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61	Organics Chemistry	ABS-96
Development of Sacha Inchi (Plukenetia Volubilis L.) Seed Extract in Lip Balm Preparations Istnaini Yuli Fitriani Chemistry Education, Sebelas Maret University Jalan Ir. Sutami No.36, Surakarta 57126, Indonesia Abstract Excessive exposure to ultraviolet (UV) light can cause damage to the lips, such as dryness, chapping, and hyperpigmentation. Using a lip balm containing natural active ingredients is one effective protective measure. Sacha Inchi seeds (Plukenetia volubilis L.) are known to be rich in essential fatty acids and antioxidant compounds, which have the potential to be active ingredients in sunscreen lip balms. This study aimed to explore Sacha Inchi seed extract obtained through three extraction methods: maceration, soxhletation, and direct pressing, and to evaluate the characteristics of the resulting lip balms. Sacha Inchi seed extract was obtained using maceration with ethanol as a solvent, soxhletation, and direct pressing without a solvent. The extraction results were then compared to determine the best method based on yield. The best extract was formulated into lip balms with three concentration variations (F1, F2, F3) and one base without extract as a control. The results showed that the soxhletation method produced extracts with optimal yields and antioxidant activity compared to maceration and direct pressing. The resulting lip balms had good organoleptic characteristics, including a homogeneous texture, attractive color, and an acceptable aroma. The SPF values &#8203-&#8203-indicated that all formulations had moderate to high UV protection. Antioxidant activity showed that formulations with higher extract concentrations had lower IC50 values, indicating stronger antioxidant activity than the base. Based on these results, Sacha Inchi seed extract obtained through the soxhletation method has the potential to be developed as an active ingredient in lip balms with good antioxidant activity and UV protection. Keywords: sacha inchi, lip balm, antioxidant, SPF Share Link | Plain Format | Corresponding Author (Istnaini Yuli Fitriani)

62	Organics Chemistry	ABS-99
Exploration of Anthocyanins from Parijoto Fruits (Medinilla speciosa) as A Sustainable Colorant with Promising Biological Activities Muhammad Hizbul Wathon,1,* Firda Alfa Nikmaturrohmah,1 Widiastuti Agustina Eko Setyowati,1 Elfi Susanti VH,1 Hiyas A. Junio2 1Chemistry Education Study Program, Faculty of Teacher Training and Education, Universitas Sebelas Maret, Surakarta, Indonesia 2Institute of Chemistry, University of the Philippines Diliman, Philippines *corresponding author^s e-mail: m.h.wathon[at]staff.uns.ac.id Abstract Anthocyanins are highly coloured (red, purple, blue), water-soluble, and non-toxic compounds which can be found easily in plants, especially fruits, vegetables, flowers, and tubers. Besides the interesting colour displayed by anthocyanins, these compounds have also been reported to show various health benefits. This study was conducted to explore the anthocyanins from Parijoto fruits (Medinilla speciosa) and assess their potential biological activities. Anthocyanins from Parijoto fruits were extracted with acidified water (0.1% v/v HCl) followed by purification using an Amberlite XAD-7 packed SPE column with a sequential solvent system with different polarities (acidified water 0.1% v/v HCl, ethyl acetate, and acidified ethanol 0.1% v/v HCl). The dried post-SPE ethanolic extract was characterised using a UV-Vis spectrophotometer, FTIR, and LC-HRMS. TPC, TFC, and TMAC were determined. Colour stability of anthocyanins were studied at pH 1-12 during storage for 1 week. Additionally, brown Index (BI) and violet index (VI) were determined. Antioxidant and anticancer activities of anthocyanins were also studied. Keywords: Anthocyanins, Parijoto fruits (Medinilla speciosa), sustainable colorant, Antioxidant, Anticancer Share Link | Plain Format | Corresponding Author (Muhammad Hizbul Wathon)

63	Organics Chemistry	ABS-101
Optimization of Formulation and Characterization of Cassia Cinnamon (Cinnamomum cassia) Essential Oil Submicroencapsulation to Enhance Antioxidant and Antibacterial Activities Sri Retno Dwi Ariani1*, Ani Dwi Ratnasari1, Nadia Indri Safitri1, Endang Susilowati1, Muhammad Hizbul Wathon1, dan Ifah Munifah2 1Chemistry Education Study Program, Faculty of Teacher Training and Education, Universitas Sebelas Maret, Surakarta, Central Java 57126, Indonesia 2Research Center for Applied Microbiology, National Research and Innovation Agency (BRIN), Cibinong, West Java 16911, Indonesia Abstract The purpose of this study was to identify the chemical components of cassia cinnamon (Cinnamomum cassia) essential oil, determine the best formulation of cassia cinnamon essential oil submicroencapsulation based on antioxidant and antibacterial activities, and characterize the best cassia cinnamon essential oil submicroencapsulation. The research methods included the extraction of cassia cinnamon essential oil using the steam-water distillation method, identification of chemical components using GC-MS, preparation of cassia cinnamon essential oil submicroencapsulation with variations in essential oil concentration using the emulsification method combined with freeze-drying, determination of the best cassia cinnamon essential oil submicroencapsulation based on antioxidant and antibacterial activities, and characterization of the best cassia cinnamon essential oil submicroencapsulation. Based on the research results, cassia cinnamon essential oil was found to contain nine compounds, with cinnamaldehyde (94.69%) as the main component. The best submicroencapsulation of cassia cinnamon essential oil was obtained at an essential oil concentration of 15%, with IC50 values of 22.81 ppm for DPPH, 17.36 ppm for ABTS, and 13.14 ppm for FRAP, and inhibition zones of 18.45 mm against Escherichia coli ATCC 25922 and 25.56 mm against Staphylococcus aureus ATCC 25923, with characterization results showing an encapsulation efficiency of 84%, a particle size of 846.2 nm (submicro category), compact and stable particle morphology based on SEM, and encapsulated active functional groups confirmed through FTIR. Keywords: antibacterial, antioxidant, Cinnamomum cassia essential oil, submicroencapsulation Share Link | Plain Format | Corresponding Author (Sri Retno Dwi Ariani)

