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All Journal Jurnal Ilmu Dasar Jurnal Sains Materi Indonesia Alchemy : Journal of Chemistry Jurnal Matematika & Sains SEMIRATA 2015 ALCHEMY Jurnal Penelitian Kimia Indonesian Journal of Chemistry Molekul: Jurnal Ilmiah Kimia
Cynthia Linaya Radiman
Program Studi Kimia, Institut Teknologi Bandung, Bandung
Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Education Energy Environmental Science Materials Science & Nanotechnology Mathematics

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Sintesis Kopoliester dari ε- Kaprolakton dan 2,2-dimetil-1,3-Propandiol: Prepolimer Alternatif untuk Sintesis Poliester Berat Molekul Tinggi M. Hasan; S.I. Rahayu; I Made Arcana; Cynthia Linaya Radiman
Jurnal Matematika & Sains Vol 10, No 4 (2005)
Publisher : Institut Teknologi Bandung

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Abstract

Copolyesters from ε- caprolactone and 2,2-dimethyl-1,3-propanediol have been synthesized by using distannoxane as catalyst. The influence of monomer compositions on viscosity, melting point and structure of polyesters was studied. The results showed that the increase of ε- caprolactone content in copolymer increased the melting point and viscosity of polyester. This was supported by the decrease of hydroxyl number of polyester when the ε- caprolactone monomers in the copolymers increased.
Pengaruh Variasi Konsentrasi Asam Sulfat pada Proses Hidroksilasi Minyak Jarak (Castor Oil) Marlina Marlina; N. M. Surdia; Cythia Linaya Radiman; S. Achmad
Jurnal Matematika & Sains Vol 9, No 2 (2004)
Publisher : Institut Teknologi Bandung

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Abstract

Castor oil is derived from the bean of castor plant Ricinus communis L., belonging to Euphorbiaceae family from Nangroe Aceh Darussalam. Oil rendement per gram of castor bean is 45 – 52% with high purity and better than the standard oil given by AOAC. Acetylation and methylation protective process occurs on hydroxyl group of castor oil, indicated by decreasing of hydroxyl number, and also changing the structure of oil. Hydration process is more efective on acetylation-protective oil than that on non-protective and methylation-protective oil. Optimum condition reached when acid (H2SO4) concentration was 5% for non protective, 20% for acetylation protective and 15% for methylation protective oil. At those conditions, iodine and hidroxy values for non-protective, acetylation-protective, and methylation protective oil were 56.0 and 730.3; 23.3 and 664.5; and 38.5 and 649.8 mg/g, respectively.
Pengaruh Temperatur terhadap Mekanisme Inhibisi oleh Sistein pada Korosi Baja Karbon dalam Larutan NaCl Jenuh CO2 Yayan Sunarya; Cynthia Linaya Radiman; Sadijah Achmad; Bunbun Bundjali
Jurnal Matematika & Sains Vol 13, No 3 (2008)
Publisher : Institut Teknologi Bandung

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Abstract

The inhibition mechanism of cysteine on API 5L X65 carbon steel corrosion in CO2-saturated NaCl solution at 300K –360K was studied. The investigations involved potentiodynamic polarization, electrochemical impedance spectroscopy(EIS) methods and computer simulation of Zview program. The results showed that the inhibition mechanism takes placethrough formation of passive layers that covers carbon steel surface with inhibition efficiency up to 85%. Functionalgroup dominantly involved in the formation process of the passive layers is –SH at low temperature, and –NH3+ athigh temperature. The increasing temperature alters the carbon steel corrosion/inhibition process from kinetics ofcharge transfer to diffusion process.
DEPOSISI NANOPARTIKEL PLATINUM DALAM MEMBRAN NATA DE COCO SECARA IN SITU Cynthia Linaya Radiman, Djulia Onggo, Intan Syahbanu,
SEMIRATA 2015 Prosiding Bidang Kimia
Publisher : SEMIRATA 2015

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (335.86 KB)

