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Abstrak :
ABSTRAK
Carbon nanotube (CNT) memiliki kemampuan untuk memfasilitasi transfer elektron sehingga dapat digunakan sebagai material biosensor yang potensial, khususnya biosensor generasi ketiga. Fabrikasi perangkat bioelektronik sistem transfer elektron langsung ini dilakukan dengan memodifikasi permukaan elektroda emas menggunakan self-assembled monolayer (SAM) dari sistiamina, single wall carbon nanotube (SWCNT) dan mikroperoksidase-11 (MP-11). Metode analisis voltametri siklik dan beberapa karakterisasi lainnya dilakukan untuk mengetahui keberhasilan modifikasi elektroda tersebut sekaligus mengetahui parameter penting dalam aplikasinya sebagai biosensor. Campuran asam kuat H2SO4:HNO3 = 3:1 dibantu ultrasonikator terbukti efektif untuk memotong dan fungsionalisasi SWCNT. Hal ini dibuktikan dengan adanya serapan vibrasi gugus karbonil pada bilangan gelombang 1600 cm-1 pada spektrum FT-IR yang diperoleh. Pembentukan SAM dari sistiamina pada permukaan elektroda emas merupakan dasar modifikasi tahap selanjutnya. Keberhasilan modifikasi ini dapat dilihat dari munculnya puncak katodik pada potensial +390 mV dari kurva voltamogram siklik yang terbentuk. Estimasi nilai pKb sistiamina di atas permukaan elektroda emas sebesar 8,43 ? 0,03 diperoleh berdasarkan teknik elektrokimia. Imobilisasi MP-11 dapat dilakukan melalui pembentukan ikatan kovalen antara gugus amina dari MP-11 dengan gugus karboksilat dari SWCNT yang sebelumnya telah diimobilisasi terlebih dahulu di atas lapisan sistiamina. Pemodifikasian ini dilakukan dengan tujuan terciptanya transfer elektron langsung antara elektroda dan MP-11. Presisi jumlah elektron yang terlibat selama proses reaksi berlangsung adalah sebesar 1,14 x 10-7 ? 0,04 Coulomb. Namun, studi lebih lanjut masih perlu dilakukan agar diperoleh bentuk voltamogram siklik yang reversible serta melakukan karakterisasi lainnya untuk memperkuat bukti keberhasilan fabrikasi elektroda ini. Kata kunci: biosensor generasi tiga; carbon nanotube; mikroperoksidase-11; self-assembled monolayer; sistiamina; voltametri siklik.

Abstrak :
Kebutuhan akan penggunaan carbon nanotube (CNT) dalam negeri terus meningkat setiap tahunnya. Sampai saat ini, produksi dan komersialisasi CNT terkendala pada proses yang mahal. Bahan baku CNT yang berpotensi karena harganya lebih murah adalah liquified petroleum gas (LPG). Untuk merealisasikan produksi CNT di Indonesia, diperlukan analisis tekno ekonomi produksi CNT dari LPG. Produksi CNT dilakukan dengan metode chemical vapor deposition (CVD) menggunakan katalis Fe-Co-Mo/MgO. Produksi dilakukan dalam reaktor fluidized bed yang dilengkapi cyclone untuk memisahkan CNT dengan gas sisa. Sintesis CNT dalam reaktor berlangsung pada suhu 900oC dan tekanan 1 atm. Purifikasi CNT hasil sintesis dilakukan dengan perlakuan asam menggunakan HNO3, yang diikuti netralisasi menggunakan H2O dan pengeringan. Produksi dapat menghasilkan CNT yang memiliki kemurnian 99% dengan kapasitas 228,35 kilogram per tahun. Argon recovery dilakukan untuk menghemat penggunaan gas argon sampai dengan 85%. Proses produksi keseluruhan membutuhkan lahan 15 m2 dan konsumsi energi 209203 kJ/hari. CNT yang diproduksi memiliki harga jual Rp5.300 per gram. Hasil analisis keekonomian menunjukkan nilai IRR sebesar 18,88%, NPV sebesar Rp1.281.356.353, dan payback period kurang dari 5 tahun. Hal ini menandakan pengembangan produksi CNT menguntungkan secara investasi sehingga dapat membuka peluang pembangunan fasilitas produksi CNT dengan harga jual lebih murah di Indonesia. ......Demand of carbon nanotube (CNT) in Indonesia is increasing every year. Until this time, CNT production and commercialization is constrained by expensive processes. CNT carbon source that is potential because of its low price is liquified petroleum gas (LPG). To realize the CNT production in Indonesia, techno-economic analysis of CNT production from LPG is needed. CNT is produced by chemical vapor deposition (CVD) method using Fe-Co-Mo/MgO catalyst. Production is done using fluidized bed reactor equipped by cyclone for separating CNT from residual gas. CNT synthesis in the reactor is done at temperature 900oC and pressure 1 atm. CNT purified with HNO3 acid treatment, followed by netralization using H2O and drying. The process produce 99% purity CNTs with capacity 228.35 kilograms per year. Argon recovery is applied on the process to reduce argon utilization up to 85%. Whole process required 15 m2 space and 209203 kJ/day energy consumption. CNT produced would have IDR 5300 selling price. Economic analysis result shows it have 18.88% on IRR, IDR 1,281,356,353 on NPV, and less than 5 years on payback period. These values shows that CNT production is a profitable investation and could open opportunity for developing CNT production with low price in Indonesia.