64	Organics Chemistry	ABS-102
Effectiveness of Ultrasound-Assisted Synthesis of 4-ethyl-4-chloro Chalcone and Its Antibacterial Activity Elfi Susanti VH, Sri Mulyani, Sri Retno Dwi Ariani, Suryadi Budi Utomo, Muhammad Hizbul Wathon, Widiastuti Agustina Eko Setyowati, Annisa Zahronita Utami Universitas Sebelas Maret Abstract This study aimed to synthesize and evaluate the antibacterial activity of 4-ethyl-4-chloro chalcone using ultrasonic irradiation as an environmentally friendly and energy-efficient approach. The Claisen-Schmidt condensation reaction was carried out between 4-ethylacetophenone and 4-chlorobenzaldehyde in ethanol with NaOH as a base catalyst at room temperature. The reaction results showed an increase in synthesis efficiency compared to conventional methods, with a shorter reaction time and higher yield. The structure of the synthesized compound was confirmed by FTIR, H, and C NMR spectroscopy, which revealed the presence of &#945-,&#946--unsaturated carbonyl groups characteristic of chalcones. Antibacterial activity was conducted against Escherichia coli (a Gram-negative bacterium) and Staphylococcus aureus (a Gram-positive bacterium) using the disc diffusion method. The test results showed that 4-ethyl-4-chloro chalcone produced an inhibition zone of 15.5 mm against E. coli and 11.4 mm against S. aureus. This value indicates that the compound is more active against E. coli than S. aureus, possibly due to the highly lipophilic nature of the ethyl (-C&#8322-H&#8325-) and chloro (-Cl) groups, which increases its ability to penetrate the bacterial lipid membrane. Based on the results of this study, the ultrasonic-assisted synthesis method has been proven effective in producing chalcone compounds with potential antibacterial activity, supporting the application of the sonochemical approach in the synthesis of environmentally friendly bioactive compounds. Keywords: Chalcone- ultrasonic- antibacteria- Escherichia coli- Staphylococcus aureus Share Link | Plain Format | Corresponding Author (Elfi Susanti VH)

65	Physical Chemistry	ABS-13
BIVO4-DECORATED ON bcl SILICA USING IMPREGNATION METHOD FOR PHOTOCHEMICAL APPLICATIONS Kamil Ahmad**, Sudirman, Irma Mulyani, Veinardi Suendo* Bandung Institute of Technology, Bandung, Indonesia Abstract Now a days, demand for clean energy has driven research into efficient solar energy utilization. Therefore, this study proposes the synthesis of a unique material by decorating bismuth vanadate (BiVO&#8324-) on bicontinuous concentric lamellar (bcl) silica. bcl Silica as support material has a unique spherical porous morphology, a large surface area, thermodynamic stability, an open channel structure, etc., while, on the other hand, BiVO&#8324- is a cost-effective, non-toxic semiconductor with a narrow bandgap (2.3-2.4 eV). Despite recent advancements, Bismuth vanadate (BiVO&#8324-) faces challenges, including rapid electron-hole pair recombination and limited visible-light absorption, which hinder its broader applications. This study aims to address these limitations of BiVO4 by decorating BiVO&#8324- on support catalyst material, bcl silica. The unique structural features of bcl silica, such as large surface area, adjustable pore size, and high thermal stability, are expected to enhance visible-light absorption and charge recombination properties of BiVO4, thereby synergistically increasing photocatalytic performance and yielding a more efficient photocatalyst. In this study, bcl silica was synthesized using the reflux method, while BiVO4 was synthesized by the hydrothermal method. After successful synthesis of both materials, The next step was to decorate synthesized bcl silica using impregnation method. From SEM bcl silica particle size was between 550-650 nm, It was found that the BET surface area was up to 782 m2/g, while the pore volume and pore size was up to 1.12 cm3/g and 5.1 nm, respectively. The resulting material was characterized by photoluminescence (PL) and UV-Vis spectroscopy. Raman spectroscopy, SEM, XRD, and DRS. Preliminary DRS results indicate a narrow bandgap, while Raman analysis confirms molecular vibrations. XRD provides information on the crystal structure and phase composition of BiVO4 synthesized- SEM shows that the bcl morphology of bcl silica was preserved. Keywords: bicontinuous concentric lamellar (bcl) silica, bismuth vanadate, impregnation, photochemical applications. Share Link | Plain Format | Corresponding Author (Kamil Ahmad)

