDs as a chemosensor; the pressure process on the surface of the chitosan/CNDs sensitive material causes the interaction of metal ions and acid compounds, which involves an iontophoresis process where oil atoms that have been excited in the evaporation process will experience atomic vibrations due to electron transport which then the active groups on the Chemosensor directly absorb and bind metals and acids in oil use a chemisorption process which leads to the transfer of charge from the adsorption particles to the chemosensor surface to fill the holes so that a potential difference occurs in the form of electrical pulses which will then be captured by the Arduino system which will be converted into digital data. This process makes technological energy production in the form of electrical energy faster.

Keywords: Chitosan/CNDs, Material, Electrical Potential, Electrical Energy

1         Introduction

The need for electrical energy is constantly increasing and evolving as an essential part of modern life in various forms. Renewable resource-based materials for electrical applications are investigated not only to emerge as environmentally friendly alternatives but also to find availability, sustainability, and lower cost [1]. Therefore, electrochemical chemosensors and biosensors have great attention used in energy storage technology due to their ability to conduct electricity. However, although much progress has been made in this technology, there are still challenges in terms of improving the sensitivity, specificity and stability of these sensors. For example, the development of chemosensors that are able to detect different types of chemicals with high sensitivity under extreme environmental conditions or biosensors that can function well in various biological matrices are challenges that continue to be faced. One of the materials of interest to researchers is Chitosan [2].

Chitosan is an acetylated chitin-based biopolymer of crustacean shell waste. It is a non-toxic, biodegradable, non- toxic, and environmentally friendly solution that does not cause allergies [3][4]. Commonly, chitosan-based material is excellent in sensing platforms. However, its non-conducting properties need to be combined with conducting nanomaterials. Its –OH and amine (NH2) groups even can be linked or coupled rapidly to various fungtional groups of other biomolecules, which makes this biopolymer able to be combined easily with other materials [5]. By combining with other materials, it is expected to increase the sensitivity properties for energy applications. On the other hand, Carbon nanodots (CNDs) material is a part of nanotechnology currently being developed [6]. CNDs have good solubility, are non-toxic, and have high luminescence so they can be used for

bioimaging, sensors, drug delivery, catalysts, and photovoltaic devices [7]. CNDs can also easily form nanocomposites with other materials due to their abundant functional groups, effectively increasing their multipurpose applications [8]. Chitosan/CNDs nanocomposites can be formed by various methods. The easiest way to make chitosan/CNDs nanocomposites is by electroplating method due to its easy and fast process. In addition, Cu electrodes modified on the surface with chitosan/(CNDs) have electrical potential that can be used for electrical energy [9].

Chitosan/CNDs nanocomposites are being considered as materials for making biosensors because their physicochemical properties can be altered by changing the molecular weight and degree of deacetylation. Chitosan is an abundant polymer in nature and is environmentally friendly because it has a low level of toxicity. In addition, chitosan also has bacterial inhibitory properties, is biodegradable, has high permeability, good gel formation and its surface can be modified using chemical functional groups. These characteristics make chitosan widely applied in various fields, especially medicine and engineering as a biosensor material. Chitosan can be used as a biosensor by modifying its surface using BRE (biological recognition elements). Examples of BRE include DNA, enzymes, proteins, antibodies etc. The type of BRE used in chitosan-based nanocomposites determines the type of signal such as color, intensity, etc. As well as being the main factor in making biosensors. Chitosan is a popular polymer in the biosensor field because it has been successfully used for various kinds of detection [2].

Based on the above background, this research intends to make nanocomposites of Chitosan/CNDs as electrochemical chemosensors and biosensors for electrical energy applications. The easiest way to make chitosan/CNDs nanocomposites is by electroplating method due to its easy and fast process. In addition, Cu electrodes surface modified with chitosan/(CNDs) have electrical potential that can be used as electrical energy components and applications.

