KOVALEN: Jurnal Riset Kimia
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Pengaruh Konsentrasi Surfaktan Non-Ionik Terhadap Viskositas Perekat Polivinil Asetat Berbasis Air: Effect of Non-Ionic Surfactant on Water-Based Adhesive Viscosity
Get PDFSubstrate combining could be done by using adhesive. In Indonesia, especially industrial field, solvent base adhesives were still being developed. This kind of adhesive was not environmental friendly and not safe handling. Therefore, Polyvinyl Acetate (PVAc) water-based adhesive was prepared as an outcome of this research as one of solution to overcome the problem above. Effect of surfactant concentration on the viscosity was aimed at this research. Semi continuous polymerization with stirring motor rates on 50 – 500 rpm was used (optional). Pressure of 1 atm, 750C temperature, 5 – 6 hours reaction time for each was used as polymerization operation in this research. Vinyl Acetate Monomer (VAM), partial hydrolysis Polyvinyl Alcohol (PVOH), water, Ammonium Persulfate (APS) were prepared as raw material. NP-10 and NP-06 were non-ionic surfactants which each concentration was varied in this research. Water-based adhesive with NP-06 concentration variation resulting in viscosity from 98 m.Pa for 0.17 %wt concentration to 213 m.Pa for 0.68 %wt concentration. While NP-10 concentration variation resulting viscosity from 143 m.Pa for 0.17 %wt to 321 m.Pa for 0.68 %wt concentration. Therefore, adhesive with NP-10 surfactant concentration variable has a higher viscosity rate than NP-06 ones.
Keywords: Water-based adhesive, non-ionic surfactant, adhesive viscosit
Analisis Kadar Serat dan Protein Total Sereal Berbasis Tepung Ampas Kelapa dan Ikan Cakalang (Katsuwonus pelamis): Analysis of Fiber Content and Total Protein of Cereal Based on Coconut Pulp and Skipjack Tuna (Katsuwonus pelamis) Flour
Get PDFResearch on the analysis of fiber and protein on cereal based on coconut pulp and skipjack tuna (Katsuwonus pelamis) flour has been carried out. The purpose of this study was to determine the ratio of coconut pulp flour and skipjack tuna flour which produced the highest fiber content and protein content in cereal processed products and to know the preference level of panelists for cereal processed products. The ratio of coconut pulp and skipjack tuna flour used in this study, namely 25:75, 50:50, 75:25 (w/w), and without the addition of coconut pulp flour and skipjack tuna flour. The results showed that cereal with the highest fiber content was obtained at a ratio of 75:25 i.e. 10.52% and the lowest fiber content was obtained at the cereal without the addition of coconut pulp flour and skipjack tuna flour i.e. 1.19%, whereas the highest protein content of cereal was obtained at a ratio of 25:75 i.e. 26.02% and the lowest protein content was obtained at the cereal without the addition of coconut pulp flour and skipjack tuna flour i.e. 9.17%. The highest preference level (5.57) of the panelists for the cereal flour of coconut pulp and skipjack tuna flour is the 75:25 ratio.
Keywords: Skipjack tuna flour, coconut pulp flour, cereal, fiber, protei
Ekstraksi dan Uji Stabilitas Zat Warna Alami dari Bayam Merah (Alternanthera amoena Voss): Extraction and Stabilization of Natural Dyes from Red Spinach (Alternanthera amoena Voss)
Get PDFResearch on the extraction and stability test of natural dye from red spinach (Alternanthera amoena Voss) has been carried out. This study aims to determine the effect of pH and length of sun exposure on the stability of the dye from red spinach. Extraction using the maceration method with ethanol solvent and measurement using a UV-Vis spectrophotometer. Stability testing is carried out at pH 2-5 and sun exposure for 1-4 hours using a dark and light container. The results obtained, at pH 2 and pH 3, anthocyanins were more stable, compared to pH 4 and 5 which had greater color degradation. In exposure to sunlight, dark containers with a degradation percentage of 31.70% were better than clear containers with a percentage of 48.78%.
