Claim Missing Document
Check
Articles

Found 22 Documents
Search

POLY FRACTION (TRIMETILEN-BASED) FROM MONOMER RENEWABLE ONLY SOLUTION AND DECREASE TEMPERATURE Diah Mardiana; Bambang Poerwadi; Budi Kamulyan; Siannita Chandra
Jurnal Penelitian Saintek Vol 19, No 1: April 2014
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (836.151 KB) | DOI: 10.21831/jps.v19i1.2327

Abstract

Poly(trimethylene-sebacate), polyester material from glycerol and castor oil monomer resources, have been synthesized. Fractionation using suitable solvent-non solvent composition could be produced the pure polymer. In this experiment dissolution methods were modified by reduced temperature. In order to choose the suitable solvent and its composition, it was monitored by the turbidity, while the effect of reduced temperature were analysed based on poly(trimethylene-sebacate) mass and several physical properties of product. Result showed that the suitable solvent and non solvent were chloroform and methanol, respectively. As with out reduced temperature, the volume composition was 1 : 10, while temperature modified could be reduced 50% of methanol used. Furthermore, concentration of poly(trimethylene-sebacate) of 3% using volume composition of 1 : 5 at temperature of 20-22 oC , it was yielded 48.4% of product. It has melting point of 52 C with intrinsic viscosity of 10.89 mL/g, Mn 2632 g/eq and degree of crystalinity was 30.5%.  
MODIFICATION OF SCREEN PRINTED CARBON ELECTRODEBY POLYPYRROLE FOR DETERMINATION OF HYDROQUINONE Khoirul Ngibad; Ani Mulyasuryani; Diah Mardiana
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.12.1.938.36-49

Abstract

Electropolymerization of polypyrrole for determination of hydroquinone on screen printed carbon electrode (SPCE) was performed using cyclic voltammetry. Electropolymerization of polypyrrole on SPCE begins with determining the optimum conditions of cyclic voltammetry (working potential, scan rate, number of cycles) and the conditions of solution (pyrrole and KCl concentrations).The working potential were varied at 0 – 0.8; 0 – 0.9; 0 – 1 V. The variation of scan rate were 50, 100, 150 mV/s and number of cycleswere 5, 10,15 cycles. The influence of pyrrole concentration was studied by providing variation of 5, 50, 100 mM. Meanwhile, the KCl concentration were at 0.1; 0.5; 1 M. The SPCE modified with polypyrrole was washed with deionized water and was dried at room temperature. The prepared polypyrrole was analyzed and based on the high anodic and cathodic peak current of the hydroquinone, it is confirmed that the preparation was succefully conducted. The optimum conditions on electropolymerization of polypyrrole areat the working potential of 0 – 0.9 V; the scan rate 100 of mV/s; the number of cyclesis 10, and at thepyrroleconcentration of 50 mM and KCl concentration of 0.5 M. SPCE modified polypyrrole can determine the hydroquinone at the concentration range of 5 – 100 μM with the sensitivity of 0.120 μA/Μm and the detection limit (S/N = 3) of 0.8 μM.
ISOLASI SELULOSA DARI JERAMI PADI MENGGUNAKAN VARIASI KONSENTRASI BASA Dewi Umaningrum; Radna Nurmasari; Maria Dewi Astuti; Mardhatillah Mardhatillah; Ani Mulyasuryani; Diah Mardiana
Jurnal Sains dan Terapan Kimia Vol 12, No 1 (2018)
Publisher : Program Studi Kimia, Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (637.665 KB) | DOI: 10.20527/jstk.v12i1.4652