66	Physical Chemistry	ABS-16
Synthesis of Silver-Alginate Nanocomposites Using CaCl2 Gelling Agent for Antibacterial Gel Application Endang Susilowati, Sulistyo Saputro, Lina Mahardiani, Nanik Dwi Nurhayati, Budi Hastuti, Wirawan Ciptonugroho, Muhammad Iqbal Juniardi Department of Chemistry Education, Faculty of Teacher Training and Education, Universitas Sebelas Maret, Surakarta, Indonesia Abstract Silver nanoparticles are known to have a broad antibacterial spectrum, but their stability and potential toxicity need to be controlled through a biocompatible matrix system. Alginate as an anionic biopolymer has the ability to form gels through ionic cross-linking with CaCl&#8322-, thus potentially becoming a stable silver nanoparticle carrier matrix while improving the physical properties of the gel for topical applications. This research was conducted in 2 stages. The first stage, namely the synthesis of silver-alginate (Ag/Alg) nanocomposite colloids with the help of microwave irradiation, with AgNO3 as a precursor agent, alginate as a reducing agent and stabilizer, and NaOH as an accelerator. The second stage, namely the preparation of Ag/Alg nanocomposite gel preparations with CaCl2 cross-linking (Ag/Alg-CaCl2). The formation of silver nanoparticles was identified by a UV-Vis spectrophotometer based on the localized surface plasmon resonance (LSPR) phenomenon. Furthermore, the formed Ag/Alg-CaCl2 nanocomposite gel was subjected to organoleptic tests, spreadability, adhesiveness, viscosity, pH, functional groups, morphology and antibacterial activity tests against S.aureus and E.coli bacteria. The results showed that silver nanoparticles were identified by the appearance of LSPR absorption bands at 408.5-412.4 nm. The greater the concentration of AgNO3, the more silver nanoparticles were produced. The addition of CaCl2 increased the spreadability, adhesiveness, and viscosity of the Ag/Alg-CaCl2 nanocomposite gel preparation. The functional groups of the Ag/Alg-CaCl2 nanocomposite gel preparation in the FTIR spectrum were influenced by the electrostatic interaction between CaCl2 and Alginate. Alginate has a smooth and homogeneous morphological structure, while the Alg-CaCl2 and Ag/Alg-CaCl2 gel preparations showed a hollow morphological structure. The higher the concentration of AgNP, the higher the antibacterial activity of the Ag/Alg-CaCl2 nanocomposite gel. Keywords: nanocomposite, Silver nanoparticles, Alginate, CaCl2, gel, AntibacterialPlease Just Try to Submit This Sample Abstract Share Link | Plain Format | Corresponding Author (Endang Susilowati)

67	Physical Chemistry	ABS-17
Optimization of an Electrochemical Biosensor Based on Baciillus megaterium Biofilm for Hexavalent Chromium Detection Novik Nurhidayat*, Khalid Nurhidayat** and Zubaedah Ningsih*** *Research Center for Applied Miicrobiology BRIN. ** Departement Chemistry, IPB University *** Departement Chemistry, Brawijaya University Abstract Hexavalent chromium (CrVI) is a toxic anthropogenically industrial material. This study developed and optimized a bacterial based biosensor for the soluble CrVI. The Bacillus megaterium producing chromium reductase was immobilized onto screen printed carbon electrode (SPCE) to electrochemically detect the CrVI in the solution. The experimental analysis indicated that bacterial density, electrolyte solution pH, and scan rate significantly affected the biosensor current (p < 0.05). Optimization revealed that the biosensor works best at bacterial density of log phase, pH 3, and a scan rate of 100 mVs-1 with a desirability of 0.923602, resulting in a cathodic peak current of -61.16 &#956-A. Keywords: SPCE Biosensor, Bacillus megaterium, hexavalent chromium, cyclic voltammetry Share Link | Plain Format | Corresponding Author (Novik Nurhidayat)

68	Physical Chemistry	ABS-28
Optical Properties and Photodynamic Inactivation of Candida albicans Biofilm Using Green-Synthesized Silver Nanoparticles Pryandi M. Tabaika1, Ulya Farahdina1, Rini Khamimatul Ula2, Nurul Jadid3, Sri Dewi Astuty4, Nasori Nasori1 1Department of Physics, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia 2Research Center for Physics, Indonesia Institute of Sciences, Building 440, PUSPIPTEK South Tangerang, Indonesia 3Department of Biology, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia 4Department of Physics, Hasanuddin University, Surabaya 60111, Indonesia Abstract Biofilms formed by Candida albicans exhibit high resistance to conventional antifungal therapy. This study aims to evaluate the optical characteristics and photodynamic inactivation (PDI) activity of silver nanoparticles (AgNPs) synthesized using Pogostemon cablin leaf extract. Optical characterization was performed using UV-Vis spectroscopy and bandgap energy analysis. The UV-Vis spectrum showed a maximum absorption peak at 442 nm, while the estimated bandgap energy was 2.31 eV. The photodynamic activity was evaluated against Candida albicans biofilm under blue LED irradiation, and biofilm metabolic activity was quantified using the XTT reduction assay. The results demonstrated that the combination of AgNPs and blue LED irradiation produced a significant inhibition of biofilm viability compared with the control groups. These findings indicate that AgNPs synthesized from Pogostemon cablin leaf extract possess suitable optical properties and have potential as photosensitizers for photodynamic therapy against Candida albicans biofilms. Keywords: Photodynamic Inactivation, Candida Albicans biofilm, Silver Nanoparticles, Green synthesized Share Link | Plain Format | Corresponding Author (Nasori Nasori)

69	Physical Chemistry	ABS-34
Comparative Investigation of Atmospheric, Vacuum, and Reactive Distillation for Enhanced Separation Efficiency of Lactic Acid and Formic Acid from Glycerol Conversion Mixtures Enggal Nurisman (a), Susila Arita (a*), Leily Nurul Komariah (a), Putra Rajasa (a), and Dina Aprillia Permatasari (a) a) Department of Chemical Engineering, Faculty of Engineering, Sriwijaya University, Indonesia *susilaarita[at]yahoo.com Abstract Glycerol, an abundant byproduct of the biodiesel industry, can be converted into economically valuable primary products, namely lactic acid and formic acid, although it still contains other byproducts. Therefore, a large-capacity separation technology, namely distillation, is required. This study studied the separation of lactic acid and formic acid from a glycerol conversion mixture using a variety of methods, namely atmospheric distillation, vacuum distillation, and reactive distillation. The analysis focused on the physical-chemical properties approach and percent recovery. The process began by comparing atmospheric distillation and vacuum distillation methods. The results showed that separation using the vacuum distillation method obtained a density ratio and mass ratio of the mixture in both the condensate and residue that were actually better than the atmospheric distillation method due to the degradation of formic acid and lactic acid at high temperatures and pressures. In addition, it was supported by a greater recovery of lactic acid of 92.363% and a greater recovery of glycerol of 97.211% in the residue in the vacuum distillation method. Further separation of lactic acid was carried out through reactive distillation at varying temperatures and substrate mixtures, reflecting the residue from the previous stage. Lactate recovery increased with increasing temperature up to 125 celsius and then decreased at higher temperatures. Keywords: Glycerol Conversion, Vacuum Distillation, Reactive Distillation, Lactic Acid, Formic Acid Share Link | Plain Format | Corresponding Author (Putra Rajasa)