2         Materials and Methods

• Materials

Cellulose nanocrystals obtained through synthesis in the Basic Physics USU lab, Indonesia as a precursor to the preparation of Carbon nanodots (CNDs). Ethanol and Destilled water were bought from CV. Rudang Jaya, Indonesia. acetic acid (3% CH₃COOH) were bought from Sigma Alderich in Germany [10].

2.2 Method

• Preparation of Carbon nanodots (CNDs)

Carbon nanodots (CNDs) were made from cellulose nanocrystals using the hydrothermal method. The first step was to mix cellulose nanocrystals with 20 mL of distilled water and 30 mL of ethanol using a magnetic stirrer until homogeneous. The solution was then put into a hydrothermal autoclave and left for four hours at 150°C in the oven. It was then cooled to room temperature. After that, the solution was centrifuged for ten minutes at 10.000 rpm. Subsequently, dialysis was carried out. The solution and solids were stored in sealed containers.

2.2.2 Preparation of Chitosan/CNDs Nanocomposites

Preparation of Chitosan/CNDs Nanocomposites was carried out by one-step method. Dissolve 5 g of chitosan with 15 mL of distilled water and stir with a stirrer at 80 ˚C on a hot plate then add 5 mL of acetic acid (3% CH₃COOH) with a stirring time of 15 minutes (were purchased by Sigma-Aldrich). All the chemical reagents were approved without additional purification. After being homogeneous, CNDs and chitosan that had been mixed with distilled water were put into a beaker glass. It was then heated at 100°C for 1 h in a microwave. The resulting solution will be used as an electrolyte solution in electrode fabrication [11]. The resulting nanocomposite was also oven dried for characterization using FTIR, XRD, and SEM.

2.2.3 Fabrication of Electrodes

In the electrode fabrication section using the electroplating method. Electroplating is a common surface coating process in the manufacturing industry to coat a material (substrate) with another metal. In recent years, this process has undergone many advancements, making it much more accurate and capable of working with a wide variety of materials. The free dipping (electroplating) method based on chitosan/CNDs surface sensitive materials has an electrical potential that can be applied for electrical energy. This method has a positive impact in the field of efficiency on society and industry because it promotes environmental awareness and fuel savings, among others [12]. A total of 10 mL of dissolved chitosan/CNDs was put into a beaker glass to be used as an electrolyte solution in the coating process [13]. Cu electrodes were assembled in parallel and dipped into the chitosan/CNDs solution, then given a voltage of 0.5 Volt for 30 seconds [14]. Then, the sensitive material that has been attached to the electrode surface is dried at 37˚C and tested for chemosensory properties [15][16]. The following is shown in Fig.1. the fabrication process of electrodes.

Fig. 1 Chitosan/CNDs Coating Process

3         Results and Discussions

• Fourier transform infrared (FT-IR)

FTIR spectrophotometry was used to determine the chemical functional group structure of the nanocomposite. Fig. 2 and Fig. 3 demonstrated pure chitosan and chitosan/CNDs nanocomposite in spectrum range of 4000-750 cm^-1. Fig. 2 show 3360 cm^-1; 2919 cm^-1; 1660 cm^-1; and 1592 cm^-1 intensity peaks, which hydroxyl groups; C-O; amide I; and amide II, indicating chitosan characteristics in general [17]. Afterwards, the addition of CNDs into chitosan formed a composite that significantly increased intensity occurred in the hydroxyl region (3430 cm^-1 of Fig. 3), indicating hydrogen bonding between –OH of chitosan and CNDs [18]. In addition to all the functional groups already discussed, there are several other functional groups in the sample, which are identified and characterized in Fig. 2 and Fig. 3. Therefore, the FTIR spectra consolidate the fact that the surface of carbon clusters is passivated by functional groups derived from the heating process and these surface groups are used to crosslink chitosan to make fluorescent nanocomposites [15].