Abstract

Telah dilakukan penelitian tentang isolasi selulosa dari jerami padi menggunakan variasi konsentrasi basa. Pada penelitian ini dipelajari tentang pengaruh basa dan variasi konsentrasinya dalam isolasi selulosa dari jerami padi. Kajian pengaruh basa dan konsentrasi dilakukan dengan melarutkan ekstrak jerami padi pada NaOH dan KOH dengan variasi konsentrasi 1%, 3%, 5%, 7% dan 9% dan kemudian dilakukan analisis IR terhadap selulosa hasil isolasi serta dihitung rendemen selulosa dan lignin sisa. Hasil penelitian menunjukkan bahwa pada isolasi selulosa dari jerami padi digunakan NaOH 7% dengan rendemen selulosa yang diperoleh sebesar 33,63% dengan lignin sisa sebesar 2,42%.Kata kunci : isolasi, selulosa, lignin sisa
Structure and Dynamics of Curcumin Encapsulated Lecithin Micelles: A Molecular Dynamics Simulation Study Lukman Hakim; Diah Mardiana; Urnik Rokhiyah; Maria Lucia Ardhani Dwi Lestari; Zubaidah Ningsih
Science and Technology Indonesia Vol. 6 No. 3 (2021): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2024.157 KB) | DOI: 10.26554/sti.2021.6.3.113-120

Abstract

Curcumin is a natural product with potential pharmaceutical applications that can be augmented by drug delivery technology such as nano emulsion. Our study focuses on microscopic structural and dynamics response of curcumin encapsulation in micellar system with lecithin as a natural surfactant under variations of composition and temperature using molecular dynamics (MD) simulations. The results highlight the self-assembly of lecithin micelle, with curcumin encapsulated inside, from initial random configurations in the absence of external field. The variation of composition shows that lecithin can aggregate into spherical and rod-like micelle with the second critical micelle concentration lies between 0.17-0.22 mol dm−3. The radial local density centering at the micelle center of mass shows that the effective radius of micelle is indeed defined by the hydrophilic groups of lecithin molecule and theencapsulated curcumin molecules are positioned closer to these hydrophilic groups than the innermost part of the micelle. The spherical micelle is shown to be thermally stable within the temperature range of 277-310 K without a perceivable change in the spherical eccentricity. The dynamics of micelle are enhanced by the temperature, but it is shown to be insensitive to the variation of lecithin-curcumin composition within the studied range. Simulation results are in agreement with the pattern obtained from experimental results based on particle size, polydispersity index, and encapsulation efficiency.
Comparison of Fabrication Technique and Carrier Oil to Curcumin Nanoemulsion Properties Zubaidah Ningsih; Sepriana Puspita Dewi Syaiful; Maria L.A.D Lestari; Diah Mardiana; Budi Kamulyan
The Journal of Pure and Applied Chemistry Research Vol 12, No 1 (2023): Edition January-April 2023
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jpacr.2023.012.01.701

Abstract

Turmeric (Curcuma longa L.) is included in the rhizome plant containing curcumin which has various therapeutic properties. However, curcumin has poor bioavailability. The manufacture of nanoemulsion is expected to increase curcumin bioavailability. This study aims to compare 3 methods (wet-ball milling, ultrasonication and microfluidic) and 3 carrier oils (soybean, virgin coconut, and olive oil) in the production of curcumin nanoemulsion. Wet-ball milling reduces particle size through grinding process using milling beads in liquid medium. Microfluidic decreases the particle size via collision of emulsion components in microchannel while ultrasound utilizes sound-wave energy to break down the particle size. Parameters compared were particle size, polydispersity index and entrapment efficiency. Particle size and polydispersity index were observed using Particle Size Analyzer with Dynamic Light Scattering technique while entrapment efficiency was measured based on the curcumin absorbance in UV-Visible spectrophotometer at 420 nm. Our study concludes that microfluidic is the most effective and efficient fabrication method which produces the smallest particle size and polydispersity index compared to ultrasonication and microfluidic. The resulting particle sizes using microfluidic are 154, 140 and 132 nm with polydispersity index of 0.224; 0.200and 0.208 insoybean,virgin coconut, and oliveoil respectively. However, entrapment efficiency is best achieved using wet-ball milling method with the average value of 49±10%. Soybean oil appears to be the most curcumin solubilizing oil compared to olive and virgin coconut oil. Thus, it can be concluded that fabrication methods and carrier oils determine curcumin nanoemulsion properties.
Okra Mucilage Extract as A Co-Surfactant Increased the Curcumin Nanoemulsion Stability and Encapsulation Efficiency El Fajriyah Aulia Putri; Ellya Indahyanti; Diah Mardiana; Maria Lucia A.D Lestari; Zubaidah Ningsih
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.3.509-515

