Search

The design innovation and composition of TiO2 as a photoanode have been continuously studied in recent years to improve the photoconversion performance of Dye-sensitized Solar Cells (DSSC). The important components in the formation of TiO2 paste are solid content, solvents, and organic compounds as binders. In terms of solvents, water or simple alcohol are not suitable for screen printing methods, because cracking will occur after the annealing process by rapid evaporation. In this report, we investigated the addition of nitric acid (HNO3) and ethyl cellulose (CH2CH3) as a binder for optimize the overall DSSC performance. TiO2 photoanode was synthesized by screen printing method through the initial stage of making blocking layer with spin coating method. The effect of nitric acid and ethyl cellulose on, TiO2 powder was studied intensively to determine the best photoconversion performance. TiO2 films were prepared by varying the process without and with post-treatment. The XRD pattern confirmed the presence of a pure anatase phase of TiO2. The morphology of the photoanodes surface area were studied through SEM characterization. The characteristics of J-V shows an increasing in photocurrent and efficiency through the post-treatment process. DSSCs based on TiO2-HNO3 photoanode with post-treatment exhibited a highest efficiency of 3.59%. We found that the sample with post-treatment process have a smaller impedance than sample without post-treatment with charge transfer resistance (RCT) of 10 Ω and 23 Ω, respectively. It may indicate that the TiO2 film with post-treatment have a better interconnection then charge transfer and charge extraction process are more effective and resulting higher efficiency. [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte (SPE) based on Ch-g-PMMA – Magnesium Triflate (MgTf) incorporating with Ethylene Carbonate (EC) as plasticizers has been prepared. SPE was first prepared by dissolving polymer Ch-g-PMMA with magnesium triflate (MgTf) (10-50 wt.%) with 1% acetic acid. A different weight percentage (10-50 wt.%) of ethylene carbonate (EC) was added to the best conductivity of Ch-g-PMMA with 40 wt.% MgTf. Ionic conductivity values were calculated from the bulk resistance obtained from impedance plotted at frequency range of 100 Hz to 1 MHz. The ionic conductivity increases as weight percentage of EC increases. The highest conductivity obtained was 1.07×10−3 S.cm-1 at 50 wt.% of EC. This ionic conductivity is studied at the 298 K (room temperature). Molecular interaction between components in each electrolyte system were analyzed through Fourier Transform Infrared Spectroscopy (FTIR). The complexations between the materials used in electrolyte systems are based on shifting of the bands, changes in intensity, shape and existence of some new peaks in FTIR spectra. X-Ray Diffraction (XRD) was used to investigate the crystallographic structure and chemical composition of all samples. The intensity of XRD peaks decreased as more EC added into the system reducing the crystallinity. The Ch-g-PMMA–40 wt.% MgTf–50 wt.% EC are believing as the best system for this study. [ABSTRACT FROM AUTHOR]

In this study, hydrogel neutral electrolyte was synthesized from PVA/HEC (polyvinyl alcohol/ hydroxyl ethyl cellulose) using CA (citric acid) as the chemical crosslinking. The neutral electrolyte of Na2SO4 (sodium sulphate) was used to obtain higher cell voltages of supercapacitor. To investigate the performance of the flexible supercapacitor, we varied the concentration of CA (0-30%). The supercapacitor consisted of the hydrogel and two activated carbons which were assembled in between. The resulted supercapacitors were then characterized using FTIR (Fourier Transform Infrared) to evaluate the chemical bond formation in the hydrogel electrolyte. Electrochemical characteristic of the supercapacitors was also analyzed by EIS and cyclic voltammetry measurements. The results showed that the addition of 15% and 30 % CA yielded the crosslinking reaction of PVA/HEC as represented by reduction of O-H groups and the existence of C=O groups. The hydrogel of 15% CA produced the lowest ESR (Equivalent Series Resistance) of 45 Ω and the highest specific capacitance of 43.05 F/g. Therefore, it can be concluded that hydrogel neutral electrolyte of PVA/HEC can be utilized as a high voltage flexible supercapacitor. [ABSTRACT FROM AUTHOR]

Curcuminoids, natural polyphenolic compounds extracted from the rhizomes of turmeric (Curcuma longa L), are known to have antioxidant, anti-inflammatory, anti-carcinogenic, antiviral, and antifungal actions. It is also known that the delivery of curcuminoids for local and treatment of gastric disorders, such as gastric ulcers, can use gastro-retentive floating (GRF) devices. The purpose of this research is to formulate and evaluate a floating tablet of curcuminoids that have a longer residence time in the stomach for the treatment of gastric ulcers. The GRF tablets were formulated by mixing the extract of turmeric that contains curcuminoids with low-density hydroxypropyl methylcelluloses (HPMC) polymers, such as HPMC K4M, HPMC E15, and ethyl cellulose (EC) in different weight ratios. An effervescent agent that can form a floating system was also added. The GRF tablets were prepared using the direct compression technique. The characterization of the tablet included the weight variation, hardness, friability, drug loading, in vitro dissolution studies, and floating lag time. The combination of ethyl cellulose and HPMC K4M in the formulation of GRF tablet showed good characteristics of mass uniformity, hardness, and friability, as well as low floating lag time and high curcuminoids cumulative release in the stomach. The result showed that the GRF tablet has potential as a floating system for delivering curcuminoids to the gastric area via oral administration. [ABSTRACT FROM AUTHOR]

