Bambang Sunendar
Institut Teknologi Bandung, Engineering Physics, Faculty Member
ABSTRACT Iron foam is a type of material having potential to be used as water or air filter andimplant material. One of the limitations of this material is its high reactivity on corrosion. In thepresent research TiO2 coating on iron foam... more
ABSTRACT Iron foam is a type of material having potential to be used as water or air filter andimplant material. One of the limitations of this material is its high reactivity on corrosion. In thepresent research TiO2 coating on iron foam substrate has been developed by self-assembledmonolayer method. Focus is given on the effect of TiCl4 and chitosan concentration on thecharacteristic of the developed TiO2 layer. Precursor was prepared with HCl concentration of 0.5; 1;1.5 M and chitosan solution concentration of 1% ; 2% ; 4% (w/v). Scanning Electron Microscopy(SEM) and Energy Dispersive Spectroscopy (EDS) characterizations show that TiO2 particles areformed on the iron foam surfaces. It was observed that with the higher TiCl4 concentration moreTiO2 particles obtained on substrate surfaces. On the other hand, SEM results also show the averageTiO2 particles size at around 1 micrometer and in tetragonal shape. It was observed that with thehigher chitosan concentration, the particles shape tend to have tetragonal stucture, while at lowerchitosan concentration (1%), agglomeration of TiO2 particles were observed.
Research Interests:
Abstract Porous ceramics were produced by mixing clay and ash of sago waste from the sago processing industry in Indonesia. The composition was prepared by adding an amount from 0 to 40 wt% of ash into the clay, and then the samples were... more
Abstract Porous ceramics were produced by mixing clay and ash of sago waste from the sago processing industry in Indonesia. The composition was prepared by adding an amount from 0 to 40 wt% of ash into the clay, and then the samples were milled for 6 h. The samples were dry pressed and sintered in the temperature range between 900 o C and 1300 o C. The influence of the ash content and the sintering temperature on the bulk density, firing shrinkage, and porosity was studied in detail. The results show that an amount of 10 wt% ...
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ABSTRACT Microencapsulation is a new breakthrough in the field of nanotechnology that can be used for various applications, in particular for the application of controlled release material for functional textiles which were added by... more
ABSTRACT Microencapsulation is a new breakthrough in the field of nanotechnology that can be used for various applications, in particular for the application of controlled release material for functional textiles which were added by certain active substances and gave effects when used such as fragrance and anti mosquito textile. In this research, the synthesis of silica-lavender microencapsulation for anti-mosquito textile had been conducted successfully via sol-gel emulsion process. Sodium silicate solution which was emulsified into the lavender oil as an active ingredient acted as oil phase and ethanol solution acted as water phase. The addition of chitosan as surfactant and polymer for encapsulation with starch as soft template affected the rod-structure formation of nanorod. SEM result showed the morphology of silica-lavender. The rod has the average diameter size of 0.042-0.206 μm. The optimum result of rod-structure was obtained by adding 1% (v/v) of chitosan. FTIR analysis indicated the presence of absorbance peaks at wavenumber of 1411.89, 958.62, and 1078.2 cm-1 respectively for C-H (alkanes), C-H (alkenes) and ester functional groups which indicated the lavender compound in silica-lavender. UV-Vis analysis showed the maximum absorbance at wavelength of lavender at 350 nm. The combination of morphology and chemical properties of silica-lavender modified by chitosan-starch made this material as a candidate material for application in functional textile.
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ABSTRACT In the present investigation, nanocrystalline silica xerogel (NSX) powders were produced from an amorphous silica xerogel (ASX) extracted from sago waste ash. The NSX powders have been calcined at 1200oC, milled and then annealed... more
ABSTRACT In the present investigation, nanocrystalline silica xerogel (NSX) powders were produced from an amorphous silica xerogel (ASX) extracted from sago waste ash. The NSX powders have been calcined at 1200oC, milled and then annealed at temperatures ranging from a room temperature to 1200oC. Their properties (and most notably the size of the particles) have been characterized on the basis of the experimental data obtained using thermal analysis (DSC/TGA), X-ray diffraction (XRD), Infrared and Raman spectroscopy. For the crystalline silica xerogel powders the results show a narrow distribution of the particle sizes centered around an average value of 636 ± 67 nm. The DSC analysis of NSX indicates that in the temperature range from a room temperature to 300oC five distinct stages of the crystallization process take place, which are delimited by the transition temperature of 38oC, 92oC, 129oC, 168oC, and 246oC, respectively. Above 300oC, the crystalline phase is similar to an amorphous silica xerogel (ASX), i.e. cristoballite-like and tridymite-like crystalline silica phases confirmed by the XRD analysis. It has been observed that the characteristic band of cristoballite is strongly dependent on the thermal history and the NSX transforms into a stable form at a temperature of 1200oC. Both the Raman and the FTIR spectra elucidate the bonding system of the constituent atoms and groups (such as Si, O and OH) and throw light on their underlying structure. The obtained results are important for optimization of the parameters of the technological processes for production of nanocrystalline silica glass ceramics used as a host matrix for luminescence materials, each of which requires a specific porosity and structure.