Keywords: Anthocyanin, red spinach, natural dyes stability
Konversi Karat Besi Menjadi Besi (III) Sulfat dan Pemanfaatannya Sebagai Adsorpsi Pewarna Tekstil: Iron Rust to Iron (III) Sulphate Conversion and the Utilization as Textile Dye Adsoption
Get PDFIron rust was an iron oxide compound that was less attractive, dirty, brown in color, and could pollute the environment, causing water to turn brown. To minimize iron contamination, conversion was carried out into iron (III) sulfate which was useful as an adsorbent for textile dyes. The purpose of this study was to determine the effect of sulfuric acid concentration and volume of H2O2 10% used to convert iron rust into optimal iron (III) sulfate compounds. The method used was a laboratory experiment on a batch scale and the hydrate content in iron (III) sulfate was carried out by the gravimetric method and its ability as an adsorbent was carried out based on the adsorption of dyes using the spectrophotometric method. The results showed that a reactor filled with 3 grams of iron rust powder and 100 mL of sulfuric acid was stirred at 425 rpm at 80 0C for 30 minutes, added 15 ml 10% H2O2 followed by stirring and heating until the solution was saturated, cooled to form crystals. The crystalline yield in these conditions was the increase in sulfuric acid concentration which resulted in low process efficiency, namely 30.34% at 50% sulfuric acid concentration and 15 mL 10% H2O2. The addition of 10% H2O2 solution to 50 mL of 20% sulfuric acid solution and 3.0 grams of a carat as much as 5 mL-10 mL 10% H2O2 produced iron (III) sulfate with 26.53% process efficiency. Iron (III) sulfate is a white, light gray crystal with the chemical formula Fe2 (SO4)3.5 H2O which was a rhombic shaped crystal. and able to absorb the dye which showed that 1.0 g of iron (III) sulfate was able to absorb the highest amount of red dye in a volume of 100 mL of textile dye solution.
Keywords: Iron rust, synthesis, iron (III), sulfuric acid, textile dye
Aktivitas Antibakteri Ekstrak Metanol dari Kulit Batang Kelor (Moringa oleifera Lam.) Terhadap Bakteri Staphylococcus aureus dan Escherichia coli: Antibacterial Activity of Methanol Extracts from The Stem Bark of Moringa oleifera Lam. Against Staphylococcus aureus and Escherichia coli
Get PDFAntibacterial activity of Moringa oleifera Lam. stem bark has been tested against Staphylococcus aureus and Escherichia coli. The extraction of Moringa oleifera Lam. stem bark was used maceration method with methanol solvent and has obtained extract yield of 6.1%. The antibacterial activity test of Moringa oleifera stem bark extracts used a well diffusion method. The concentration of Moringa oleifera stem bark extract was varied to four concentrations of 1% 2% 3% 4% (w/v). The inhibition zone of methanol extract of Moringa oleifera stem bark against Staphylococcus aureus at extract concentrations of 1%, 2%, 3%, and 4% was 10.08 mm, 11.8 mm, 15.00 mm, and 17.02 mm, respectively. The methanol extract of Moringa oleifera stem bark at concentrations of 1%, 2%, 3%, and 4% could also inhibition of Escherichia coli growth with inhibition zone of 14.01 mm, 16.50 mm, 17.09 mm, and 17.10 mm, respectively.
Keywords: Moringa Oleifera Lam., Antibacterial, Staphylococcus aureus, Escherichia col
Pemisahan Logam Tanah Jarang dari Limbah (Tailing) Emas Poboya dengan Metode Pengendapan: Separation of Rare Earth Metals from Poboya Gold Waste (Tailings) by Deposition Method
Get PDFGold tailings are waste generated from gold mining activities and contain minerals and rare-earth metals (REM) that are much needed in current technological developments. This research was conducted to determine the REM content contained in Poboya gold tailings, through the destruction process using sulfuric acid and precipitation using ammonium hydroxide. The results were showed that the level of REM contained in Poboya gold tailings was 6-7%. REM oxide content analysis performed with Scanning Electron Microscopy - Energy Dispersive X-Ray Spectroscopy (SEM-EDS) obtained 6 types of REM with the main REM levels namely Terbium (Tb): 77-80% dan Lanthanum (La): 13%, as well as other rare-earth metals with smaller amounts of Europium (Eu): 4-5%, Cerium (Ce): 2%, Neodymium (Nd): 0.02% and Gadolinium (Gd): 0.02%. Poboya gold waste can be used by the community as a source of REM and used in various industries.
