Biomass, such as wood waste, is one of the resources that can be potentially converted into a carbon product for catalyst applications. In this study, the sulfonated carbon was obtained through the pyrolysis method for wood waste at the temperature of 350°C, which was later sulfonated through the use of H2SO4 (8N) on the reflux for 4 h. The sulfonated carbon was then analyzed and characterized including its water content, ash content, volatile matter, fixed carbon, iodine adsorption as well as the H+ (acidity) capacity using ammonia adsorptions and functional groups and the Fourier Transform Infra-Red (FTIR) instrument. The catalyst application was carried out during the kempili pulp hydrolysis process using a microwave with the ratio of catalyst to a pulp of 1:1 (5g:5g), with the power conditions of 300, 400, and 600 watt for 3, 5, and 7 min. The results showed that the sulfonated carbon catalyst had water content, volatile matter, ash content, fixed carbon, iodine adsorption as well as the catalyst acidity as much as 3.48%; 11.70%; 4.21%; 84.62%; 690.88 mg/g; and 6.45 mmol/g, respectively with the highest glucose content of 160.83 ppm. The carbon-based catalyst is expected as an alternative catalyst, can be further developed for hydrolysis reactions, and can serve as a green technology product in the future.
Silica gel (SG) is one of common adsorbent on solid phase extraction for preconcentration. Due to the low selectivity and effectiveness of adsorption to metal ions, SG should be modified. The SG was modified with d-glycine (Si-Gly) using 3-aminopropyltrimethoxysilane and glutaraldehyde as a crosslinker. Capability of Si-Gly as adsorbent for cadmium ions (Cd) was investigated using batch adsorption. The result was proved by infrared spectra. The optimum condition of Cd adsorption by the Si-Gly was obtained at pH 5, with 0.3 g of adsorbent and 11 minutes of contact time. The percentage of Cd adsorption at the optimum condition by the Si-Gly (99.34%) which is greater than the SG (89.03%). The maximum adsorption capacity of the Si-Gly is 9.77 mg/g, obtained at 400 mg/L. The Cd(II) adsorption on the SG and the Si-Gly follow the Langmuir isotherm equation.
Faktis cokelat merupakan salah satu bahan kimia karet terpenting yang berfungsi sebagai bahan bantu olah kompon karet. Mutu faktis cokelat dipengaruhi oleh pemilihan jenis minyak nabati sebagai bahan baku utama, konsentrasi sulfur, dan suhu reaksi. Reaksi vulkanisasi antara minyak nabati dengan sulfur pada pembentukan faktis cokelat umumnya dilakukan pada suhu 140-190oC. Minyak nabati harus memiliki bilangan iod yang tinggi minimal 80-110 g iod/100 g minyak. Pada penelitian ini dipelajari peluang pembuatan faktis cokelat dari kombinasi minyak jarak kastor dengan minyak nabati lain golongan semi pengering (sawit, jarak pagar) dan pengering (kedelai, jagung, kanola) pada rasio minyak sebesar 80 : 20 dengan penambahan 24 bsm sulfur dan 150oC. Hasil percobaan menunjukkan bahwa faktis cokelat dapat disintesis dari kombinasi antar minyak nabati tersebut pada kondisi reaksi vulkanisasi yang telah ditetapkan. Berdasarkan hasil karakterisasi diperoleh faktis cokelat dengan tingkatan mutu setara dengan faktis cokelat komersial kelas 3. Kombinasi minyak nabati yang menghasilkan faktis cokelat terbaik diperoleh dari campuran antara minyak jarak kastor dengan minyak sawit. Diterima : 14 April 2014; Direvisi : 20 Mei 2014; Disetujui : 12 Juli 2014 How to Cite : Puspitasari, S., Cifriadi, A., Nurgilis, E. L., & Arif, Z. (2014). Sintesis bahan olah kompon karet secara reaksi vulkanisasi dari perpaduan minyak nabati semi pengering dan pengering. Jurnal Penelitian Karet, 32(2), 189-197. Retrieved from http://ejournal.puslitkaret.co.id/index.php/jpk/article/view/164
Phyllanthus niruri is known as a stone breaker and has some biological activities such as antioxidant, antibacterial, anti-inflammatory, antiviral, immunostimulant, etc. There are two other species related to P. niruri namely P. debilis and P. urinaria. The morphology of the three plants is quite similar so that identification and discrimination of the three species are very crucial to avoid adulteration of P. niruri from the two related species for ensuring the quality, efficacy, authenticity, and safety of its herbal medicinal product. This study aims to develop identification and discrimination method of P. niruri based on thin-layer chromatographic (TLC) fingerprint combined with chemometrics analysis. The result showed that P. niruriprovides a different fingerprint profile compare to P. debilis and P. urinaria. P. niruri has two characteristic bands (Rf 0.71 and 0.77) that could be used for discrimination from P. debilis and P. urinaria. To enhance the discrimination of the three species, we used discriminant analysis with peak area from 13 detected peaks as the variable. From the results obtained, the discriminant analysis showed the separation of each species using the first two discriminant function (DF) with variance for DF-1 = 63.34% and DF-2 = 36.66% in DA plots, which explain 100% of total discriminant factor varianceand correct classification rate is 100%. The developed TLC fingerprint combined with discriminant analysis successfully distinguished three closely related species of Phyllanthus.
