N2 Gas Flow Research Articles

Structural, Mechanical, and Decorative Properties of Sputtered TiN and Ti (N, C) Films for Orthodontic Applications; an In Vitro Study.

In this paper, we explore and modify the structural, mechanical, and decorative properties of films composed by TiN and Ti (N, C) with a wide range of N2 gas flow during the deposition in order to be used on orthodontic systems. The films were grown using reactive DC magnetron sputtering from a pure Ti target and customized with C pellets onto Si and stainless steel 316L substrates. The structural properties were studied using X-ray diffraction and scanning electron microscopy, while the mechanical ones were obtained through hardness, elastic modulus, and friction coefficient. Moreover, the wear rate has been measured under an artificial saliva medium to simulate the oral cavity. The color of the films deposited onto stainless steel 316 L substrate was characterized through CIELab color code. Our findings show that the addition of N2 and C in the Ti matrix improves the mechanical properties of the films. With the increase in the amount of N2 and C, the hardness reaches a value of 739 HV, higher than the one reported in the literature (600 HV), a low value of the coefficient of elasticity (8.0 GPa), and also a low friction coefficient (0.30). Moreover, with the addition of N2 and C in the Ti films, the color of the films changes from metallic aspect until “with” gold, which means that our coatings exhibit versatile mechanical and color characteristics to be used in orthodontic wires applications.

Synthesis, Characterization, and Adsorption Properties of Highly Microporous Structured Activated Carbon

The aim of this study is to synthesize activated carbon with high surface area from peach kernel shells which is an agricultural waste. In this study, activated carbon synthesis was carried out by using CO2 at 2 different temperatures (800 and 900 °C) with physical activation from products carbonized at 4 different temperatures (300, 400, 500, and 600 °C) and 2 different N2 gas flow rates (100 and 500 mL/min). After carbonization, solid, liquid, and gas yields of the materials were calculated. The surface area of activated carbons synthesized was calculated by BET analysis and the differences in the surface area were shown by changing the synthesis conditions. Surface areas vary between 340.15 and 686.74 m2/g. In samples pores formed were examined by DFT plus. It was found that most of these pores consist of micropores. Also, the structures of the samples were examined with SEM and XRD analyses. Methylene blue removal of the synthesized samples was studied and the results were compared.

Pyrolysis of mustard straw: Evaluation of optimum process parameters, kinetic and thermodynamic study

The aim of this work was to evaluate the pyrolysis of mustard straw (MS) in a thermogravimetric analyser and in a tubular reactor to recognize its bioenergy capability. The model free methods of Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) and Vyazovkin were employed for kinetic analysis and Coats-Redfern (CR) method for elucidating the reaction mechanism. Response surface methodology (RSM) with central composite design technique was employed to optimize the pyrolysis process parameters to gain maximum amount of bio-oil. The highest bio-oil yield (44.69%) was obtained at the heating rate of 25 °C/min and at 500 °C under inert condition (N2 gas flow rate = 100 ml/min). Further, FTIR and GCMS analysis of bio-oil revealed the presence of different functional groups and valuable chemicals, whereas physicochemical characterization revealed its fuel characteristic. The results confirmed the suitability of mustard straw as a feed-stock for obtaining a cleaner fuel and value added products.

Barium Titanium Oxynitride from Ammonia-Free Nitridation of Reduced BaTiO3

We investigated the nitridation of reduced BaTiO3, BaTiO2.60H0.08, corresponding to an oxyhydride with a large concentration of O defects (>10%). The material is readily nitrided under flowing N2 gas at temperatures between 400 and 450 °C to yield oxynitrides BaTiO2.6Nx (x = 0.2−0.22) with a slightly tetragonally distorted perovskite structure, a ≈ 4.01 and c ≈ 4.02 Å, and Ti partially remaining in the oxidation state III. The tetragonal structure was confirmed from Raman spectroscopy. 14N MAS NMR spectroscopy shows a single resonance at 270 ppm, which is typical for perovskite transition metal oxynitrides. However, largely different signal intensity for materials with very similar N content suggests N/O/vacancy ordering when prolonging nitridation times to hours. Diffuse reflectance UV-VIS spectroscopy shows a reduction of the intrinsic band gap to 2.4–2.45 eV compared to BaTiO3 (~3.2 eV). Mott-Schottky measurements confirm n-type conductivity and reveal a slight negative shift of the conduction band edge from –0.59 V (BaTiO3) to ~–0.65 eV.