Keywords: Gold tailings, rare earth metals (REM), destruction, precipitatio
Pengaruh Variasi Konsentrasi NaOH Terhadap Nilai Derajat Deasetilasi Kitosan dari Limbah Cangkang Kerang Hijau (Perna viridis L): The Effect of NaOH Concentration on The Value of The Deacetylation Degree of Chitosan from Green Mussels Shell Waste (Perna viridis L)
Get PDFChitin which is the result of processing from green conch shell waste can be transformed into chitosan through a deacetylation process using variations in the concentration of NaOH. This study aims to determine the optimum conditions of variations in base concentration to the value of the degree of deacetylation of chitosan. The types of bases used are NaOH with the concentration variations of 50%, 55%, and 60%. Chitosan obtained was calculated the yield and characterized using FTIR. The results showed the optimum condition of the value of chitosan deacetylation degree was achieved by using 60% NaOH which produced the highest deacetylation degree value of 76.5%.
Keywords: Green mussels shell, chitin, chitosan, deacetylatio
Pengaruh Kadar Air dan Kadar Asam Lemak Bebas Terhadap Masa Simpan Minyak Kelapa Mandar: The Influence of Water Content and Free Fatty Acid Content on Mandar Coconut Oil Shelf Life
Get PDFMandar coconut oil made in Tulu village, Majene Regency, West of Sulawesi, is very popular among Sulawesi Barat people. It is because of the unique aroma which is not owned by other Mandar oil traders. In addition, according to Mandar coconut oil trader who is also the produsen of Mandar oil said that his coconut oil could be stored for months. This research aimed to know the influence of water content and free fatty acid content on Mandar coconut oil shelf life. Gravimetric Method and Alkaline method were used to determine the water content and the free fatty acid content respectively. The oil was stored at room temperature. Water content and free acid content were measured every week, i.e week zero to week four (5 observations). Shelf life estimation was done by applying the kinetic theory. The result shows that the water content and the free fatty acid content increase as shelf life increases. Mandar coconut oil can be stored at room temperature for 1 month, 12 days.
Keywords: Mandar coconut oil, water content, free fatty acid, shelf lif
Perbandingan Kadar Albumin Ikan Gabus (Channa striata) dari Proses Perebusan dan Pengukusan dengan Menggunakan Uji Biuret: Comparison of Cork Fish (Channa striata) Albumin Content from Boiling and Steaming Process by Using Biuret Test
Get PDFCork Fish (Channa striata) is a freshwater fish that was spread throughout most of Indonesia and it contains albumin that was beneficial to the human body. Albumin was easily dissolved in water during the cooking process both boiled and steamed. This study aims to determine the influence of boiling and steaming times at 100oC against albumin content of cork fish that lost and left in fish meat. The times of boiling and steaming that was used to processing the fish were 10, 15, and 20 minutes. The albumin concentration that lost and left in for the boiling and the steaming process was determined by the biuret test that used a UV-Vis spectrophotometer at albumin maximum wavelength of 530 nm. The results showed that albumin content that lost for 10 minutes boiling process (62 mg/10g) was smaller than the other boiling times and albumin left in fish meat was 164 mg/10g. The same result was also obtained at 10 minutes steaming process which results left in albumin content of 167 mg/10g and lost albumin of 62 mg/10g. The albumin content that lost or dissolved in water for the steaming process was smaller than the boiling process, therefore the steaming process is more efficient than the boiling process at cork fish processing.
Keywords: Cork fish, albumin, boiling, steaming
Skrining Fitokimia, Uji Toksisitas dan Uji Peredaman Radikal DPPH Ekstrak Daun Gelinggang (Cassia alata L): Phytochemical Screening, Toxicity Test and DPPH Radical Scavenging Test of Cassia alata L (Gelinggang) Leaves Extract
Get PDFCassia alata L. (Gelinggang) one of the plants known as medicinal plants, especially for the treatment of skin diseases. The purpose of this study was to determine the type of secondary metabolites using phytochemical tests, toxicity with the BSLT method and antioxidant properties against DPPH radicals from the extract of the Gelinggang leaves. The results of the study showed extracts of Gelinggang leaves containing alkaloids, triterpenoids, steroids, and quinones. Based on the results of toxicity and antioxidant tests showed that Gelinggang leaves extract was very toxic to Artemia salina shrimp and it was a strong antioxidant against DPPH radicals with LC50 and IC50 were 28.84 ppm and 73.57 ppm, respectively.
Keywords: Gelinggang, Cassia alata L., toxicity, antioxidants, DPP