Fig. 2 Fourier transform infrared (FT-IR) spectra of pure chitosan

Fig. 3 Fourier transform infrared (FT-IR) spectra of chitosan-mixed

3.2   X-ray Diffraction (XRD)

Fig. 4 X-rayDiffraction (XRD) spectra of two chitosan pure and chitosan/CNDs

XRD is very useful for studying the crystal structure, chemical composition, and physical properties of nanocomposites. X-ray diffraction study of chitosan and chitosan/CNDs are shown in Fig. 4a and Fig. 4b respectively. The Fig. 4 patern show a high peak at 20° of diffractogram indicated chitosan coating with high degree of crystalinity. Chitosan with intercoporation of CNDs formed composite also show high peak of 20°, indicating the nanocomposites still maintain its crystalnity. The particles show better dispersion stability in the oil after giving chitosan for oil damage compared to other variations as shown by visual stability. The XRD pattern suggested that a single phase of oil has been confirmed. The International Center of Diffraction Data (ICDD), the other peaks that have been identified as pure chitosan are (220), (222), (400), (422), (511), (440) and (533), respectively. As shown in the XRD pattern, the addition of CNDs to chitosan resulted in the same peaks as pure chitosan, with a slight shift of the characteristic peak to a higher angle. This is related to the electrostatic attraction and hydrogen bonds between chitosan chains and doped CNDs, which enhances the energy storage process for electrical energy applications [19].

3.3   Scanning Electron Microscope (SEM)

Sample characterization using SEM tools aims to see the morphology and topography of the sample. EDS is a tool used to determine the elements contained in a sample. EDS can be performed on small areas (dots), lines and squares. An important research tool for improving the efficiency of manufacturing processes. Surface morphology of chitosan/CNDs containing magnetite particles distribution was observed using SEM. Chitosan/CNDs-coated electrode that was dipped in damage oil was observed using SEM as seen in Fig. 5. The image shows cubical particles were spreaded on chitosan and chitosan/CNDs surfaces, which have average size 62.08 nm and 115.67 nm respectively. Already known, cubical structure that sticky on chitosan and modified chitosan surface have average size of 30-110 nm [20]. In particular, it is evidence of the stabilization and relatively even distribution of CDs in the nanocomposite system [21]. Due to the presence of Chitosan, the dispersibility of CNDs is promoted, and a stable chitosan/CNDs nanocomposite is obtained which is favorable for the application process of electric energy [22].

Fig. 5     Scanning Electron Microscope of: (a) Chitosan, (b) Chitosan/CNDs, (c) Magnetite distribution on Chitosan, (d) Magnetite distribution on chitosan/CNDs

Fig. 6 Analysis of Chemosensor sensing sensitivity testing

Fig. 6 shows analysis of Chemosensor sensing sensitivity testing a comparison of frequency with concentration, for the frequency range of 0.2000 Hz, 4000 Hz, 6000 Hz and 8000 Hz and concentrations of 0 ppm, 1 ppm, 1.5 ppm and 2 ppm. In general, chemosensors are defined as “sensory receptors that transduce chemical signals into action potentials”. In particular, if the receptor consists of chemical molecules derived from synthetic route processes, the corresponding sensors based on synthetic receptors are broadly called chemosensors. If the receptor is based on a biological unit, for example natural macromolecules such as peptides, proteins, and nucleic acids, then the appropriate sensor is called a biosensor.Biosensors are chemosensors with biological receptors [23]. Therefore, biosensors are nothing more than a specific type of chemosensor, with bioreceptors [24]. For the frequency of 2000 Hz the concentration is 0.662 ppm, for the frequency 4000 Hz the concentration is 1.224 ppm and for the frequency 6000Hz the concentration is 1.315 ppm. After finding an adequate model for the optimal condition under which Chitosan recognizes CNDs, sensitivity and investigated and validated. The sensitivity of chitosan towards 5 types konsentrasi is investigated under these optimum conditions [25][26].

