Agus Haryono

Preparation of Magnetite Nanoparticles by Thermal Decomposition of Iron (III) Acetylacetonate with Oleic Acid as Capping Agent

The thermal decomposition of organometallic compounds was used to synthesize magnetite nanoparticles in high boiling point organic solvent containing stabilizing surfactants. Iron (III) acetylacetonate was used as the organometallic precursor in this work. Thermal decomposition of cationic metal center leads directly to the metal oxide, in the presence of 1,2-hexadecanediol, oleylamine, and oleic acid in diphenyl ether. Characterization with the Particle Size Analyzer (PSA) showed the size of the obtained magnetite nanoparticles was 2.1 ± 0.9 nm with polydispersity index of 0.327. The morphology and chemical structure of the obtained magnetite nanoparticle was characterized by using of Transmition Electron Microscopy (TEM) and Fourier-Transformed Infrared (FTIR) spectroscopy. The application of magnetite nanoparticles in the industrial wastewater treatment was also discussed.

Synthesis and properties of castor oil based polyurethanes reinforced with double-decker silsesquioxane

Hybrid polyurethanes with double-decker silsesquioxane (DDSQ) in the main chains were synthesized using castor oil and isophorone diisocyanate (IPDI) as feedstock. Double-decker octaphenylsilsesquioxanetetraol (DDSQ) was prepared and characterized by 1H NMR and MALDI-TOF–MS. Meanwhile, FTIR, TGA, DSC, SEM, UV–Vis spectrophotometer, tensile test techniques and static contact angle were also carried out to investigate the structures and properties of the hybrid polyurethanes. The DDSQ-containing hybrid polyurethanes exhibited improved thermal stability in terms of thermogravimetric analysis (TGA). DSC analysis demonstrated that the hybrid polyurethanes with DDSQ displayed enhanced glass transition temperature. According to the results of SEM and UV–Vis spectrophotometer, the aggregates of DDSQ were dispersed homogeneously in the hybrid polyurethanes matrix. With the inclusion of DDSQ, the hydrophobicity of the hybrid material was significantly improved as the results of the static contact angles revealed.

Effect of Chitosan and Liposome Nanoparticles as Adjuvant Codelivery on the Immunoglobulin G Subclass Distribution in a Mouse Model

Background We investigate the immunogenic properties of chitosan and liposome nanoparticles as adjuvant codelivery against a commercial pneumococcal conjugate vaccine (PCV) in an animal model. Methods The chitosan and liposome nanoparticles were prepared by ionic gelation and dry methods, respectively. The PCV immunization was performed intradermally in the presence of adjuvants and booster injections which were given without an adjuvant. The Quil-A® was used as a control adjuvant. The ELISA was performed to measure the antibodies against pneumococcal type 14 polysaccharide (Pn14PS). Results The level of total antibodies against Pn14PS antigen was no different between the mouse groups with or without adjuvant codelivery. Codelivery of the PCV with chitosan nanoparticles as well as the Quil-A adjuvant elicited IgG1, IgG2a, IgG2b, and IgG3 antibodies. Meanwhile, codelivery of liposome nanoparticles elicited mainly IgG1 antibodies against the Pn14PS. Conclusions The chitosan and liposome nanoparticles as adjuvant codelivery were successfully synthesized. These nanoparticles have different shapes in particle formation, liposome nanoparticle with their unilamellar shape and chitosan nanoparticles in large shape due to the aggregation of small-size particles. Codelivery of chitosan nanoparticles has more effect on the IgG subclass antibody production than that of liposome nanoparticles in a mouse model.

