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The Synergistic Enhancement of Electromagnetic Interference Shielding Polymer Composites using Carbon Nanofiber-Metal Oxide Hybrid Fillers Dini Deviana Saputri; Teguh Endah Saraswati; Wijang Wisnu Raharjo
ALCHEMY Jurnal Penelitian Kimia Vol 21, No 2 (2025): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.21.2.97322.224-240

Abstract

In this modern era, humans cannot be separated from utilizing electronic devices. The unwanted noise or disturbance problem in electronic devices is majorly caused by Electromagnetic Interference (EMI). Recent technology and materials are being developed to manufacture EMI shielding composites. Carbon nanomaterial-based composites have become a very attractive material because of their lightweight, incredible mechanical, thermal, and conductivity properties. Carbon nanofibers (CNFs) and metal oxides are promising combination materials that reveal unique properties of both components to enhance shielding effectiveness. This combination of CNFs and metal oxides results in a synergistic effect, where the conductive CNFs enhances the reflection of EMI, and the metal oxides contribute to the absorption and attenuation of the waves. In this review article, the authors focus on the extensive discussion about the synthesis method of producing CNFs, some studies that combine CNFs and metal oxide, and some reports about using CNFs-metal oxide as a hybrid filler in the EMI shielding composites.
Effect of Garlic Powder Addition to Gelatin Biocomposite on Its Antibacterial Activity Pramudita Putri Kusuma; Ganjar Fadillah; Husna Syaima; Teguh Endah Saraswati
ALCHEMY Jurnal Penelitian Kimia Vol 12, No 1 (2016): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.12.1.930.1-13

Abstract

The addition of garlic powder to gelatin from chicken claw waste was potentially developed as a natural preservative in food, especially for meat. Preparation of gelatin/garlic biocomposite was performed in three stages: synthesis of gelatin from chicken claw, garlic powder preparation as allicin source and preparation of biocomposite gelatin/garlic. The preparation of dry biocomposites was done by weighing the gelatin and garlic powder in weight ratio of 1 : 1 and 1 : 2 (w/w) in the total mass of 0.75 grams. For wet biocomposite preparation, the mixture of the powder was solved in 5 mL of lactic acid 2 %. Functional groups of gelatin, garlic and biocomposite were analyzed by fourier transform infrared spectroscopy (FTIR). The antibacterial activity of biocomposite against Staphylococcus aureus were tested using disc diffusion method. This test was performed on garlic powder, solvent and gelatin/garlic biocomposites powder in the ratio of 1 : 1 and 1 : 2 in 2 % lactic acid solvent. The biocomposite with a weight ratio of gelatin : garlic of  1 : 1 had the optimum diameter of inhibition zone. The effectiveness of biocomposite gelatin/garlic as natural preservative applied in meat was also physically studied by organoleptic analysis. Organoleptic analysis through the hedonic test was conducted on the parameters of color, smell, and texture of gelatin/garlic biocomposites-coated meat. The results showed that the addition of garlic can increase the effectiveness of gelatin as a natural preservative of meat for four days stored in closed packaging at room temperature.
Effectiveness of Gelatin Extracted from Chicken Claws as A Natural Preservatives for Beef and Fish Ganjar Fadilah; Pramudita Putri Kusuma; Teguh Endah Saraswati
ALCHEMY Jurnal Penelitian Kimia Vol 10, No 2 (2014): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.10.2.544.195-206

Abstract

Gelatin  has  been  successfully  extracted  from  chicken  clawsby  acid  hydrolysis method through four major stages of degreasing, demineralization, extraction and drying. The yield of  extracted  gelatin obtained  from wet chicken claws  was about 6.21  %  (w/w). The  effectiveness  of  gelatin  as  preservative  applied  in  beef  and  fish  was  physically, chemically and microbiologically  studied  by  organoleptic  analysis,  peroxide test, bacteria inhibition  test  and  number  calculation, respectively. Organoleptic analysis by hedonic  test shows  there  were significant  differences  for  color  and  texture  parameters  between  gelatin coated  samples  and control  samples  at  concentrations  of  1:1  (w/w).  Peroxide number analysis  by  iodometry  indicates  the  use  of  gelatin  in  the  preservation  of  meat  and  fish decreased the oxidation number. The result of inhibition test againts Staphylococcus aureus bacteria  shows  the  gelatin  concentration  of  20  %  provided  greatest  halo  zone  diameter (inhibitory  region)  as  19.44  ±  2.11  mm. The colony bacteria test shows the use of gelatin potentially  inhibited  the growth  of  bacteria  up to  75  %.  Overall,  the results  conclude  that gelatin  extracted from chicken claws  has the potential  activities  as a  natural preservative for beef and fish.
The Effect of Fe Pillaring and Mg Intercalating into Bentonite Structure Dian Maruto Widjonarko; Edi Pramono; Sentot Budi Rahardjo; Sayekti Wahyuningsih; Teguh Endah Saraswati
Jurnal Kimia Sains dan Aplikasi Vol 29, No 2 (2026): Volume 29 Issue 2 Year 2026
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.29.2.101-110