Fig. 7 Analysis of Chemosensor sensing selectivity testing

Fig. 7 show the analysis of Chemosensor sensing selectivity at 7 frequency variations 0, 200 KHz, 400 KHz, 600 KHz, 800 KHz, 1000 KHz and 1200 KHz for metal level concentrations of 200mg/dl, 300mg/dl, 400mg/dl, 500mg/dl, 600mg/dl,700, The metal level concentration of 200 has a frequency of 1000 Hz in the form of mixed oil, the metal level concentration of 250 the frequency of 1000 Hz is pure oil, the metal level concentration of 400 has a frequency of 1000 Hz in the form of mixed oil [27], while for the metal level concentration of 500 the frequency is 1000 Hz in the form of oil that has been used. Its shows that a significant interaction takes place after Chitosan recognizes in an aqueous medium compared to what happens with the other metal ions [28]. It shows that under this optimal condition, the other metal ions had no significant interactions with the chitosan chemosensor [29]. These results can also be observed with the naked eye by showing that the interaction between chitosan and nanodot also produces significant colour compared to the interactions with the other metal ions. It has red, blue, green, and purple, as seen with the naked eye, while the other interactions occur in colourless solutions. Correspond to the color wheel theory that the chitosan chemosensor interacted with the Nanodot in a selective fashion. The

predicted model of interaction between Chitosan and CNDs and its electronic transitions will be discussed in detail in the theoretical [30].

Fig. 8 Analysis of Chemosensor sensing respon testing

Fig. 8 show the analysis of Chemosensor sensing respon at 8 time variations 0, 200 s, 400 s, 600 s, 800 s, 1000 s

and 1200 s and 1400 s for metal level concentrations of 100 mg/dL, 150 mg/dL, 200 mg/dL, 250 mg/dL, 300mg/dL, 350 mg/dL. the highest point in 200 s, 600 s and 1000 s with red mixed oil, blue pure oil and purple damage oil. The following table 1 shows a comparison of materials using the electroplating method

Table 1. the result of material synthesis using the electroplating method.

4         Conclusion

Chitosan/CNDs coated Cu electrode had been done by using electroplating method. Nanocomposite structure is still maintain its chemical compound and adsorp metalite particles on it’s surface. The free dipping method based on the sensitive material chitosan/CNDs as a chemosensor the pressure process on the surface of the chitosan/CNDs sensitive material which causes the interaction of metal ions and acid compounds which involves an ionthophoresis process where oil atoms that have been excited in the evaporation process will experience atomic vibrations due to electron transport which then the active groups on the Chemosensor directly absorb and bind metals and acids in oil use a chemisorption process which leads to the transfer of charge from the adsorption particles to the chemosensor surface to fill the holes so that a potential difference occurs in the form of electrical pulses which will then be captured by the Arduino system which will be converted into digital data. This process makes technological energy production in the form of electrical energy faster.

5         Credit authorship contribution statement

Muhammadin Hamid: Software,Writing – original draft. Indri Dayana: Conceptualization, Methodology, Writing

– original draft. Habib Satria: Data curation. Muhammad Fadlan Siregar, Martha Rianna, Hadi Wijoyo:

Writing – review & editing.

6

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

7  Acknowledgments

The author would like to thank the Universitas Sumatera Utara and Medan Area University for supporting this research.

References

• Al-Najjar, C. Pfeifer, R. Al Afif, H.J. El-Khozondar, Estimated view of renewable resources as a sustainable electrical energy source, case study, Designs 4 (2020) 1–18. https://doi.org/10.3390/designs4030032.
• Petrucci, M. Pasquali, F.A. Scaramuzzo, A. Curulli, Recent advances in electrochemical chitosan-based chemosensors and biosensors: Applications in food safety, Chemosensors 9 (2021) 1–30. https://doi.org/10.3390/chemosensors9090254.
• S. Malik, R.A. Alsantali, A.Y.A. Alzahrani, Q.M.S. Jamal, E.M. Hussein, K.A. Alfaidi, M.M. Al-Rooqi,

R.J. Obaid, M.A. Alsharif, S.F. Adil, R.S. Jassas, Z. Moussa, S.A. Ahmed, Multicomponent synthesis, cytotoxicity, and computational studies of novel imidazopyridazine-based N-phenylbenzamides, J. Saudi Chem. Soc. 26 (2022) 101449. https://doi.org/10.1016/j.jscs.2022.101449.