Effect of Size of Cellulose Particle as Filler in the PVC Biocomposites on their Thermal and Mechanical Properties

The combination between synthetic polyolefin with natural polymer such as cellulose, starch and chitosan can stimulate biodegradation processes of waste plastics such as polyethylene (PE), polypropylene (PP) and other conventional plastics. In this work, PVC (polyvinyl chloride) biocomposite was prepared by compounding cellulose particle into PVC matrix in the presence of PVC-g-maleic anhydride as a compatibilizer. Cellulose nanoparticles were prepared by physical top-down method after milling by using High-Energy Ball-mill. The diameter size of cellulose nanoparticle was obtained as 170 nm. Cellulose particles were added as filler with ratio of 10-30 phr in PVC matrix. PVC biocomposites was prepared as a sheet film with the thickness of 0.3 mm by hot-press method. The addition of cellulose particle into PVC matrix was examined in various filler volumes and various cellulose particle sizes. The obtained PVC composite films were characterized by means of Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and Fourier-Transformed Infrared (FTIR) spectroscopy. The rheological and mechanical properties of PVC and cellulose composites were investigated as a function of surface structure and filler volume fraction.

Sulfonation of Waste High Impact Polystyrene from Food Packaging as a Polymeric Flocculant

Sulfonation of waste high impact polystyrene from commercial food packaging was studied in this work. The obtained sulfonated polystyrene was characterized by using Fourier Transformed Infrared spectroscopy. Effect of the reaction time and temperature on the degree of sulfonation was observed. Waste high impact polystyrene resin from food packaging showed degree of sulfonation at 72.2% level. This degree of sulfonation was lower than the same reaction on pure polystyrene and pure high impact polystyrene, which showed degree of sulfonation at 97.7% and 85.2% level, respectively. Simulation of flocculation test using kaolin suspension was conducted to evaluate the application of sulfonated polystyrene as a polymeric flocculant.

Influence of palmitoyl pentapeptide and Ceramide III B on the droplet size of nanoemulsion

The influence of the Palmitoyl Pentapeptide (PPp) and Ceramide IIIB (Cm III B) as active ingredients on the droplet size of nano-emulsion was studied using different kinds of oil (avocado oil, sweet almond oil, jojoba oil, mineral oil and squalene). The formation of nano-emulsions were prepared in water mixed non ionic surfactant/oils system using the spontaneous emulsification mechanism. The aqueous solution, which consist of water and Tween® 20 as a hydrophilic surfactant was mixed homogenously. The organic solution, which consist of oil and Span® 80 as a lipophilic surfactant was mixed homogenously in ethanol. Ethanol was used as a water miscible solvent, which can help the formation of nano-emulsion. The oil phase (containing the blend of surfactant Span® 80, ethanol, oil and active ingredient) and the aqueous phase (containing water and Tween® 20) were separately prepared at room temperatures. The oil phase was slowly added into aqueous phase under continuous mechanical agitation (18000 rpm). All samples were subsequently homogenized with Ultra-Turrax for 30 minutes. The characterizations of nano-emulsion were carried out using photo-microscope and particle size analyzer. Addition of active ingredients on the formation of nano-emulsion gave smallest droplet size compared without active ingredients addition on the formation of nano-emulsion. Squalene oil with Palmitoyl Pentapeptide (PPm) and Ceramide IIIB (Cm IIIB) gave smallest droplet size (184.0 nm) compared without Palmitoyl Pentapeptide and Ceramide IIIB (214.9 nm), however the droplets size of the emulsion prepared by the other oils still in the range of nano-emulsion (below 500 nm). The stability of nano-emulsion was observed using two methods. In one method, the stability of nano-emulsion was observed for three months at temperature of 5°C and 50°C, while in the other method, the stability nano-emulsion was observed by centrifuged at 12000 rpm for 30 minutes. Nanoemulsion with active ingredient was remained stable even when stored until three months. Coalescence process between the droplets was not occurred significantly and droplet size was still below 500 nm. Over all, the emulsion remained stable, even it was centrifuged at 12000 rpm for 30 minutes.