Orthosiphon aristatus, known as kumis kucing in Indonesia, has some biological activity, i.e., as an anti-inflammatory, fever, rheumatism, diabetes, and kidney stone. This plant is also known for being rich in phenolic compounds such as flavonoids. In this study, we would like to compare the antioxidant activity, total phenolics, and flavonoid content from the stems and leaves of Orthosiphon aristatus extracted with water and ethanol by maceration. The yield stem and leaves of the water extract are 12.98-31.28%, and ethanol extract 3.58 - 9.82% (dry basis). The stem and leaves water extract contains a phenolic of 7.82-26.43 (mg GAE/g) and ethanol extract of 2.27-7.84 (mg GAE/g). Water extract Orthosiphon aristatus flavonoid content is 1.23-2.86 (mg EK/g), and ethanol extract is 1.09-3.95 (mg EK/g). The antioxidant activity of ethanol (IC50), extract from leaves was 123.91 (µg/mL) and from stems was 125.50 (µg/mL), while IC50 of water extract from leaves was 114.70 (µg/mL) and from stems was 125.03 (µg/mL). The correlation test result of active compounds using linear regression is phenolic compounds with antioxidants stronger than flavonoids. The qualitative thin-layer chromatography fingerprint analysis showed that ethanol and water extract contained natural sinensetin compounds.
ABSTRAKManufaktur produk karet diawali oleh pembuatan kompon karet dengan cara mencampurkan karet dengan bahan kimia. Salah satu bahan kimia utama karet adalah bahan bantu olah yang berfungsi untuk mempermudah pencampuran dan distribusi bahan kimia terutama bahan pengisi dalam matriks karet. Faktis cokelat yang dihasilkan dari vulkanisasi minyak nabati dengan sulfur merupakan bahan bantu olah karet yang banyak digunakan dalam industri hilir karet. Dalam reaksi vulkanisasi terjadi pembentukan ikatan silang antar trigliserida dalam minyak nabati yang dijembatani oleh sulfur. Penelitian ini bertujuan untuk menen-tukan kondisi optimum pembentukan faktis cokelat pada skala laboratorium berkapasitas 200 ml/batch dari minyak jarak kepyar sebagai sumber trigliserida yang direaksikan dengan sulfur (23 dan 24 bsm) pada berbagai suhu ABSTRACTManufacture of rubber goods is began with rubber compounding by mixing the rubber with its chemicals including processing aids. The function of processing aids is to facilitate the compounding process. Brown factice from vulcanization of vegetable oil with sulphur, is the most processing aid being used in downstream rubber industry. During vulcanization, the triglyceride content on vegetable oil form crosslink which is bridged by sulphur. The research was aimed to determine the optimum condition of brown factice formation at laboratory scale (200 ml/batch) from castor oil which was reacted with various sulphur concentration (23 and 24 pho) and themperature of reaction ( C and sulphur concentration of 24 pho. By those condition, the brown factice had 52.43% extract acetone content, 1.20% free sulphur content, 0.11% ash content and pH 6.45 and crosslink density as 3.2 x 10 -4 mol/ml. The brown factice also had good brown color and elastic texture. Based on its properties, the brown factice achieved was feasible to be developed at higher scale.
The construction and performance of ion selective electrodes (ISEs) for the determination of chromium(VI) based on PVC membranes modified with 1,5-diphenylcarbazide (DPC) and natural zeolite as ionophores are reported in this study. ISE was fabricated in an optimum composition of chromium(VI)-selective membrane consisting of 29 mol% DPC, 43.6 mol% natural zeolite, 25 mol% plasticizer, and 2.2 mol% PVC. The investigation of the performance of the proposed ISE was evaluated in terms of the Nernstian response, range of concentration, limit of detection, response time, and selectivity coefficient. The proposed ISE displayed a linear potential response over a concentration range of 10 −1 -10 −6 M K 2 Cr 2 O 7 with a Nernstian response of −28.8 mV/decade. Adequate sensitivity for chromium(VI) was offered by the proposed ISE with a limit of detection of 2.14×10 −6 M and a response time of ∼250 s. The fabricated ISE has also been investigated in selectivity studies in the presence of Cu 2+ and Fe 3+ and was found to be more selective in the concentration range of 10 −1 -10 −6 M. Therefore, a novel membrane electrode using a composite of DPC and natural zeolite as an ionophore has shown a satisfactory result for the direct potentiometric measurement of chromium(VI) in the presence of Cu 2+ and Fe 3+ , which may have the potential to be used in real sample analysis.
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