• M. Al-Rooqi, M.M. Hassan, Z. Moussa, R.J. Obaid, N.H. Suman, M.H. Wagner, S.S.A. Natto, S.A. Ahmed, Advancement of chitin and chitosan as promising biomaterials, J. Saudi Chem. Soc. 26 (2022) 101561. https://doi.org/10.1016/j.jscs.2022.101561.
• N.V. Ravi Kumar, Chitin and chitosan fibres: A review, Bull. Mater. Sci. 22 (1999) 905–915. https://doi.org/10.1007/BF02745552.
• U. Mughal, J. Ashraf, E.M. Hussein, Y. Nazir, A.S. Alwuthaynani, N. Naeem, A. Sadiq, R.I. Alsantali,

S.A. Ahmed, Design, Synthesis, and Structural Characterization of Thioflavones and Thioflavonols as Potential Tyrosinase Inhibitors: In Vitro and In Silico Studies, ACS Omega 7 (2022) 7444–17461. https://doi.org/10.1021/ACSOMEGA.2C01841.

• I.I. Alsantali, E.U.U. Mughal, N. Naeem, M.A.A. Alsharif, A. Sadiq, A. Ali, R.S. Jassas, Q. Javed, A. Javid, S.H. Sumrra, A.A.A. Alsimaree, M.N.N. Zafar, B.H.H. Asghar, H.M.M. Altass, Z. Moussa, S.A.A. Ahmed, Flavone-based hydrazones as new tyrosinase inhibitors: Synthetic imines with emerging biological potential, SAR, molecular docking and drug-likeness studies, J. Mol. Struct. 1251 (2022). https://doi.org/10.1016/j.molstruc.2021.131933.
• Zulfajri, S. Sudewi, S. Ismulyati, A. Rasool, M. Adlim, G.G. Huang, Carbon dot/polymer composites with various precursors and their sensing applications: A review, Coatings 11 (2021). https://doi.org/10.3390/coatings11091100.
• Arrasyid, I. Dayana, H. Satria, M. Mungkin, Development of Chitosan and NanoDot (CNDs) as chemosensors for contact oil damage detection at magnetic fields on electric currents in solar cells, J. Ilm. Tek. Inform. Elektro 2 (2023) 81–84. https://doi.org/10.31289/jitek.v2i2.2893.
• Humaidi, M. Hamid, H. Wijoyo, Study and characterization of BaFe12O19/PVDF composites as electrode materials for supercapacitors, Biosens. Bioelectron. X 19 (2024) 100507. https://doi.org/10.1016/j.biosx.2024.100507.
• Singh, K. Shitiz, A. Singh, Chitin and chitosan: biopolymers for wound management, Int. Wound J. 14 (2017) 1276–1289. https://doi.org/10.1111/iwj.12797.
• Hamid, M., Humaidi, S., Saragi, I. R., Simanjuntak, C., Isnaeni, I., Wijoyo, The Effectiveness Of Activated Carbon From Nutmeg Shell In Reducing Ammonia (NH3) Levels In Fish Pond Water, Carbon Trends 14 (2024) 1–12.
• A. Agnihotri, N.N. Mallikarjuna, T.M. Aminabhavi, Recent advances on chitosan-based micro- and nanoparticles in drug delivery, J. Control. Release 100 (2004) 5–28. https://doi.org/10.1016/j.jconrel.2004.08.010.
• Hamid, M. Rianna, M.D.E. Vania, I.D. Yanti, F.A.A. Manurung, R. Afriandani, A. Daulay, Sweet

potato‑derived carbon nanosheets incorporate NiCo2O4 nanocomposite as electrode materials for supercapacitors, Mater. Sci. Energy Technol. 6 (2023) 382–387. https://doi.org/10.1016/j.mset.2023.03.006.