Abstract

Curcumin has various bio-functional properties; however, curcumin poor bioavailability reduces its efficacy. Nanoemulsion delivery system is an alternative method improving curcumin bioavailability in which surfactant and oil used, play an important role in determining nanoemulsion properties. Several studies on curcumin nanoemulsions apply synthetic surfactants which can be harmful if they are added excessively. This study aims to use a natural emulsifying agent, namely okra mucilage extract (OME), and determine its effectiveness as co surfactant. OME is safe to use as an emulsifying agent because it is natural, harmless, safe, biodegradable and eco-friendly. Liquid-liquid and microwave extraction methods were used to obtain OME which was further identified using Fourier Transfer Infrared Spectroscopy (FTIR). Meanwhile, sonication method was used to produce curcumin nano-emulsion (CurN). The particle size and polydispersity index of curcumin nano-emulsion were measured using Particle Size Analyzer (PSA) with Dynamic Light Scattering (DLS) technique, while the morphology of the nanoemulsion was observed using a Digital Imaging Microscope and Confocal Laser Scanning Microscope (CLSM). The results showed that the addition of 0.0160 g OME at a ratio of 1:5 (OME: Tween 80) in the preparation of 5 mL of CurN was able to reduce the particle size and polydispersity index from 740.80 ± 9.70 nm to 289.20 ± 2.23 and 0.340 ± 0.005 to 0.165 ± 0.008 respectively. OME increased the encapsulation efficiency from 77.93 ± 6.59% to 87.17 ± 1.12% which was confirmed by the augmentation of the fluorescence intensity of curcumin from 192.82 to 388.55. The addition of OME also maintained the stability of the CurN up to 14 days of storage at 4°C.
Effects of Preparation Temperature and Liquid-Solid Lipid Composition to Curcumin-Nanostructured Lipid Carrier Characteristics Fabricated by Microfluidic Technique Ridho Arief Al Rasyid; Diah Mardiana; Ridho Firmansyah; Zubaidah Ningsih
The Journal of Pure and Applied Chemistry Research Vol 12, No 2 (2023): May-August 2023
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jpacr.2023.012.02.3317

Abstract

Nanostructured Lipid Carriers (NLC) are lipid-based carrier that uses a combination of liquid and solid lipids which is believed to deliver a higher amount of active substance to the human body. This study aimed to obtain the best formulation and evaluate the stability of curcumin-loaded NLC (C-NLC) using microfluidic technique at temperature of 40oC and 60oC with the ratios of liquid:solid lipids were 2 : 1 ; 3.5 : 1 ; 4 : 1 ; 6 : 1% w/w. Our results showed that the increase of process temperature and liquid lipid concentration reduced particle size. There was a non-linear relationship between lipid ratio and temperature to encapsulation percentage. At ratio of soybean oil:stearic acid 6 : 1 and, at 40°C, particles size (PS) obtained was 143.87 ± 3.36 nm, polydispersity index (PDI) obtained was 0.44 ± 0.01, zeta potential (ZP) obtained was -33.3 ± 6.53 mV with encapsulation percentage of 20.62%. At the same ratio at 60°C, the PS obtained was 60.21 ± 2.55 nm, PDI obtained was 0.72 ± 0.03, ZP obtained was -26.10 ± 1.83 mV and encapsulation percentage of 31.45%. Stability test showed that C-NLC produced at 60°C was more stable since the change of particle size and pH were lower than C-NLC produced at 40°C.
In situ Measurement of Phosphate using Fe3O4/Chelex®100-Agarose-Oxalic Acid Hydrogel in Diffusive Gradient in Thin Films Dinira, Layta; Rumhayati, Barlah; Mardiana, Diah; Andayani, Ulfa
Molekul Vol 19 No 2 (2024)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2024.19.2.11199