Abstract

Bentonite clay particles, measuring less than 2 μm, comprise stacked layers of tetrahedral and octahedral units in a 2:1 configuration (T-O-T). These negatively charged layers were subsequently neutralized with cations. However, the exchange or modification of the cation affects its structure and properties. This study investigates the effect of Fe-ion pillaring on the bentonite layer and the intercalation of Mg ions into Fe-pillared bentonite via ion exchange. The materials were characterized using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM–EDX) to observe surface morphology and elemental composition, Particle Size Analyzer (PSA) to observe average size and size distribution of particle, Fourier-Transform Infrared Spectroscopy (FTIR) to identify the active site and layer structure, and X-ray Diffraction (XRD) to determine their structural and compositional changes. The results confirm the pillaring treatment effect on a higher average particle size of 469.3 nm, with a polydispersity index (PDI) of 0.495, compared to natural bentonite (414.8 nm and 0.586 nm, respectively). Meanwhile, the intercalating treatment showed a lower average particle size of 433.4 nm and a PDI value of 0.613. FTIR identified the silanol and siloxane functional groups, as well as the aluminosilicate layer. Pillaring by Fe2O3 increased the basal spacing of bentonite from 13.6 Å to 17.35 Å, as indicated by the shift of characteristic bentonite peaks to lower 2θ angles. However, intercalation by MgO into Fe-pillared bentonite actually slightly decreased the basal spacing to 15.16 Å. Meanwhile, Mg intercalation occurred within the interlayer of the aluminosilicate layer, resulting in a peak shift toward higher 2θ angles and an increase in crystallinity to 58.924%, compared with Fe-pillared bentonite (45.376%). This phenomenon is likely related to the presence of the Mg metal intercalant, which has basic properties and can attract the aluminosilicate sheets.
Chemical Study of Mordanting and Fixation Processes in Indigo, Sappanwood, and Tannin Natural Dyes Using Visual and UV-Vis Spectroscopic Analysis Sayekti Wahyuningsih; Rahmawati Rahmawati; Djuminah Djuminah; Sri Murni; Nisaul Hasanah Abdul Rosyad; Teguh Endah Saraswati; Edi Pramono; Widyan Muhammad Naufal; Isna Nurmilatul Azizah; Rizqi Apriliyani; Nadia Octaviani Faiq Salsabila
G-Tech: Jurnal Teknologi Terapan Vol 10 No 2 (2026): G-Tech, Vol. 10 No. 2 April 2026
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/g-tech.v10i2.9165

Abstract

Ecoprint is an eco-friendly textile dyeing technique whose color quality is strongly influenced by mordanting and fixation processes. However, inconsistent mordant–fixative systems often result in unstable color intensity and poor standardization. This study aimed to evaluate the effect of different mordant and fixative combinations on the color characteristics of ecoprint fabrics dyed with indigo (Indigofera tinctoria), sappanwood (Caesalpinia sappan), and tannin extracts. Cotton fabrics were treated with either conventional mordant or color mordant, followed by fixation using vinegar, bone lime, lime, clear ferrous sulphate, or ferrous sulphate. Color properties were analyzed using UV-Vis spectroscopy (200-800 nm) and RGB evaluation. Iron-containing mordant systems significantly enhanced absorbance intensity in the visible region. It reduced the RGB lightness values, indicating deeper, more stable colors. Indigo showed maximum absorption at 647-672 nm, with the darkest blue obtained with the color mordant combined with ferrous sulphate fixation. Sappanwood showed maximum absorbance in the 482-491 nm range, under iron-assisted treatments. Tannin dyeing produced the most pronounced darkening effect due to tannin–iron complex formation. Overall, iron-assisted mordant–fixative systems under controlled pH conditions provided the most optimal and reproducible color performance, offering a scientific basis for standardizing the ecoprint process in sustainable textile production.
Pengaruh Bentonit terhadap Pembentukan Fasa Polimorf dan Sifat Termal Membran Hibrida Poliviniliden Fluorida/Bentonit Edi Pramono; Rosid Eka Mustofa; Ozi Adi Saputra; Yulianto Adi Nugroho; Deana Wahyunigrum; Cynthia Linaya Radiman; Sayekti Wahyuningsih; Teguh Endah Saraswati; Sentot Budi Rahardjo; Witri Wahyu Lestari; Dian Maruto Widjonarko; Ari Handono Ramelan
ALCHEMY Jurnal Penelitian Kimia Vol 17, No 2 (2021): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.17.2.46136.177-184