Abstrak :
The present study focuses on the characterization of carbon nanotubes (CNTs) synthesized from flame under an atmospheric condition. A laminar flame burner was utilized to establish a rich premixed propane/air flame at the equivalence ratio ? = 1.8–2.2. The flame was impinged on a stainless steel wire mesh coated with nickel (Ni) catalyst to grow CNTs. Distribution and yield of the CNTs on the substrate were quantified. Carbon nanotubes formed on the substrate were harvested and characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and thermogravimetric analysis (TGA). The FESEM micrograph showed that the CNTs produced were in disarray. The synthesized CNTs were an average of 50–60 nm in diameter while the length of the tubes was in the order of microns. TGA analysis showed that 75% of CNTs were present in the sample and the oxidation temperature was 510°C.

Abstrak :
Carbon Nanotubes-Titania (CNT-TiO2) composite that coated on diaper have been synthesized and tested for the removal of ammonia (self-cleaning test) and Candida albicans fungi (self-sterilizing test) that cause odor and make Candidiasis disease, respectively. The composite was characterized by FTIR, FESEM-EDX, XRD, and UV-Vis DRS. XRD and UV-Vis DRS results showed that the CNT-TiO2 composite has a high crystalline and low band gap. The results of self-cleaning and self-sterilizing tests showed that the optimum composition of the composite was 1-3 % wt of CNT and 97-99% wt of TiO2. Acid treatment at pH 1 were accompanied by ultrasonic agitation is an appropriate conditions on the composite synthesis. Within 2 hours of testing the modified diapers, the optimum composite can remove ammonia and Candida albicans by 91 and 98 %, respectively. Based on the experiment results, ammonia and fungi on the modified diapers was able to be removed up to minimum standard to prevent odor and diaper rash

Abstrak :
The production of Carbon Nanotubes (CNT) has a problem with the limited results of Aligned CNT (ACNT) products, due the fact that an effective and economical method has not yet been discovered. This research used catalytic decomposition of methane with the Water-Assisted Chemical Vapor Deposition (WA-CVD) method by using a bench-scale plate structured catalyst reactor and a fixed bed reactor. The Fe-Ni/Al2O3 Catalyst prepared by sol-gel/dip-coating and Ni-Cu-Al Catalyst prepared by co-precipitation were used to make the CNT. Transmission Electron Microscope (TEM) results show there are various types of nanocarbons produced, such as CNT, bamboo-shaped CNT and also quasi-spherical carbon onion shapes. Based on comparative results without adding the water vapor method, ACNT, which were obtained with WA-CVD, tend to grow vertically, even though they have not yet formed neat and uniform shapes. In addition, an increased number of CNT have high purity results. It shows that the role of water vapor significantly improves the quality of CNT.

Abstrak :
The potential of carbon nanotubes (CNTs) produced in our laboratory to be used for hydrogen storage was tested in this study. The test includes the determination of the hydrogen gas adsorption capacity and the dynamics of the adsorption and desorption of hydrogen on CNTs at isothermal temperature of 25oC and pressures of 0–1,000 psia. A similar test was also conducted on commercial CNTs obtained from the Chinese Academy of Sciences for comparison. The results showed that the hydrogen adsorption capacity of the local CNTs is lower than that of commercial CNTs. At pressures around 960 psia, the adsorption capacities of local and commercial CNTs are 0.09% and 0.13% weight, respectively. In general, the hydrogen adsorption data of both the adsorbents can be represented well by the Langmuir model, with less than 3% absolute average deviation (AAD). The dynamics of adsorption and desorption can be represented well by the Gasem and Robinson model with less than 2% AAD. The adsorption and desorption processes on both local and commercial CNTs occurred very quickly. At the highest pressure (960 psia), the adsorption and desorption equilibriums on the local CNTs were reached in approximately 30 s, while on commercial CNTs, they were reached in 2 s. The rates of the adsorption equilibriums on both local and commercial CNTs increase at a higher pressure. In the desorption process, while the equilibrium time is reached slightly faster at a higher pressure on commercial CNTs, the time is almost similar at all pressures for local CNTs.