70	Physical Chemistry	ABS-47
The Effectiveness of Boron and Halide Modified Carbon Nanoparticles (CNPs) for Detecting Polystyrene Microplastics in Aquatic Environments Dzakiyach Aufa Furqony1,a*, Lina Mahardiani1,b 1Department of Chemistry Education, Faculty of Teacher Training and Education, Universitas Sebelas Maret, Indonesia. Abstract Carbon nanoparticles (CNPs) are nanoparticle materials with excellent fluorescence properties and potential applications as sensors. This study aims to investigate the effectiveness of boron and halide (Cl, Br, and I) modified CNPs for the detection of polystyrene microplastics in aquatic environments. The CNPs were synthesized using HNO3 via solvothermal method at 200 C, with pyrene as the carbon source, and subsequently modified with H3BO3, HCl, HBr, and HI. The synthesis produced black powder samples denoted as B-PN, Cl-PN, Br-PN, and I-PN. FTIR analysis confirmed the presence of aromatic ring functional groups of nitrated pyrene, C-B bonds in B-PN, and C-X (halide) bonds in Cl-PN, Br-PN, and I-PN. XRD results indicated that boron and halide doping reduced both the crystallite size and degree of crystallinity due to crystal structure distortion. Photoluminescence analysis showed emission peaks at wavelengths of 500-510 nm, corresponding to the green spectral region. Under UV irradiation at 365 nm, boron and halide doped CNPs were able to detect polystyrene microplastics under various dopant types, solvents, detector masses, and aqueous conditions. The strongest fluorescence emission was observed when nonpolar solvents and larger detector sample masses were used, attributed to van der Waals forces and pi-pi interactions between polystyrene and CNPs. These findings demonstrate that boron and halide modified CNPs have strong potential as simple and effective sensors for the detection of polystyrene microplastics in both aquatic and non-aquatic environments. Keywords: carbon nanoparticles, pyrene, microplastics, sensor, photoluminescence Share Link | Plain Format | Corresponding Author (Dzakiyach Aufa Furqony)

71	Physical Chemistry	ABS-58
Development of TiO2/CuxO Electrodes as Dark Cathode for Photoelectrochemical CO2 Reduction Reaction Nurafni Setiawati, Iman Abdullah, Jarnuzi Gunlazuardi* Department of Chemistry, University of Indonesia *Jarnuzi[at]ui.ac.id Abstract Carbon dioxide reduction reaction (CO2RR) is a promising approach for converting CO2 into valuable gases and liquids while supporting the development of sustainable energy systems. One of the widely explored strategies for CO2RR is the photoelectrochemical (PEC) system, in which the reduction reaction occurs at the dark cathode coupled with photoanode, which can be driven by light energy. In this study, a PEC system was designed using a Reduced-TiO2/BiVO4 photoanode and a TiO2/CuxO cathode, with particular focus on the development of the cathodic material. This research aims to develop TiO2-based electrodes modified with CuxO and to investigate the effect of surface modification on their physicochemical properties and electrochemical performance toward CO2RR. TiO2 was synthesized via anodization method to obtain nanotubes structures, followed by Cu2O deposition onto the TiO2 nanotubes using the electrodeposition technique. Subsequent calcination was performed to convert Cu2O into CuO on the TiO2 surface. Optical property analysis revealed a significant reduction in band gap energy from 3.34 eV for TiO2 to 2.0 eV for TiO2/Cu2O and 1.45 eV for TiO2/CuO, indicating altered electronic properties. The electrochemical activities of TiO2, TiO2/Cu2O, and TiO2/CuO electrodes were evaluated in 0.5 M KHCO3 electrolyte using a three-electrode system. The result is that the TiO2/Cu2O electrode exhibits a more positive potential onset for CO2 reduction compared to the other electrodes, suggesting enhanced catalytic activity. These findings highlight the crucial role of CuxO surface modification in tuning the electronic properties of TiO2-based materials and their potential application in efficient and environmentally friendly CO2 conversion systems. This result also supports the integration of the material into a PEC system based on a Reduced-TiO2/BiVO4 photoanode and a TiO2/CuxO cathode. Keywords: PEC- CO2RR- electrochemistry- electrodeposition- TiO2 nanotubes- TiO2/Cu2O- TiO2/CuO Share Link | Plain Format | Corresponding Author (Nurafni Setiawati)

72	Physical Chemistry	ABS-68
Improved Electrochemical Performance of PLA-Based Solid Polymer Electrolytes through Graphene Oxide Reinforcement Ristika Oktavia Asriza, I Made Arcana, Rachmawati, Sun Theo C L Ndruru Institut Teknologi Bandung Abstract The development of sustainable solid polymer electrolytes has emerged as a critical focus for advancing next-generation lithium-ion batteries. In this work, poly(lactic acid) (PLA), a biodegradable and bio-based polymer, was engineered via the incorporation of graphene oxide (GO) to enhance its ionic and electrical conductivity. PLA/GO composite membranes were fabricated using a solution casting approach with systematically varied GO loadings to elucidate the role of filler concentration on the structural, thermal, and electrochemical properties. The introduction of GO markedly improved the conductivity of PLA, attributed to the abundance of oxygenated functional groups on GO nanosheets that facilitate ion transport and strengthen interfacial interactions within the polymer matrix. X-ray diffraction (XRD) analysis revealed a pronounced reduction in PLA crystallinity, leading to an increased amorphous phase that promotes ion mobility. Morphological observations confirmed a uniform dispersion of GO at optimal loading, whereas higher concentrations induced agglomeration, thereby limiting conductive pathways. Electrochemical impedance spectroscopy (EIS) results demonstrated a substantial enhancement in ionic conductivity compared to pristine PLA, highlighting a strong synergistic interaction between the polymer matrix and GO. Furthermore, the optimized composite membrane exhibited improved thermal stability and mechanical robustness. Overall, this study establishes graphene oxide as an effective conductive nanofiller for enhancing the electrochemical performance of PLA-based electrolytes, offering a promising route toward environmentally sustainable energy storage materials. Keywords: polymer electrolite, poly(lactic) acid, graphene oxide, batteries Share Link | Plain Format | Corresponding Author (Ristika Oktavia Asriza)