The writers conducted a study about the synthetic and characterization of poly(lactic acid)/ ethyl cellulose/ hydroxyapatite composite with the addition of sodium trimetaphosphate as a cross-linker for bone scaffold application. The purpose was to find out the impact of sodium trimetaphosphate concentration variation on scaffold to get the best mechanical and physical properties to be applied as bone scaffold in accordance with standard. This research was conducted by using a simple mixing method and freeze drying as the equipment for drying purpose. Scaffold was soaked in a solution of sodium trimetaphosphate with the concentration variation are 6%; 8%; 10%; 12%; 14% w/v. The characterization of mechanical and physical properties test at scaffold showed the characteristic which meets the standard of mechanical and physical properties for human bone. The result of FTIR spectra indicate the presence of formed chemical bond between cellulose and sodium trimetaphosphate. According to the result, the best performance of scaffold was obtained by 14% sodium trimetaphosphate concentration, which has a pore size value of 100 – 249 µm, compressive strength 5.37 MPa and porosity 63.17%. Based on the result of the characterization, scaffold with the addition of sodium trimetaphosphate as a cross-linker have fulfilled criteria for bone regeneration. [ABSTRACT FROM AUTHOR]

Interpolation is widely applied numerical technique to capture the relation between dependent and independent variables in technology and sciences. Lagrange interpolation is applied when the independent variable values are unequally spaced. Because of the standard error involved in measurements of experimental data, the approximate value is only known. Thus, a certain amount of uncertainty prevails. This uncertainty can be expressed using fuzzy numbers. The proposed study discusses about the cisplatin drug release. This uses Aurum (gold) and iron oxide nanoparticles to synthesize ethyl cellulose/cisplatin iron oxide nano capsules and ethyl cellulose/cisplatin Aurumnano capsules to analyze the effect of these nanoparticles in the cisplatin drug release and to develop fuzzy Lagrange interpolation which can be used for further works to understand the impact of the concentration and pH of the system in the amount of drug released. [ABSTRACT FROM AUTHOR]

Polymers can be found in almost every part of a transdermal patch; as matrix-formers, in manufacturing rate controlling membranes, pressure sensitive adhesives, liners and backing layers. Because of this, they have to posess elasticity, transparency, hydro/lipophilicity, durability, hardness, etc. As matrix is considered the backbone of transdermal patches, in order to be used for this purpose, polymers have to have good mechanical and adhesive properties, while inhibiting cristallisation of the active ingredient, improving its release and delivery. Polymers most often used for this purpose are cross-linked polyethylene glycol networks, acrylic-acid matrices (Eudragit systems), ethyl cellulose, hydroxypropyl methylcellulose, polyvinyl pyrrolidone, ethyl vinyl acetate copolymer and chitosan. Reservoirs in transdermal patches are made from polymeric hydrogels such as ethyl vinyl acetate and sodium alginate gels. Rate controlling membranes are usually made from ethyl vinyl acetate copolymer, polyethylene, or sodium alginate networks. Pressure sensitive adhesives are made from acrylate polymers, rubbers (natural, styrene/isoprene/styren, and polyisobutilene) and polydimethylsiloxane. The release liner has to be inert and impermeable to water and all components of the patch. It can be made from polyethylene, polyvinyl chloride, polydimethylsiloxane and polyester films. Backing layer serves as protection for the patch, from environmental factors, so it has to be made from durable materials such as polyvinyl alcohol, ethyl vinyl acetate, polyurethane and polyester films. [ABSTRACT FROM AUTHOR]

Effect of EC-PC plasticizers on electrochemical properties of sodium triflate (NaCF3SO3), based PEO-PAM blend electrolyte system has been investigated. Polymer electrolyte samples [PEO50 + PAM50 + 12.5 wt% NaCF3SO3 + x wt% (1:1/EC: PC)] plasticizers with x varying as 5, 10, 15, 20, 25 according to wt% have been prepared using solution cast technique. Differential Scanning Calorimetry has been used to characterize the samples. The electrical properties of materials are studied using impedance spectroscopy in the frequency range of 20 Hz to 2 MHz from room temperature to 333 K. The conductivity increases with the addition of plasticizer in the electrolyte films. Maximum ambient temperature conductivity of 5.74×10−4 S/cm is observed in sample with 15 wt% plasticizer. [ABSTRACT FROM AUTHOR]

Conductive silver paste used for silk-screen printing was prepared with silver nanoparticles as conductive phase, with the mixture of ethyl cellulose, the Span-80, terpineol and other substances as organic vehicle. With different sintering process, the sintering temperature and sintering time on conductive properties of Ag paste were discussed by observing the morphology of the sintered Ag paste with SEM and measuring the resistivity with the four-probe meter. The results show that conductive Ag paste with good conductive property can be obtained via sintering at 350 oC for 40 min. [ABSTRACT FROM AUTHOR]