Research Interests:
Research Interests:
The global need of biomaterial products especially in bone clinical application increases every year. The gold methods like autograft and allograft have some limitations in the application such as the availability of donor sites,... more
The global need of biomaterial products especially in bone clinical application increases
every year. The gold methods like autograft and allograft have some limitations in the application
such as the availability of donor sites, antigenicity issues, the high cost, etc. To solve the problems,
many researches and activities in the field of biomaterial have been conducted continuously in the
past decades to develop the proper synthetic materials for bone substitutes which have properties
similar to bone tissue. In this research, the synthesis of biocomposite for bone scaffold application
prepared by freeze drying method has been done successfully. The materials used are biopolymer
(alginate and chitosan) and bioceramics (carbonate apatite) with certain mixing variations. SEM
result showed that the pores obtained by freeze drying method can mimic the pores of actual bone
thus they will be able to resemble cells microenvironment, enhance interface interaction, and
support cell proliferation. The existence of carbonate apatite on the scaffold’s surface can be
observed with particle size of 0.05 – 1 μm and has been dispersed evenly. These results are in good
agreement with FT-IR analysis that indicates the presence of PO4
3– functional group on the scaffold
at wave numbers 569 and 1041.56 cm–1 and CO3
2– functional group at wave number 1411.89 cm–1.
The in vitro biological evaluation of HeLa cells which exposed to extract solution of scaffold (in
some variations of concentration) indicated that the scaffold obtained was not cytotoxic to the HeLa
cells.
every year. The gold methods like autograft and allograft have some limitations in the application
such as the availability of donor sites, antigenicity issues, the high cost, etc. To solve the problems,
many researches and activities in the field of biomaterial have been conducted continuously in the
past decades to develop the proper synthetic materials for bone substitutes which have properties
similar to bone tissue. In this research, the synthesis of biocomposite for bone scaffold application
prepared by freeze drying method has been done successfully. The materials used are biopolymer
(alginate and chitosan) and bioceramics (carbonate apatite) with certain mixing variations. SEM
result showed that the pores obtained by freeze drying method can mimic the pores of actual bone
thus they will be able to resemble cells microenvironment, enhance interface interaction, and
support cell proliferation. The existence of carbonate apatite on the scaffold’s surface can be
observed with particle size of 0.05 – 1 μm and has been dispersed evenly. These results are in good
agreement with FT-IR analysis that indicates the presence of PO4
3– functional group on the scaffold
at wave numbers 569 and 1041.56 cm–1 and CO3
2– functional group at wave number 1411.89 cm–1.
The in vitro biological evaluation of HeLa cells which exposed to extract solution of scaffold (in
some variations of concentration) indicated that the scaffold obtained was not cytotoxic to the HeLa
cells.
Research Interests:
Carbon with nanostructure, is a material that currently being developed in recent years. It is one of the unique materials, showing excellent and unique physical and chemical properties, including high electrical and thermal... more
Carbon with nanostructure, is a material that currently being developed in recent years. It is one of the unique materials, showing excellent and unique physical and chemical properties, including high electrical and thermal conductivities, high surface area, high mechanical strength, and chemically inert. Its interesting properties did not only improve the capabilities of the existing equipment but also it could be developed to be a variety of novel equipment. The commercial carbon nanostructure in this research was prepared by a technology process which is relatively much simpler than the process of the existing commercial carbon nanostructures in the market. In this study, catalytic graphitization processing was performed by using cellulose from Oryza sativa pulp as a precursor and iron (III) chloride hexahydrate as a catalyst. Chemical and mechanical treatments were carried out to separate the cellulose from Oryza sativa pulp. Catalyst impregnation into cellulose was carried out by heating a mixture of cellulose and the catalyst in an oven up to 48 hours. Graphitization process was then performed at temperatures of 600-800°C in an inert atmosphere of N 2 for two hours. Based on XRD analysis results, the peak at diffraction angel 2 of 26° was observed, corresponding to the (002) crystal plane orientation of the graphite structure. The characterization results of FT-IR Spectrophotometer showed the aromatic functional group, indicating the presence of C = C bond at the wave numbers of 1500-1650 cm-1 which is the basis of the graphite structure; while the peak appearance at the wavenumbers of 480-510 cm-1 was corresponded to the characteristics for the Fe-O interaction. SEM results showed that the carbon nanostructures were 30-80 nm in diameter and had the length of up to 2 m. However, TEM results showed the formation of carbon nanocoil-based graphite with the formation of transition carbide compounds to produce graphite.