73	Physical Chemistry	ABS-74
Synthesis and Characterization of MnFe2O4 Spinel as a Fenton-Like Heterogeneous Catalyst for the Degradation of Rhodamin B Lina Mahardiani (a*), Mustika Della Asti (a), Endang Susilowati (a), Yulianto Agung Rezeki (a), Sulistyo Saputro (a) (a) Chemistry Education, Universitas Sebelas Maret, Surakarta, Central Java 57126 Indonesia *mahardiani.lina[at]staff.uns.ac.id Abstract This research aims to (1) Understanding how to synthesize Fe2O3 and MnFe2O4 materials. (2) Analyzing the characteristics of Fe2O3 and MnFe2O4 materials. (3) Analyzing the effectiveness of MnFe2O4 as a heterogeneous Fenton-like catalyst for the degradation of Rhodamine B dye. (4) Determining the degradation kinetics model of a Fenton-like system using MnFe2O4 for Rhodamine B. The study was conducted using a laboratory experimental method. The results of the study showed that: (1) Fe2O3 and MnFe2O4 , was successfully synthesized- the resulting compounds were reddish-brown and blackish-brown, respectively, were in powder form and can be attracted by magnets. FTIR characterization revealed two main peaks characteristic of Fe-O or O-Fe-O stretching vibrations in Fe2O3 and Mn-O and Fe-O in MnFe2O4 at tetrahedral and octahedral sites. The XRD patterns of Fe2O3 and MnFe2O4 correspond to the JCPDS standard patterns with main peaks at 2theta = 33,10 degrees (104) and 2theta = 33,14 degrees (311), respectively. SEM results of MnFe2O4 reveal surface morphology consisting of particles ranging from spherical to irregular shapes with varying sizes, and the presence of Mn, Fe, and O elements was identified. The surface area of MnFe2O4 was determined to be 6,674 m2/g via BET analysis and indicates the presence of hysteresis, which proves that the MnFe2O4 structure exhibits dominant mesoporous characteristics. (3) MnFe2O4 functions optimally as a catalyst under the following conditions: 25 mL of 9,8 M H2O2, 0,1 g of catalyst, a Rhodamine B concentration of 5 ppm, and a contact time of 60 minutes, achieving a degradation percentage of 73,99%. A concentration of 10 ppm was selected as the midpoint for further research on regeneration, yielding an increasing degradation percentage over 4 regeneration cycles, reaching 98,43%. (4) The degradation kinetics of MnFe2O4 in a Fenton-like system toward Rhodamine B follow pseudo first order kinetics with an R2 value of 0,9809. Keywords: Catalyst, MnFe2O4, Fenton-like, Rhodamine B Share Link | Plain Format | Corresponding Author (Mustika Della Asti)

74	Physical Chemistry	ABS-76
Synthesis and Optimization of MnFe2O4 as a Catalyst for the Degradation of Methylene Blue Dye Putri Aisyah Ali (a*), Mustika Della Asti (a), Lina Mahardiani, S.T., M.Sc., Ph.D. (a) a) Chemistry Education Study Program, Faculty of Teacher Training and Education (FKIP), Universitas Sebelas Maret *putriaisyahali[at]student.uns.ac.id Abstract Spinel ferrite materials, MFe2O4, were synthesized and evaluated as heterogeneous catalysts for the degradation of methylene blue dye. The growing concern over water pollution from textile dye effluents has driven the need for efficient and reusable catalytic systems. In this study, MnFe2O4 were prepared via the coprecipitation method using NaOH as the precipitating agent. The synthesized materials were characterized using FTIR, XRD, BET, SEM-EDX, and UV-DRS, and subsequently tested as catalysts through a Fenton-like oxidation process. MnFe2O4 were successfully obtained as dark brown powders. FTIR analysis confirmed the formation of characteristic metal-oxygen bonds, including Mn-O and Fe-O vibrations in MnFe2O4, consistent with a spinel structure. XRD patterns revealed that both materials adopted a cubic spinel phase with crystallinity values of 53,66% for MnFe2O4, indicating well-defined phase formation. BET measurements yielded specific surface areas of 7,01 m2/g for MnFe2O4. SEM-EDX analysis showed that MnFe2O4 displayed a broader morphological distribution ranging from near-spherical to irregular shapes with varying particle sizes. UV-DRS analysis determined optical band gap values of 2,56 eV for MnFe2O4, classifying the material as semiconductors. Catalytic performance was evaluated by varying reaction time and H2O2 volume. MnFe2O4 demonstrated superior performance, reaching a degradation efficiency of 83.32% at 60 minutes with 8 mL H2O2. This results indicate that spinel ferrite is promising heterogeneous catalysts for dye degradation via the Fenton-like process. Keywords: Spinel Ferrite, Cobalt Ferrite, Manganese Ferrite, Catalyst, Fenton-like, Methylene Blue Share Link | Plain Format | Corresponding Author (Putri Aisyah Ali)