Abstract

Platinum (Pt) merupakan salah satu material dengan aplikasi yang luas.  Efektifitas platinum dapat ditingkatkan melalui desain ukuran partikel hingga berada dalam orde 1-100 nm. Nanopartikel platinum telah berhasil dideposisikan pada matriks nata de coco secara in situ menggunakan larutan prekursor kalium tetrakloroplatinat (K2PtCl4) dengan metode sonikasi.  Komposit Pt/nata de coco diperoleh setelah melalui tahapan reduksi oleh natrium borohidrida (NaBH4) dan gas hidrogen.  Konsentrasi larutan prekursor yang digunakan adalah 2 mM, 5 mM dan 10 mM.  Hasil penelitian dianalisis dengan SEM-EDS menunjukkan nanopartikel Pt telah berhasil dideposisi dengan  % berat unsur Pt di dalam nata de coco untuk masing-masing konsentrasi prekursor adalah 1,96%, 3,17% dan 5,46%.  Analisis dengan Spektrofotometer UV-Visible menunjukkan massa Pt yang terdeposisi di dalam matriks nata de coco  berturut-turut adalah 22,6 mg/cm2, 66,4 mg/cm2, 146,3 mg/cm2.  Ukuran rata-rata partikel yang terdeposisi pada matriks nata de coco adalah 40 nm. Penelitian dan pengembangan lebih lanjut masih perlu dilakukan untuk mengoptimalkan komposit Pt/nata de coco yang dihasilkan. Katakunci: nata de coco, kalium tetrakloroplatinat, nanopartikel platinum
KARAKTERISASI SELULOSA MIKROBIAL YANG DIMODIFIKASI DENGAN TEKNIK KOPOLIMERISASI CANGKOK Tita Puspitasari; Cynthia Linaya Radiman
Jurnal Sains Materi Indonesia Vol 9, No 3: JUNI 2008
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (309.713 KB) | DOI: 10.17146/jsmi.2008.9.3.4689

Abstract

KARAKTERISASI SELULOSA MIKROBIAL YANG DIMODIFIKASI DENGAN TEKNIK KOPOLIMERISASI CANGKOK. Modifikasi kimia dan fisika polimer dapat dilakukan dengan kopolimerisasi cangkok yang diinisiasi dengan radiasi. Penelitian ini dilakukan untuk mempelajari morfologi dan kristalinitas kopolimer selulosa mikrobial yang dicangkok dengan asam akrilat (SM-g-AAc). Analisis struktur mikro SEM membuktikan bahwa asam akrilat mampu berdifusi ke dalam lapisan selulosa mikrobial dan mengakibatkan struktur porinya menjadi lebih rapat. Pengukuran kristalinitas menunjukkan bahwa kristalinitas selulosa mikrobial setelah dimodifikasi naik dari 50% menjadi 53%.
PEMBUATAN SELULOSA ASETAT DARI PULP KENAF (Hibiscus cannabinus) Senny Widyaningsih; Cynthia Linaya Radiman
Molekul Vol 2, No 1 (2007)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (96.378 KB) | DOI: 10.20884/1.jm.2007.2.1.181

Abstract

Cellulose acetate (CA) is one of polymer which is usually used in industry. Kenaf (Hibiscus cannabinus) pulp is one of non wood cellulose sources which can be used for producing CA. CA was produced in three step i.e. initial, acetylation, and hydrolysis. The characterization of CA kenaf had been conducted with analyzing function groups and determining relative molecule mass, acetyl content, and structure of CA. The result of infrared spectroscopy analyze showed that specific peak of acetyl group at 1237.4 cm-1 with acetyl content 40.40% and the relative molecule mass of CA was 1.15.104 with amorf structure.
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.
Ab Initio Study of Proton Transfer and Hydration in Phosphorylated Nata de Coco Sitti Rahmawati; Cynthia Linaya Radiman; Muhamad Abdulkadir Martoprawiro
Indonesian Journal of Chemistry Vol 17, No 3 (2017)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (507.986 KB) | DOI: 10.22146/ijc.24895

Abstract

This research aims to calculate energetics parameters, hydrogen bonding, characteristics local hydration, and proton transfer in phosphorylated nata de coco (NDCF) membrane using ab initio method. The minimum energy structure of NDCF membranes and the addition of n water molecules (n = 1-10) determined at the B3LYP/6-311G** level indicates that proton dissociation requires a minimum of four water molecules. Dissociated protons stabilize with the formation of (hydronium, Zundel, Eigen) ions. Calculation of the interaction energy with n water molecules indicates an increasingly negative change in energy (ΔE) and enthalpy (ΔH), and hence an increasingly positive interaction with water molecules. This interaction facilitates the transfer of protons in the membrane matrix. Calculation of the rotational energy at the center of C-O indicates that the pyranose ring structure, with a maximum barrier energies of ~ 12.5 J/mol, is much more flexible than the aromatic backbones of sulfonated poly(phenylene) sulfone (sPSO2) and the polytetrafluoroethylene (PTFE) backbones in perfluorosulfonic acid ionomers (PFSA). These energy calculations provide the basis that the flexibility of the pyranose ring and the hydrogen bonding between water molecules and phosphonate groups influence the transfer of protons in the membrane of NDCF.
Density Functional Theory (DFT) and Natural Bond Orbital (NBO) Analysis of Intermolecular Hydrogen Bond Interaction in "Phosphorylated Nata De Coco - Water" Sitti Rahmawati; Cynthia Linaya Radiman; Muhamad Abdulkadir Martoprawiro
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (502.91 KB) | DOI: 10.22146/ijc.25170