• Robertson, Chitin and Chitosan: Production and Application of Versatile Biomedical Nanomaterials, Am. Math. Mon. 111 (2004) 915. https://doi.org/10.2307/4145104.
• Hamid, Susilawati, S.A. Amaturrahim, I.B. Dalimunthe, A. Daulay, Synthesis of magnetic activated carbon-supported cobalt(II) chloride derived from pecan shell (Aleurites moluccana) with co-precipitation method as the electrode in supercapacitors, Mater. Sci. Energy Technol. 6 (2023) 429–436. https://doi.org/10.1016/j.mset.2023.04.004.
• Kolhe, R.M. Kannan, Improvement in ductility of chitosan through blending and copolymerization with PEG: FTIR investigation of molecular interactions, Biomacromolecules 4 (2003) 173–180. https://doi.org/10.1021/bm025689+.
• Konwar, N. Gogoi, G. Majumdar, D. Chowdhury, Green chitosan-carbon dots nanocomposite hydrogel film with superior properties, Carbohydr. Polym. 115 (2015) 238–245. https://doi.org/10.1016/j.carbpol.2014.08.021.
• Amari, N. Elboughdiri, D. Ghernaout, R.H. Lajimi, A.M. Alshahrani, M.A. Tahoon, F. Ben Rebah, Multifunctional crosslinked chitosan/nitrogen-doped graphene quantum dot for wastewater treatment, Ain Shams Eng. J. 12 (2021) 4007–4014. https://doi.org/10.1016/j.asej.2021.02.024.
• Hamid, T.I. Nasution, R. Elfinita, H. Wijoyo, I. Isnaeni, Reducing Ammonia (NH3) Levels in Fish Cage Water Using Activated Carbon Adsorbent Derived from Purple Corn Cob, Sci. Technol. Indones. 9 (2024) 669–681. https://doi.org/10.26554/sti.2024.9.3.669-681.
• Mohammadi, S. Mohammadi, A. Salimi, A 3D hydrogel based on chitosan and carbon dots for sensitive fluorescence detection of microRNA-21 in breast cancer cells, Talanta 224 (2021) 121895. https://doi.org/10.1016/j.talanta.2020.121895.
• Yan, X. Yang, Y. Hua, Z. Li, Y. Liu, Y. Lin, An impedance sensor based on chitosan-carbon quantum dots for the detection sialic acid in humuan serum, Microchem. J. 169 (2021) 106520. https://doi.org/10.1016/j.microc.2021.106520.
• Hamid, M. Rianna, W.R. Rangkuti, T. Sembiring, P. Sebayang, Study and characterization rGO/Fe3O4 in microstructure and – magnetic properties, South African J. Chem. Eng. 42 (2022) 280–282. https://doi.org/10.1016/j.sajce.2022.08.008.
• Espina-Casado, A. Fernández-González, M.E. Díaz-García, R. Badía-Laíño, Smart carbon dots as chemosensor for control of water contamination in organic media, Sensors Actuators, B Chem. 329 (2021). https://doi.org/10.1016/j.snb.2020.129262.
• Brigham, Chitin and Chitosan: Sustainable, Medically Relevant Biomaterials, Int. J. Biotechnol. Wellness Ind. 6 (2017) 41–47. https://doi.org/10.6000/1927-3037.2017.06.02.1.
• Zargar, M. Asghari, A. Dashti, A Review on Chitin and Chitosan Polymers: Structure, Chemistry, Solubility, Derivatives, and Applications, ChemBioEng Rev. 2 (2015) 204–226. https://doi.org/10.1002/cben.201400025.
• Ashraf, E.U. Mughal, R.I. Alsantali, R.J. Obaid, A. Sadiq, N. Naeem, A. Ali, A. Massadaq, Q. Javed, A. Javid, S.H. Sumrra, M.N. Zafar, S.A. Ahmed, Structure-based designing and synthesis of 2- phenylchromone derivatives as potent tyrosinase inhibitors: In vitro and in silico studies, Bioorganic Med. Chem. 35 (2021) 116057. https://doi.org/10.1016/j.bmc.2021.116057.
• C.A. Wan, B.C.U. Tai, CHITIN – A promising biomaterial for tissue engineering and stem cell technologies, Biotechnol. Adv. 31 (2013) 1776–1785. https://doi.org/10.1016/j.biotechadv.2013.09.007.
• Manalu, K. Tarigan, S. Humaidi, M. Ginting, K. Sebayang, M. Rianna, M. Hamid, A. Subhan, P. Sebayang, I.P. Manalu, Synthesis, Microstructure and Electrical Properties of NiCo2O4/rGO Composites as Pseudocapacitive Electrode for Supercapacitors, Int. J. Electrochem. Sci. 17 (2022) 22036. https://doi.org/10.20964/2022.03.11.
• Shaya, P.R. Corridon, B. Al-Omari, A. Aoudi, A. Shunnar, M.I.H. Mohideen, A. Qurashi, B.Y. Michel,