75	Physical Chemistry	ABS-100
The Effectiveness of Activated Carbon-Based PET Bottle Waste Modified With Iron Oxide Toward Congo Red Removal Laelatul Fadilah1,a* and Lina Mahardiani2,b 1Department of Chemistry Education, Faculty of Teacher Training and Eductaion, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Surakarta, Indonesia alaelatulfadilah[at]student.uns.ac.id, bmahardiani.lina[at]staff.uns.ac.id Abstract Water pollution caused by synthetic dyes such as Congo Red (CR) is a serious environmental problem due to their toxic, persistent, and non-biodegradable nature. Meanwhile, the accumulation of polyethylene terephthalate (PET) bottle waste continues to rise and contributes to plastic pollution. This study integrates these two issues by utilizing PET waste as a raw material for activated carbon modified with Fe3O4 to produce an effective, easily separable, and reusable magnetic adsorbent for the removal of Congo Red from aqueous solutions. The synthesized adsorbents include PET-AC, PET-AC/Fe3O4 Oven, and PET-AC/Fe3O4 Furnace, which were characterized using FTIR, XRD, and N&#8322- Adsorption-Desorption Isotherms. The characterization results indicate the formation of characteristic functional groups of activated carbon and Fe-O bands in the modified adsorbents. XRD analysis confirmed the formation of a semi-crystalline Fe3O4 phase with a crystallinity of 6.90% in PET-AC/Fe3O4 Oven and 18.47% in PET-AC/Fe3O4 Furnace. BET analysis showed a surface area of PET-AC of 622.7830 m2/g, which decreased to 323.7633 m2/g and 228.2129 m2/g after Fe3O4 modification due to partial pore closure of the adsorbent. Nevertheless, both modified adsorbents exhibited high adsorption capacity for CR, with PET-AC/Fe3O4 Furnace providing the best performance across all test variations. After four regeneration cycles, the PET-AC/Fe3O4 Furnace still maintained a removal efficiency of 96.729%. Isotherm studies indicate that adsorption follows the Langmuir model (R2 = 0.9770 and 0.9944), while kinetic studies follow the pseudo-second-order model (R2 = 0.9948 and 0.9971), suggesting monolayer adsorption dominated by chemisorption mechanisms. The results of this study indicate that Fe3O4-modified PET waste-based activated carbon has the potential to serve as an effective and sustainable adsorbent for dye wastewater treatment while supporting the utilization of plastic waste within the circular economy concept. Keywords: Activated Carbon, PET, Fe3O4, Adsorption, Congo Red Share Link | Plain Format | Corresponding Author (Laelatul Fadilah)

76	Physical Chemistry	ABS-105
Fabrication Of Electrospun PVA Nanofibers Incorporated With Guava Leaf (Psidium Guajava L.) Extract As An Antibacterial Agent Natasya Shalla Evelin1, Seif Fakih Husein1, Mujtahid Kaavessina2, and Yulianto Agung Rezeki1,* 1Department of Physics Education, Faculty of Teacher Training and Education, Universitas Sebelas Maret, Jalan Ir. Sutami 36A, Surakarta 57126, Indonesia, 2Department of Chemical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Jalan Ir. Sutami 36A, Surakarta 57126, Indonesia. Abstract Wound infection caused by bacterial contamination remains a major challenge in wound management, particularly with the increasing prevalence of antimicrobial resistance. Consequently, considerable attention has been directed toward the development of alternative antibacterial agents. Among these, Psidium guajava (guava) leaf extract has attracted considerable attention due to its antimicrobial properties and has been incorporated into electrospun nanofibers. However, previous studies have mainly focused on polyurethane-based systems and have not systematically investigated the effect of extract loading on nanofiber properties and antibacterial performance. Accordingly, this study investigated the effect of polyvinyl alcohol (PVA)/guava leaf extract (GLE) mass ratio on the physicochemical properties and antibacterial activity of electrospun nanofibers for wound dressing applications. PVA/GLE solutions with mass ratios of 10:0, 7:1, 6:1, and 5:1 were electrospun and characterized by SEM, XRD, FTIR, water contact angle, mechanical testing, and antibacterial assays against S. aureus and P. aeruginosa. Increasing GLE content reduced the average fiber diameter from 172.9 +- 29.9 nm to 102.0 +- 19.1 nm. XRD and FTIR analyses indicated reduced crystallinity and intermolecular interactions between PVA and GLE, while water contact angle measurements confirmed enhanced hydrophilicity. The 5:1 PVA/GLE nanofibers exhibited the highest tensile strength (9.79 MPa) and elongation at break (75.66%) and showed inhibition zones of 8.85 mm +- 0.07 and 7.83 mm +- 0.16 against S. aureus and P. aeruginosa, respectively. These findings demonstrate that GLE incorporation effectively tailors the physicochemical properties and antibacterial performance of electrospun PVA nanofibers, highlighting their potential as natural antibacterial wound dressing materials. Keywords: Guava leaf extract- polyvinyl alcohol- electrospinning- nanofibers- antibacterial activity. Share Link | Plain Format | Corresponding Author (Yulianto Agung Rezeki)

77	Sciences and STEM Education	ABS-10
Development of Authentic Inquiry Project-Based Ecology Learning to Improve Critical Thinking Skills Geterudis Kerans(*1), Oktavianus Deke(2), Ni Wayan Prawita(3) Science education Study Program, Faculty of Teacher Training and Education, Universitas Katolik Weetebula, Indonesia. Abstract The teaching process in higher education must emphasise the four basic pillars of learning, whereby learning is not only about acquiring knowledge but also about doing something, becoming something and having an impact on social life. Learning at universities must be able to emphasise the importance of these pillars of learning through learning that emphasises critical thinking. Critical thinking skills provide space for students to critically examine problems, analyse and evaluate them using scientific procedures so as to find the right solution. Higher education institutions, as providers of workers who will compete in the global world, need to prepare their students with critical thinking skills. One of the efforts made is to innovate lectures by using authentic inquiry project-based learning. This learning innovation raises real-world problems as part of the learning process carried out through scientific procedures in a meaningful project. The purpose of this study is to develop learning instruments based on authentic inquiry projects on Ecology material to improve students^ critical thinking skills. This study uses the R & D method with the 4D model (Define, Design, Develop, and Dissemination). Data collection was carried out through literature studies, field observations, and the development of learning instruments based on authentic inquiry projects. The results of the first year of research were learning instruments (RPS, student worksheets, assessment sheets, and critical thinking skills test questions) on Ecology material. The resulting learning instruments were declared suitable for use in improving students^ critical thinking skills in Ecology material. The impact of this research is the availability of instruments that are ready to be used as learning innovations in teaching Ecology material. Keywords: Authentic_Inquiry_Project- Ekologi- Critical thinking Skills Share Link | Plain Format | Corresponding Author (Geterudis Kerans)