Abstract

ABSTRACT. This study would be the first to develop a novel combination of Chelex®100 and Fe3O4 as a mixed binding gel for in situ phosphate measurement employing Diffusive Gradient in Thin Films (DGT). Fe3O4 and Chelex®100 were utilized as binding agents within a single binding layer for phosphate measurements in laboratory and natural water settings. The synthesized Fe3O4 was identified as magnetite and consisted of micro-sized particles. The pore size of the mixed binding gel ranged from 22.39 to 112.5 µm. Incorporating Chelex®100 with Fe3O4 in oxalic acid cross-linked agarose did not diminish phosphate adsorption efficiency. As adsorption time and phosphate concentration in solution increased, the quantity of adsorbed phosphate in the mixed binding gel also increased. Optimal phosphate elution was achieved using a basic solution, with a phosphate elution efficiency of 95.3 ± 0.4% observed with 0.4 M NaOH. The diffusion coefficient measured using the mixed binding gel was 1.08 times greater than that of polyacrylamide cross-linked with an agarose derivative (APA) gel, typically employed in the DGT technique. Phosphate concentration measurement with Fe3O4/Chelex®100-agarose oxalic acid in a DGT passive sampler at pH 4-8 yielded values twice those in bulk solution. Similar results were obtained when measuring phosphate in a 0.01 – 0.1 M NaNO3 solution. A T-test showed that the phosphate concentration obtained from mixed binding layer-DGT as an alternate passive sampler was not significantly different from grab sampling. This study underscores the suitability of Fe3O4-Chelex®100 impregnated in agarose-oxalic acid gel for monitoring phosphate in natural water via DGT. Keywords: Agarose, diffusive gradient in thin films, mixed binding gel Fe3O4, oxalic acid.
Variation of Iodine Mass and Acetylation Time On Cellulose Acetate Synthesis From Rice Straw Umaningrum, Dewi; Astuti, Maria Dewi; Nurmasari, Radna; Hasanuddin, Hasanuddin; Mulyasuryani, Ani; Mardiana, Diah
Indonesian Journal of Chemical Research Vol 8 No 3 (2021): Edition for January 2021
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2021.8-dew

Abstract

Cellulose acetate is a membrane material that can be used in the sensor field. One source of cellulose acetate is from rice straw. This study aimed to study the effect of iodine mass and acetylation time on cellulose acetate synthesis from rice straw. The initial step is to isolate cellulose from rice straw, followed by cellulose acetate synthesis using iodine catalyst by varying the amount of iodine as much as 0.1-0.3 grams and acetylation time for 1 until 5 hours. The cellulose acetate was characterized using an infrared spectrophotometer, and its viscosity was determined. The result shows that the cellulose 33.63%. The maximum time of cellulose acetate acetylation is 2 hours with a mass of iodine 0.2 g. The yield of cellulose acetate was 14.98%, with an acetyl value of 19.11% and a degree of substitution of 0.89. The cellulose acetate produced has a low viscosity. The FTIR characterization of cellulose acetate shows O-H functional groups at 3333 cm-1, C-H functional groups at ​​2897 cm-1, carbonyl functional groups at 1722 cm-1 C-O functional groups at 1029 cm-1 that were identical in cellulose acetate compounds. The amount of iodine and the acetylation time affected the cellulose acetate product.
Battery Performance Analysis of Solar Cell Powered Water Purification System: Case Study of Indonesian Army Polytechnic in Batu - East Java Hidayat, Muhammad Iman; Mardiana, Diah; Srihardyastutie, Arie; Komara, Acep Nana
Jurnal Pembangunan dan Alam Lestari Vol. 16 No. 2 (2025): Jurnal Pembangunan dan Alam Lestari
Publisher : Postgraduate School of Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jpal.2025.016.02.07

Abstract

A solar cell-powered water purification system (SC-WPS) was developed and installed to generate clean water using renewable energy at the Polytechnic of the Indonesian Army (POLTEKAD). Developed and implemented using renewable energy from a 100 Wp solar panel, a solar cell-powered water purification system (SC-WPS) was designed to address this issue. The battery performance of the system is the primary focus of this work, encompassing battery discharge, state of charge (SOC), and key electrical parameters such as voltage, current, power, and solar irradiation data. Under test, the solar panel generated up to 495.7 Wh/day with a peak power of 93.28 W. Although the voltage remained between 12.78 V and 12.84 V, the battery depletion process showed stability; the total energy generated increased from 92.2 Wh in the first hour to 766.1 Wh by the tenth hour. Although the solar panel efficiency of the system peaked at 15.2%, factors such as uneven sunshine and energy loss caused it to decline over time. These results underscore the need to maximize battery capacity and solar panel efficiency to ensure continuous system operation for water purification in areas with varying sunshine levels. Keywords: battery performance, clean water, energy efficiency, Solar cell