Abstract

Kajian struktur dan degradasi termal pada membran hibrida poliviniliden fluorida (PVDF)/lempung bentonit (BNT) telah dilakukan. Penelitian ini bertujuan mengetahui pengaruh penambahan BNT terhadap pembentukan fasa PVDF dan sifat termalnya. Membran hibrida PVDF/lempung BNT dibuat dengan metode inversi fasa. Membran yang dihasilkan dikarakterisasi dengan attenuated total reflectance fourier transform infrared (ATR-FTIR), x-ray diffraction (XRD), dan differential scanning calorimetry (DSC). Hasil penelitian menunjukkan membran PVDF/BNT memiliki struktur polimorf PVDF fasa α dan β yang terkonfirmasi dari data FTIR dan XRD. Data DSC menunjukkan penurunan nilai titik leleh (Tm) dengan penambahan BNT, dan dengan rentang suhu pelelehan yang lebih kecil. Kristalisasi PVDF terjadi secara isothermal dan adanya BNT menghasilkan titik kristalisasi (Tc) pada suhu yang lebih tinggi dibandingkan membran PVDF murni. Analisis termal dengan DSC memberikan informasi komprehensif pelelehan dan kristalisasi dari polimorf PVDF pada matriks membran.Effect of Bentonite toward Polymorph Phase Formation and Thermal Properties of Polyvinylidene Fluoride/Bentonite Hybrid Membranes. The study of the structure and thermal properties of PVDF/bentonite (BNT) hybrid membranes has been carried out. This study aims to determine the effect of BNT addition on the phase formation and thermal properties of the PVDF. In this study, PVDF/BNT hybrid membranes were prepared through the phase inversion method. The resulting membrane was characterized by Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), x-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results showed that the PVDF/BNT membrane has a PVDF polymorph structure with α and β phases confirmed by FTIR and XRD data. The DSC data showed that the addition of BNT decrease of the melting point (Tm) and with a smaller melting temperature range. PVDF polymorph crystallization occurs isothermally and the presence of BNT produces a crystallization point (Tc) at a higher temperature than pristine PVDF membrane. Thermal analysis with DSC provides comprehensive information on melting and crystallization of PVDF polymorphs in the membrane matrix.
Sintesis Carbon Nanofoam dan Karakteristiknya Nuryah Muchlisha; Dian Maruto Widjonarko; Teguh Endah Saraswati
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 1 (2023): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.1.64499.108-122

Abstract

Karbon memiliki kemampuan untuk membuat jaringan ikatan hibridisasi sp, sp‒sp2, sp2, sp3, dan sp2‒sp3,sehingga karbon terdapat dalam banyak bentuk alotrop seperti grafit, diamond, graphene, nanofiber, nanofoam, dan nanotube. Carbon nanofoam (CNF) terbentuk dari atom karbon yang terikat secara sp2 dan sp3. CNF memiliki struktur sel terbuka yang saling berhubungan, densitas yang sangat rendah, stabilitas termal yang tinggi, dan porositas yang tinggi. CNF dapat diperoleh dengan menggunakan berbagai metode seperti chemical vapor depositon, laser ablsasi, arc-discharge, dan pirolisis. Sintesis dengan berbagai jenis sumber karbon dan keadaan eksperimen menghasilkan material yang memiliki berbagai ukuran, luas permukaan, dan strukturnya. Struktur CNF terdiri dari dua jenis berdasarkan pola tepi strukturnya yaitu zigzag dan armchair. Hasil karakterisasinya menunjukkan bahwa CNF lebih banyak mengandung karbon dengan hibridisasi sp2 dengan struktur yang berinterkoneksi satu sama lain dan memiliki densitas yang sangat rendah. Selain itu, material ini juga memiliki pori dalam ukuran mesopori dan luas permukaan yang tinggi. Sifat unik yang dimiliki oleh CNF berpotensi diaplikasikan dalam berbagai bidang seperti filter, superkapasitor, dan energy storage. Synthesis of Carbon Nanofoam and Its Characteristics. Carbon can create sp, sp‒sp2, sp2, sp3, and sp2‒sp3 hybridized bond networks, which make carbon in many allotropes forms such as graphite, diamond, graphene, nanofiber, nanofoam, and nanotubes. Carbon nanofoam  (CNF) is formed by sp2 and sp3 bonded carbon atoms. CNF has an interconnected open-cell structure, very low density, high thermal stability, and high porosity. CNF is obtained using several methods, such as laser ablation, arc-discharge, chemical vapor deposition, and pyrolysis. Synthesis with various types of carbon sources and experimental conditions resulted in materials having various sizes, surface areas, and structures. The structure of CNF consists of two edge pattern types, including zigzag and armchair. The characterization results show that CNF contains more interconnected carbon with sp2 hybridization and has a very low density. In addition, this material also has pores in the mesoporous size and high surface area. The unique properties of CNF provide potential applications in various fields, such as filters, supercapacitors, and energy storage.
Use of Battery Carbon as Electrodes in Arc Discharge Method for Fabrication of Carbon-Modified TiO2. Isya Fitria Andhika; Carissa Hertiningtyas; Ardian Aji; Alifia Desy; Teguh Endah Saraswati; Patiha Patiha
ALCHEMY Jurnal Penelitian Kimia Vol 10, No 2 (2014): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.10.2.542.186-194