100529. Burger, Design, photophysical properties, and applications of fluorene-based fluorophores in two-photon fluorescence bioimaging: A review, J. Photochem. Photobiol. C Photochem. Rev. 52 (2022) 100529. https://doi.org/10.1016/j.jphotochemrev.2022.100529.

• Sajjadnejad, N. Setoudeh, A. Mozafari, A. Isazadeh, H. Omidvar, Alkaline Electrodeposition of Ni–ZnO Nanocomposite Coatings: Effects of Pulse Electroplating Parameters, Trans. Indian Inst. Met. 70 (2017) 1533–1541. https://doi.org/10.1007/s12666-016-0950-4.
• Beltowska-Lehman, A. Bigos, P. Indyka, A. Chojnacka, A. Drewienkiewicz, S. Zimowski, M. Kot, M.J. Szczerba, Optimisation of the electrodeposition process of Ni-W/ZrO2 nanocomposites, J. Electroanal. Chem. 813 (2018) 39–51. https://doi.org/10.1016/j.jelechem.2018.02.013.
• Singh, A.S. Dhaliwal, Electrochemical and photocatalytic degradation of methylene blue by using rGO/AgNWs nanocomposite synthesized by electroplating on stainless steel, J. Phys. Chem. Solids 160 (2022) 110358. https://doi.org/10.1016/j.jpcs.2021.110358.
• Verma, C. Balomajumder, Synthesis of magnetic nickel ferrites nanocomposites: An advanced remediation of electroplating wastewater, J. Taiwan Inst. Chem. Eng. 112 (2020) 106–115. https://doi.org/10.1016/j.jtice.2020.07.006.

Potatoes are one of everyone favorite foods.
Some regions use potatoes as their staple food.
This is because potatoes contain many
beneficial elements, such as potassium [1-2]
It turns out that potassium can also be used for
batteries. In general, Lithium is the element
most often used to make batteries. Almost all
electronics, such as laptops, smartphones, etc.
use this battery. However, lithium has several
disadvantages such as being expensive, less
safe, and not long-lasting[3-4]. Scientists in
many fields are working around the clock to
improve and replace lithium-ion battery
technology. In this case, the researchers looked
for a special type of pure battery, a metal
battery that maintains the rechargeability and
longer service life of a lithium compound and
graphite anode. They found that potassium had
potential, but after testing it turned out it was
not as good as expected [5-7]
A battery is something that causes chemical
energy to be converted into electricity. The
battery has a positive side (terminal) and a
negative side (terminal). The downside is that it
is a source of electrons that energize the cables
connected to the electronic devices. Batteries