78	Sciences and STEM Education	ABS-20
Implementation of the STREAM Approach through Mirasaki Sweet Potato Based Product Development to Enhance Contextual Food Science Learning in Junior High School Rifadiyah Nurul Khotimah, Ririh Widowati, Ira Sukmawati Abidin, Tri Wahyu Agustina, Ade Yeti Nuryantini UIN Sunan Gunung Djati Abstract The utilization of local food resources in junior high school learning remains relatively limited, despite its strategic potential to strengthen the relevance of science education to real-life contexts. Integrating local food into project-based activities not only supports students^ conceptual understanding of scientific principles but also fosters awareness of local wisdom and sustainable resource use. One local commodity with considerable potential is mirasaki sweet potato, which contains anthocyanin pigments as natural antioxidants and serves as a source of complex carbohydrates beneficial to health. This study implemented the STREAM (Science, Technology, Religion, Engineering, Arts, and Mathematics) approach in developing Putri Noong made from mirasaki sweet potato as a medium for food science learning. In the science component, observations were conducted on starch gelatinization, physical and chemical changes due to heating, and the stability of anthocyanin pigments. The technology component involved the application of appropriate processing and steaming techniques to achieve optimal product characteristics. The religion dimension was integrated through reflection on halal principles, hygiene, and ethical food production practices. The engineering aspect focused on designing systematic procedures and controlling variables to ensure product consistency. The arts element was reflected in creative presentation and the aesthetic value of the natural purple color, while mathematics was applied in measuring ingredient proportions and calculating estimated nutritional values accurately. The findings indicate that the product demonstrated stable natural color, soft texture, and good acceptance among students. The implementation of the STREAM approach supports systematic, interdisciplinary, and contextual learning while promoting the meaningful use of local food resources in science education. Keywords: STREAM, local food, mirasaki sweet potato Share Link | Plain Format | Corresponding Author (Rifadiyah Nurul Khotimah)

79	Sciences and STEM Education	ABS-22
In Silico Analysis of Pandan Leaves (Pandanus amaryllifolius) as Potential Alpha-1-Adrenergic Receptor Agonists for Hypotension Therapy Rahadian Zainul(a*), Iffat Syafiqoh Afif (b), Faiqa Haura Tsagifa (c) (a) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Padang, Air Tawar Barat 25132, Padang, Indonesia. Center for Advanced Material Processing, Artificial Intelligence, and Biophysics Informatics (CAMPBIOTICS), Universitas Negeri Padang, Air Tawar Barat 25132, Padang, Indonesia. INTI International University, Negeri Sembilan, 71800, Malaysia. Email: *rahadianzmsiphd[at]fmipa.unp.ac.id Orcid: 0000-0002-3740-3597 (b) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padang State University, Padang, Indonesia Orcid: 0009-0000-7800-0260 (c) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padang State University, Padang, Indonesia. Orcid: 0009-0009-3448-502X Abstract Hypotension is characterized by systolic blood pressure below 90 mmHg and diastolic blood pressure below 60 mmHg. This condition significantly increases the risk of falls, syncope, and cardiovascular complications, particularly among the elderly. While pharmacological interventions such as midodrine are effective, they are frequently associated with adverse side effects, necessitating the exploration of safer natural alternatives. This study evaluated the potential of bioactive alkaloids from Pandan leaves (Pandanus amaryllifolius) as antihypotensive agents through an in silico molecular docking approach. Ten bioactive compounds were screened against the alpha-1-adrenergic receptor (PDB ID: 7B6W) using midodrine as a reference ligand. The results demonstrated that three lead compounds, specifically pandamarilactonines A, pandamarilactone 32, and pandanusine B, exhibited superior binding affinities compared to midodrine, with docking scores reaching -7.4760 kcal/mol. Molecular interaction analysis revealed stable hydrogen and ionic bonding with key residues such as GLU199 and TRP184. Furthermore, drug-likeness and ADMET evaluations confirmed that these candidates adhere to Lipinski and Veber rules, showing high intestinal absorption rates between 77% and 99% with no predicted hepatotoxicity. These findings provide a compelling scientific basis for the development of pandan-derived alkaloids as high-efficacy herbal therapies for hypotension with a potentially lower risk of side effects. Although these computational results are promising, further in vitro and in vivo studies are essential to validate their clinical bioactivity and safety. Keywords: Pandanus amaryllifolius, hypotension, molecular docking, alpha-1-adrenergic receptor, in silico Share Link | Plain Format | Corresponding Author (Rahadian Zainul)