Numerical simulation of single electron transistor using master equation

In this work, simulation technique for single electron transistor (SET) based on master equation is presented. The SET is modeled as a circuit consisting of two tunnel junctions, one non-tunnel junction and two voltage sources of gate voltage and drain voltage. A tunneling electron is described as a discrete charge due to stochastic nature of a tunneling event. Simulated source-drain current versus drain voltage characteristics show the staircase behavior, while source-drain current is a periodic function of the gate voltage. Coulomb diamond region is also found, which means that the SET operation is based on single electron tunneling. These results reproduce the previous studies of the SET, indicating that the simulation technique achieves good accuration. Such simulation method is also useful in the application of single electron turnstile, single electron pump and the other more complex multiple tunnel junction circuits.

Effect of Concentration on the Ionic Interaction between Polystyrene Sulfonate and Cationic Surfactant in Aqueous Solution

Polystyrene sulfonate (PSS) were prepared by sulfonation method of polystyrene using sulfuric acid. Abundant amount of polystyrene waste can be reused as a coagulant, membrane for polymer fuel cell and anionic-cationic polymer interactions. The characterization of PSS was carried out by using UV-Vis, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectra, molecular weight and analysis of sulfonation degree. The degree of sulfonation was obtained at 94,18%. Ionic interaction between anionic polymer PSS and cetyltrimethylammonium bromide (CTAB) as cationic compound in aqueous solution were analyzed by using dynamic light scattering (DLS), conductometry and fluorimetry. Behavior of conductivity have been calculated the critical micelle concentration (cmc). The FTIR and 1H-NMR spectra showed the ionic interaction between PSS and CTAB. This ionic interaction can be controlled by changing the polymer concentration.

PREPARASI DAN KARAKTERISASI KOPOLIMER VINIL ASETAT DAN ASAM AKRILAT -Cu SEBAGAI BIOSIDA UNTUK ANTIFOULING

PREPARASI DAN KARAKTERISASI KOPOLIMER VINIL ASETAT DAN ASAM AKRILAT -Cu SEBAGAI BIOSIDA UNTUK ANTIFOULING . Perkembangan teknologi navigasi pada saat ini sangat dibutuhkan, salah satunya dengan penggunaan biosida antifouling untuk efisiensi bahan bakar. Mengingat pentingnya biosida untuk anti fouling maka perlu dilakukan penelitian untuk mencegah terjadinya fouling pada material yang terendam air laut. Pada penelitian ini dikembangkan proses polimerisasi untuk menghasilkan biosida. Biosida disintesis dengan mereaksikan monomer-monomer asama krilat dan vinil asetat yang ditambah CuprousOxide (Cu2O)melalui reaksi polimerisasi membentuk kopolimer. Pada proses polimerisasi tersebut digunakan inisiator Benzoyl PerOxide (BPO), dengan variabel perbandinganmol monomer 1:1 dan 1:2, konsentrasi Cu 2 O 1%; 5% dan 15%, serta digunakan pula etanol 93% sebagai pelarut. Polimerisasi selama 3 jam. Struktur dari kopolimer tersebut dikarakterisasi menggunakan Fourier Transform-Infra Red (FT-IR), Nuclear Magnetic Resonance (NMR) Spektrofotometer, dan Atomic Absorption Spectrophotometer (AAS). Hasil penelitian mengindikasikan bahwa poli(asam akrilat-ko-vinil asetat-Cu) telah berhasil dipreparasi.

Preparation and Characterization of Polyhedral Octaphenylsilsesquioxane Modified Castor oil based Polyurethane

Vegetable oil-based polyurethanes were synthesized using castor oil (CO) as feedstock, which were characterized by their environmental friendly and renewable properties. Aiming to compensate for shortcomings of these materials, a series of polyurethane/polyhedral octaphenylsilsesquioxane (OPS) hybrids with different OPS contents were prepared by physical mixing in the solutions. Thereafter?chemical structure?morphology and thermal properties of hybrids were characterized through Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), tensile test techniques and static contact angle. The results show that the hybrid polyurethanes display both enhanced glass transition temperatures (Tg), initial decomposition temperature (Td5) and tensile strength with low OPS contents. While with high contents?these values decline with the severe aggregation of nano-particles as shown in the SEM images. Meanwhile, the hybrid polyurethanes displayed enhanced surface hydrophobicity as the contact angle with water revealed