Abstract

Fabrication with carbon-modified TiO2 by arc  discharge  method  in  liquid  medium has  been  studied.  This  research  was  performed  in  two  steps  including  fabrication  and characterization.  This  fabrication  was  done  by  arcdischarge  method  with  graphite electrodes from dry cell batteries and liquid medium suspension of TiO2 in ethanol 30, 50 and  70  %.  A  strong  current  was  applied  to  electrode  as  10 -50  A  (20-40  V). Nanocomposites formed  on  the  liquid  medium  surface  were  collected  and  characterized using X-ray  diffraction (XRD),scanning  electron  microscope (SEM)  dan energy  dispersive spectroscopy (EDS) to determine crystallinity, surface morphology and the constituent elements, respectively.  XRD  data  shows  that the  most  effective  fabrication  TiO2/Karbon by  liquid medium in ethanol 50  %  indicated  from  the formation of a new peak with high intensity  of TiC on 2Ɵ= 36.02 °. SEM data shows that the morphology of each aggregated TiO2/Karbon  compared  to  the  morphology  of  TiO2. In  addition,  EDS  data  shows  the presence of the element carbon, titanium and oxygen  in the same area  indicating that the successful formation of composite material between TiO2 dan carbon.
Preparation and Characterization of Carbon/Si Nanocomposites Synthesized by Chemical Vapor Deposition (CVD) Using SiC and SiO2 Retno Duwi Hardini; Teguh Endah Saraswati; Sentot Budi Rahardjo; Alaa Keshtta
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.80438.218-225

Abstract

Carbon-based nanocomposite materials have attracted the attention of researchers in the last decade due to their unique properties applicable in wide applications. This study aims to synthesize and study the characteristics of the carbon-based nanocomposite material produced using the chemical vapor deposition (CVD) method with SiC and SiO2. The CVD process was carried out at 900 ℃ in a vacuum with flowing argon, hydrogen, and acetylene gases. The CVD process produced nanocomposites with more sp3 hybridized carbon atoms, as indicated by the D peak in the Raman spectra. The diffraction pattern analyses show that the resulting carbon powder nanocomposite growth with SiC powder (CSiC) reveals a carbon diffraction peak C(002) and has an elongated form confirmed by an electron microscope. In comparison, the resulting carbon powder nanocomposite growth with SiO2 powder (CSiO2) has a spherical form and presents a carbon diffraction peak C(002). CSiC nanocomposites showed both symmetric and asymmetric C‒H stretching. In FTIR data, CSiO2 nanocomposites show more intense O‒H group peaks but lower-intensity C‒H group vibrations.
Lucutan Plasma Pijar Korona dengan Variasi Tegangan untuk Degradasi Metilen Biru kusumandari kusumandari; Teguh Endah Saraswati; Nor Shalina Saputri
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 9, No 01 (2019): April
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (556.495 KB) | DOI: 10.13057/ijap.v9i01.29790