80	Sciences and STEM Education	ABS-31
Identification of Manilkara zapota Phytochemicals as Novel RANKL Inhibitors for Osteoporosis Therapy: An Integrated Computational Study Iffat Syafiqoh Afif- Rahadian Zainul- Intan Elwis Khairina Muzia (a) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padang State University, Padang, Indonesia Orcid: 0009-0000-7800-0260 (b) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Padang, Air Tawar Barat 25132, Padang, Indonesia. Center for Advanced Material Processing, Artificial Intelligence, and Biophysics Informatics (CAMPBIOTICS), Universitas Negeri Padang, Air Tawar Barat 25132, Padang, Indonesia. INTI International University, Negeri Sembilan, 71800, Malaysia. Orcid: 0000-0002-3740-3597 (c) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padang State University, Padang, Indonesia Abstract Osteoporosis remains a significant global health challenge characterized by systemic bone density depletion and heightened fracture risks. This condition necessitates the discovery of potent inhibitors for the RANKL (Receptor Activator of Nuclear Factor-kappa B Ligand) signaling pathway. Due to the adverse effects of synthetic therapeutics, this study investigated the anti-osteoporotic potential of ten bioactive compounds derived from Manilkara zapota. These compounds include betulinic acid, caffeic acid, chlorogenic acid, gallic acid, germanicol, L-arabinose, myricetin, beta-amyrin, myricetin-3-O-glucoside, and oleanolic acid. A systematic in silico approach was employed to evaluate these phytochemicals. Molecular docking simulations were performed against the RANKL protein (PDB ID: 3URF) using AutoDock Vina, with the monoclonal antibody Denosumab serving as the reference ligand. Quantitative results revealed that chlorogenic acid exhibited the most formidable binding affinity among the phytochemicals with a docking score of -5.4216 kcal/mol (RMSD 1.1338 A), followed by germanicol (-4.8063 kcal/mol- RMSD 1.6254 A) and myricetin (-4.3947 kcal/mol- RMSD 1.3269 A). Comparatively, Denosumab yielded a binding energy of -6.1829 kcal/mol. All tested compounds demonstrated high conformational stability with RMSD values consistently below the 2.0 A threshold. Furthermore, ADMET profiling and drug-likeness evaluations confirmed that the lead phenolic constituents strictly adhered to Lipinski^s Rule of Five, exhibiting favorable pharmacokinetic parameters and minimal predicted toxicity. These findings suggest that M. zapota phytochemicals, particularly chlorogenic acid, possess significant potential as natural RANKL inhibitors. This research provides a theoretical foundation for further in vitro and in vivo validations in developing plant-based alternatives for metabolic bone disease management. Keywords: Manilkara zapota, RANKL inhibitor, molecular docking, osteoporosis, chlorogenic acid, ADMET profiling. Share Link | Plain Format | Corresponding Author (Iffat Syafiqoh Afif)

81	Sciences and STEM Education	ABS-78
The Effectiveness of an Illustrated Digital Storybook in Enhancing Junior High School Students Scientific Literacy on Ecology and Biodiversity Hendra Ramadhan, Sulistyo Saputro, Lina Mahardiani Masters Program in Science Education Faculty of Teacher Training and Education Universitas Sebelas Maret Surakarta Indonesia Abstract This study aims to analyze the effectiveness of an illustrated digital storybook focusing on environmental conservation to improve junior high school students scientific literacy in ecology and biodiversity topics. The study employed a quasi experimental pretest posttest nonequivalent control group design involving one experimental class and one control class of seventh grade students. The population consisted of Grade VII students from two public junior high schools in Sukoharjo Regency Indonesia namely SMP Negeri 1 Mojolaban and SMP Negeri 2 Baki. Two intact classes were selected as samples with one class assigned as the experimental group and the other as the control group. The experimental group received instruction using the illustrated digital storybook integrated with Problem Based Learning while the control group received conventional instruction. Scientific literacy was measured using a 12 item essay test based on scientific literacy indicators. Data were analyzed using an independent one tailed t test and normalized gain. The results indicate that students who learned using the illustrated digital storybook achieved significantly higher scientific literacy scores than those receiving conventional instruction p less than 0.05 with normalized gain in the moderate to high category. The findings demonstrate that integrating narrative visual digital media with contextual environmental issues effectively enhances conceptual understanding scientific reasoning and evidence based decision making. The illustrated digital storybook is therefore effective for supporting scientific literacy development in secondary science education. Keywords: scientific literacy- illustrated e book- environmental education- ecology and biodiversity- quasi experimental design Share Link | Plain Format | Corresponding Author (Hendra Ramadhan)

82	Sciences and STEM Education	ABS-95
Innovation in Residential Electrical Installation Design Projects to Enhance Students^ Creative Thinking Skills and Creativity through STEM-PjBL Learning Habibi Salam, Jeany Octaviany ,Irfan Syafar Farouq, Alis Siti Maesaroh , Yulia Sukmawardani , Sumiyati Saadah, Ade Yeti Nuryantini Master of Science Education Study Program, Postgraduate UIN Sunan Gunung Djati Bandung Abstract This study aimed to analyze the implementation of the Science, Technology, Engineering, and Mathematics-Project Based Learning (STEM-PjBL) model in enhancing the creativity of ninth-grade junior high school students through a residential electrical installation design project. The study sought to bridge the gap between theoretical concepts of electricity and practical applications requiring the integration of spatial, technical, and aesthetic understanding. A quantitative approach with a pre-experimental one-group pretest-posttest design was employed. The research participants consisted of 30 students from SMPN 2 Solokanjeruk, Bandung Regency, during the 2025/2026 academic year. Data were collected using pretest and posttest assessments, creativity observation sheets covering fluency, flexibility, and originality, and a product assessment rubric based on the criteria of novelty and usefulness. The results indicated that the overall improvement in students^ understanding was categorized as moderately effective, with an average N-Gain score of 46.53%. In terms of individual distribution, 10% of students achieved a high improvement category, 66.7% achieved a moderate improvement category, and 23.3% achieved a low improvement category. Qualitative analysis revealed that the electrical installation design project successfully stimulated students^ creativity, particularly in the aspects of fluency and originality, as students were able to generate unique and functional electrical solutions. In conclusion, the STEM-PjBL model was found to be effective in strengthening students^ 21st-century skills and scientific literacy through authentic problem-solving activities in secondary school settings. Keywords: STEM-PjBL, creativity, project-based learning, electrical installation design, scientific literacy, 21st-century skills. Share Link | Plain Format | Corresponding Author (Yulia Sukmawardani)

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