Abstrak :
Aplikasi Carbon nanotube (CNT) dalam metode pengobatan kanker dapat dilakukan karena menghasilkan selektivitas dan efektivitas targeting obat yang tinggi. Fungsionalisasi CNT diperlukan untuk memperbaiki dispersibilitas, solubilitas, dan toksisitas CNT. Fungsionalisasi dilakukan secara kovalen dengan oksidasi asam yang terdiri dari campuran HNO3 dan H2SO4 dengan penambahan asam klorida (HCl). Variasi yang dilakukan adalah konsentrasi HCl 6M, 8M, 10M, dan 12M pada suhu sonikasi C. CP-­f dikarakterisasi dengan uji dispersi, Fourier Infrared Transformation Spectroscopy (FTIR), Thermal Gravimetry Analysis (TGA), UV-­Vis Spectroscopy, Electron Miscroscopy-­Energy Dispersive Spectroscopy (SEM-­EDS), dan Brine Shrimp Lethality Test (BSLT). Hasil penelitian menunjukkan bahwa CP-­f dengan penambahan HCl 10M (CPf-­3) menghasilkan persen solubilitas tertinggi 11,46% dan suspensi dispersi yang paling stabil pada hari ke-­51. Disamping dari peningkatan dispersibilitas dan solubilitas, morfologi sampel CPf-­3 membentuk beberapa aglomerat yang mengarahkan pada kemunculan sifat dengan nilai LC50 355,62 ppm ......Carbon nanotube application in cancer treatment methods is selected due to its high selectivity and effectivity in drugs targeting delivery. Functionalization is needed to improve dispersibility, solubility, and toxicity of CNT. CNT is treated covalently by oxidation which consist of HNO3 and H2SO4 with the addition of HCl. Variation is performed in HCl concentration of 6M, 8M, 10M, and 12M at sonication temperature of The addition of HCl in certain molarity increase the purity and dispersion time on functionalized CNT (CP-­f). CP-­f were characterized through dispersion test, Fourier Infrared Transformation Spectroscopy (FTIR), UV-­Vis Spectroscopy, Thermal Gravimetry Analysis (TGA), Electron Miscroscopy-­Energy Dispersive Spectroscopy (SEM-­EDS), and Brine Shrimp Lethality Test (BSLT)The study resulted that CP-­f with HCl 10M addition (CPf-­3) produce the highest solubility for 11.46% and the most stable dispersion suspension in 51 days. Besides, CPf-­3 morphology shows some agglomerates which indicate to toxicity with LC50 of 355,62 ppm

Abstrak :
The effect of metal doping on the hydrogen physisorption energy of a single walled carbon nanotube (SWCNT) is investigated. Unlike many previous studies that treated metal doping as an ionic or charged element, in this study, lithium and magnesium are doped to an SWCNT as a neutral charged by substituting boron on the SWCNT (Boron substituted SWCNT). Using ab initio electronic structure calculations, the interaction potential energies between hydrogen molecules and adsorbent materials were obtained. The potential energies were then represented in an equation of potential parameters as a function of SWCNT diameters in order to obtain the most precise potential interaction model. Molecular dynamics simulations were performed on a canonical ensemble to analyze hydrogen gas adsorption on the inner and outer surfaces of the SWCNT. The isosteric heat of the physical hydrogen adsorption on the SWCNT was estimated to be 1.6 kcal/mole, decreasing to 0.2 kcal/mole in a saturated surface condition. The hydrogen physisorption energy on SWCNT can be improved by doping lithium and magnesium on Boron substituted SWCNT. Lithium-Boron substituted SWCNT system had a higher energy physisorption that was 3.576 kcal/mole compared with SWCNT 1.057–1.142 kcal/mole. Magnesium-Boron substituted SWCNT system had the highest physisorption energy that was 7.396 kcal/mole. However, since Magnesium-Boron substituted SWCNT system had a heavier adsorbent mass, its physisorption capacity at ambient temperature and a pressure of 120 atm only increased from 1.77 wt% for the undoped SWCNT to 2.812 wt%, while Lithium-Boron substituted SWCNT system reached 4.086 wt%.