Abstract

Teknologi plasma merupakan metode pengolahan limbah yang cukup menjanjikan. Dalam penelitian ini, lucutan plasma dihasilkan dari dua buah elektroda jarum stainless steel yang dipasang paralel dan dihubungkan dengan tegangan tinggi bolak-balik (AC) sebesar 8.5 – 11.5 kV. Metilen biru digunakan sebagai larutan model. Elektroda berada sekitar 2 mm di atas larutan yang diletakkan pada magnetic stirrer dengan kecepatan 6 rpm. Waktu perlakuan yang digunakan adalah 2, 4, 6, 8, dan 10 menit untuk setiap tegangan. Karakteristik larutan meliputi absorbansi, pH dan suhu diukur sebelum dan sesudah perlakuan untuk mengetahui pengaruh tegangan dan lama waktu perlakuan plasma. Hasil yang didapat, absorbansi dan pH turun seiring kenaikan tegangan dan lama waktu perlakuan, sedangkan suhu akan semakin naik.
Co-Authors Abdul Basith Abdurrahman, Ahmad Faruq Abu Masykur Abu Masykur Achmad Bahrudin Agus Ramelan Ahmad Faruq Abdurrahman Ahmad Qusnudin Akihisa Ogino Alaa Keshtta Alifia Desy Alifia Desy, Alifia Amalia Amalia Amalia Amalia Aprilia, Ayu Ardian Aji Ardian Aji, Ardian Ari Handono Ramelan Asy Syifa Labibah Athaya Cantia Putri Atmanto Heru Wibowo Candra Purnawan Carissa Hertiningtyas Carissa Hertiningtyas, Carissa Cynthia Linaya Radiman Dana - Praseptiangga Davit Dhruv Deana Wahyunigrum Dendy, Dendy Dian Maruto Widjonarko Dian Maruto Widjonarko Dian Maruto Widjonarko Didik Prasetyoko Dielsa Eka Kuswari Dini Deviana Saputri Djuminah Djuminah Dwi Teguh Rahardjo Dwidjono Hadi Darwanto Edi Pramono Edi Pramono Edi Pramono Edi Pramono Ellysa Amelia Putri Fajar Rakhman Wibowo Faradilla, Radianita Feri Adrianto Fitriana, Dina Ganjar Fadilah Ganjar Fadillah Ganjar Fadillah, Ganjar Hamzah Fansuri Husna Syaima Ida Setiarini Ika Uswatun Hasanah Ikrima Nur Hayati Ilma Fadilah Indah Retnosari Irfani, Hasna Haifa Irwan Iftadi Isa Anshori Isna Nurmilatul Azizah Isnaeni Isnaeni Isya Fitri Andhika, Isya Fitri Isya Fitria Andhika Jeesica Hermayanti Pratama Kemala, Yusnadia Kusumandari Kusumandari Kusumandari Kusumandari Kusumandari, Kusumandari Kusumawardani - - Lestar, Witri Wahyu Lestari, Witri Wahyu Maria Ulfa Masaaki Nagatsu Melina, Dika Caesar Miftahul Anwar Miftahul Anwar Mohammad Rifqi Ihsan Mudjijono Mudjijono Muhammad Rifqi Ihsan Mukti, Rino Rakhmata Murni - Ramli Nadia Octaviani Faiq Salsabila Naufal, Widyan Muhammad Nestri Handayani, Nestri Nisaul Hasanah Abdul Rosyad Nor Shalina Saputri Nugroho, Roshid Adi Nuryah Muchlisha Nuzula, Rifania Aura Oktaviana Dewi Indah Prasiwi Oktaviana Dyah Mayasari Ozi Adi Saputra Patiha Patiha Patiha Patiha, Patiha Pramudita Putri Kusuma Pramudita Putri Kusuma Pramudita Putri Kusuma, Pramudita Putri Pratama, Jeesica Hermayanti Puspitasari, Melani Puji Rahayu Rahayu Rahmawati Rahmawati Retno Duwi Hardini Rizka Lailatul Rohmah Rizqi Apriliyani Roro Ernia Prawithasari Rosid Eka Mustofa Saputri, Dini Deviana Sari, Fitri Nela Sayekti Wahyuningsih Sayekti Wahyuningsih Sayekti Wahyuningsih Sayekti Wahyuningsih Sentot Budi Rahardjo Sentot Budi Rahardjo Sentot Budi Rahardjo Sentot Budi Rahardjo Sentot Budi Raharjo Sri Hastuti Sri Murni Suciati - - Suharbiansah, Rujito S. R. Sulistyo - Saputro Venny, Venny Wega Trisunaryanti Widyan Muhammad Naufal Wijang Wisnu Raharjo Wijang Wisnu Raharjo Witri Wahyu Lestari Wulandari, Resa Yudha Pratama Putra Yudi - Rinarto Yuliana Pratiwi Yulianto Adi Nugroho Yuliati Herbani Yuvita Eka Pertiwi Zahar, Intan Zetadini, Reza