power electronic devices when connected to
conductive materials, such as wires.
Potato batteries are a type of electrochemical
battery, or cell. Certain metals (zinc in the
example below) undergo a chemical reaction
with the acid in the potato. This chemical
reaction produces electrical energy that can
power devices [8-10]
Typically, the dendrites grow and have sharp
edges that penetrate vital and volatile parts of
the battery, causing chemical leaks or risk of
fire. Lithium atoms have low surface mobility,
which means that the atoms that combine to
form dendrites end up piling up on each other,
like droplets forming large icicles on the corner
of a house roof[11-12].
In contrast to Lithium, Potassium has a higher
surface mobility, meaning the atoms stack up,
but then spread out on their own. The image is
like sand poured in a wide circle. This is quite
beneficial because it can reduce the risk of
explosion [13].
The mechanism of the battery is controlled by
the heat from the battery itself. According to
researchers, the heat from the battery is enough
to disperse the atoms over the surface and the
system will not melt the potassium or damage
the battery as a whole[14-15].
The discovery of a battery that can self-
recovery is not the first. But seeing that
potassium is cheap and easy to obtain is
something that will be profitable for the battery
industry in the future [16].
That is why it is necessary to This research
discusses alternative potato sheets that can
replace lithium for future batteries, with a
sample of 20 potato experiments.

Apa itu Pengukuran?

Pengukuran merupakan membandingkan satu besaran dengan besaran lainnya dengan menggunakan alat ukur.

Besaran merupakan segala sesuatu yang dapat diukur dinyatakan dengan angka dan mempunyai satuan.

Besaran secara umum terbagi dua yaitu, besaran pokok dan besaran turunan

Sedangkan yang termasuk kedalam besaran listrik berupa kuat arus listrik, tegangan listrik, kapasitansi, konduktivitas dan lain sebagainya.

Fisika dan matematika yang merupakan mata kuliah umum dan dasar di teknik berbasic logika dan penalaran. Untuk dapat menguasai fisika dan matematika hanya perlu banyak berlatih soal-soal, paham materi dan berpikiran logika.

Pemahaman yang baik dalam mata kuliah fisika dan matematika dalam mengembangkan pola pikir yang kritis mahasiswa. Pemikiran kritis ini sangat baik untuk lebih mengembangkan potensi yang ada didalam dirinya sendiri dan lingkungannya.

Tips mengerjakan soal pertidaksamaan linier 2 dan 3 variabel yang aplikasinya di rangkain listrik

1. setiap variabel yang ingin dicari terlebih dahulu yang lain variabel anggap nol
2. selesaikan satu persatu hingga dapat variabel yang diinginkan
3. Misalnya selesaikan dulu variabel x baru y untuk 2 variabel, jika 3 variabel lanjtkan variabel z, ingat saat mencari satu variabel variabel yang lain nol kan
4. masukkan variabel yang telah didapatkan lalu buat grafiknya

1.langkah awal kerjakan soal integral tersebut seperti biasa mengerjakan soal integral biasa

2. Jika berbatas siap diselesaikan integral masukkan batas bawah dan atas

3. Lalu kurangi keduanya batas

4. Hasil pengurangan anggap x

5. Masukkan x ke persamaan integral trigonometri selesaikan hasil integral trigonometri

6. Lalu gambarkan grafiknya

Reaktansi induktif dan reaktansi kapasitif sebenarnya sama-sama mencari hambatan untuk induktif dan kapasitif. Yang hambatan secara keseluruhan dinamakan impedansi

Z=√R2+(XL-XC)2

Reaktansi induktif XL= w. L

Reaktansi kapasitif XC= 1/w.C

Dimana w=2nf

Perbedaan arus AC dan DC

Arus AC merupakan jenis arus listrik yang nilainya berubah terhadap satuan waktu atau cenderung tidak stabil. Sedangkan arus DC ialah arus listrik yang nilainya tetap terhadap satuan waktu, sehingga lebih stabil pada penggunaanya.

Alasan listrik AC lebih banyak digunakan dibanding DC

Karena penggunaan umumnya oleh rumah tangga, listrik AC diketahui lebih ekonomis dibandingkan DC. Selain itu, arus yang dapat dihasilkan oleh arus bolak-balik jauh lebih besar dan dapat menghantar arus dengan jarak yang lebih jauh. Listrik AC juga memiliki sistem yang lebih aman.