Abstract

This study aims to study the conformation, the hydrogen bond network, and the stabilities of all the possible intermolecular interactions in phosphorylated nata de coco membrane with water (NDCF-(H2O)n, n = 1-5). Analysis of natural bond orbital (NBO) was performed to measure the relative strength of the hydrogen bonding interactions, charge transfer, particularly the interactions of n-σ * O-H and to take into account the effect on the stabilities of the molecular structure. All calculation were performed using density functional theory (DFT) method, at B3LYP functional level of theory and 6-311 G** basis set. The charge transfer between the lone pair of a proton acceptor to the anti-bonding orbital of the proton donor provides the substantial to the stabilization of the hydrogen bonds. Interaction between NDCF and (H2O)5 was strongest with the stabilization energy of 37.73 kcal/mol, that indicate the ease of donating lone pair electrons. The contributions of each hydrogen bond to the stability of the complex have been analyzed.
Pengaruh Konsentrasi Agen Pensulfonasi Terhadap Karakteristik Membran Selulosa Bakterial Tersulfonasi Pada Aplikasi DMFC Nayla, Mahdiya; Radiman, Cynthia Linaya
ALCHEMY:Journal of Chemistry Vol 10, No 2 (2022): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18860/al.v10i2.13519

Abstract

Penelitian ini bertujuan mengetahui pengaruh konsentrasi agen pensulfonasi asam klorosulfonat pada membran selulosa bakterial untuk aplikasi DMFC (Direct Methanol Fuel Cell). Konsentrasi asam klorosulfonat yang digunakan 0,5-3% dengan sulfonasi menggunakan metode MAOS (Microwave Assisted Organic Synthesis). Karakterisasi membran meliputi analisis gugus fungsi dengan FTIR, swelling, konduktivitas proton, kapasitas penukar ion, SEM (Scanning Electron Microscopy) dan penentuan kadar sulfur dengan EDS (Electron Dispersive X-Ray Spectroscopy). Hasil analisis FTIR menunjukkan munculnya puncak pada bilangan gelombang 1163 cm-1 yang menunjukkan vibrasi asimetris S=O pada sulfonat. Uji penggembungan membran menunjukkan bahwa derajat penggembungan mengalami kenaikan sebanding dengan persentase kadar asam klorosulfonat. Nilai konduktivitas dan kapasitas penukar ion membran selulosa bakterial tersulfonasi juga meningkat seperti derajat swelling. Foto permukaan membran dengan SEM menunjukkan morfologi serat membran selulosa bakterial. Kadar sulfur pada permukaan membran selulosa bakterial tersulfonasi semakin besar seiring dengan indohoki77 bekerja sama dengan penyedia perangkat lunak terkemuka di industri untuk memastikan kualitas permainan yang tinggi. Grafik yang tajam, suara yang jernih, dan animasi yang menarik menambah keseruan bermain di platform ini bertambahnya persentase asam klorosulfonat. Hal ini menunjukkan semakin banyaknya gugus –OH yang tersubstitusi dengan –SO3H pada membran selulosa bakterial tersebut. Sulfonasi membran selulosa bakterial paling baik dengan asam klorosulfonat 3% menghasilkan karakteristik derajat penggembungan 183,54%, konduktivitas 0,052 S/cm, kapasitas penukar ion 3,88 meq/g serta persentase kadar sulfur 0,94%.
Co-Authors Ari Handono Ramelan Bunbun Bundjali Deana Wahyunigrum Deana Wahyuningrum Dian Maruto Widjonarko Edi Pramono Hermawan K. Dipojono I Made Arcana I MADE SUDARMA Khusna Widhyahrini M. Hasan Made Ganesh Darmayanti Marlina Marlina Muhamad Abdulkadir Martoprawiro Muhamad Abdulkadir Martoprawiro Muhamad Abdulkadir Martoprawiro N. M. Surdia Nayla, Mahdiya Nurrahmi Handayani Ozi Adi Saputra RAHMAT GUNAWAN Rosid Eka Mustofa S. Achmad S.I. Rahayu Sadijah Achmad Santi Nurbaiti Sayekti Wahyuningsih Senny Widyaningsih Sentot Budi Rahardjo Sitti Rahmawati Teguh Endah Saraswati Tita Puspitasari Witri Wahyu Lestari Yayan Sunarya Yulianto Adi Nugroho