Preparation and Carbonization of Glucose and Pyromellitic Dianhydride Crosslinked Polymers

In this work, four types of nanosponges were prepared from pyromellitic dianhydride (PMDA) and D-glucose (GLU) with different molar ratios (1.5:1, 2:1, 2.5:1 and 3:1). The obtained PMDA/GLU nanosponges were then pyrolyzed at 800 °C for 30 min under N2 gas flow. The prepared polymeric nanosponges were investigated by FTIR spectroscopy, elemental and thermogravimetric analyses to unravel the role played by the different molar ratio of the precursors in the formation of the polymer. The pyrolyzed nanosponges were investigated by means of porosity measurements, X-ray diffraction analysis, Raman spectroscopy and high-resolution transmission electron microscopy. Notably, no significant correlation of the amounts of used precursors with the porous texture and structure was evidenced. The results corroborate that PMDA and GLU can be easily combined to prepare nanosponges and that the carbon materials produced by their pyrolysis can be associated with glassy carbons with a microporous texture and relatively high surface area. Such hard carbons can be easily obtained and shrewdly used to segregate relatively small molecules and organic contaminants; in this study methylene blue adsorption was investigated.

Modification of structural, thermal and optical properties of PC-PET/CdSe NCP using gamma radiation

In the current study we synthesized a nanocomposite (NCP) from polycarbonate/polybutylene terephthalate (PC-PET) blend and CdSe nanoparticles (NPs) through ex-situ casting methodology. CdSe NPs were synthesized using thermolysis technique with N2gas flow. X-ray diffraction data for CdSe NPs are reported. The Rietveld refinement indicated that the synthesized CdSe acclimatizes cubic zinc blends constitution of a lattice parameter 6.057 Å and an average grain size of 2 nm. The PC-PET/CdSe NCP samples were irradiated by gamma doses between 20 and 230 kGy. The induced variations in the structure, thermal and optical properties of the gamma irradiated PC-PET/CdSe NCP have been illustrated by means of TEM, XRD, TGA, FTIR and UV–vis spectroscopes. The irradiation with doses in the range 50–230 kGy leads to the domination of crosslinking that improves the amorphous content. This increases the degradation temperature from 417 to 432 °C indicative of an enhancement in the thermostability of the NCP samples. Also, the optical band gap is reduced from 4.28 to 3.76 eV which is ascribed to the enhancement in the amorphous content of the irradiated PC-PET/CdSe NCP. This specifies that the gamma irradiation causes a more compactness of the NCP and leads to appropriate spreading of CdSe NPs within the PC-PET matrix. Additionally, the CIE approach was used to describe the colored samples. It is found that the PC-PET/CdSe NCP acquires color due to gamma doses, as the color intensity reached a remarkable color difference larger than 5 (14.9) which is a reasonable challenge in saleable reproduction on printing press.

Foam flushing with soil vapor extraction for enhanced treatment of diesel contaminated soils in a one-dimensional column

A limitation of soil vapor extraction (SVE) remediation for total petroleum hydrocarbons (TPHs) in the unsaturated zone is the inability to remove the less volatile petroleum mixture compounds in diesel fuel. SVE combined with foam flushing may have the potential to enhance dissolution or mobilization of soil sorbed diesel and allow mobilized diesel to move to the SVE extraction well. A nonionic surfactant polyoxyethylene (20) sorbitan monooleate (TW80) was selected for generating foam, and a procedure to incorporate the oxidant sodium persulfate (SPS) in generating TW80/SPS foam to deliver chemical oxidation, was also studied. Both TW80 and TW80/SPS foams exhibited 96–98% quality under 8–32 mM of TW80 and 10–50 mM of SPS. The addition of SPS in TW80 solution resulted in elevated ionic content and degradation of TW80, which may reduce the foam stability and have minor effects on foam quality. Through analysis of interrelationships among column flushing experimental parameters, it was shown that the foam quality was reduced to 42–47% when foam flushed through a diesel contaminated soil column. Moreover, the results of column flushing tests operated for 12 h indicated that the effectiveness of removal of diesel by different foams followed the order of TW80 foam (53%) > TW80/SPS foam (37%) >N2 gas flow alone (3%). It was shown that foam flushing could be an alternative approach, rather than using N2 gas flow alone (SVE), in enhancing SVE for reducing diesel contamination in the unsaturated zone.

Influence of Acetylated Cellulose Nanocrystal Incorporated into Poly(e-Caprolactone) Nanocomposites on Its Thermal, Mechanical, and Physicochemical Properties

Poly(e-caprolactone) are synthetic biodegradable polymers that can potentially be used as biocompatible materials for biological applications. The purpose of this work was to investigate the effect of acetylated cellulose nanocrystals isolated from corncob waste loaded into poly(e-caprolactone) matrix blend on its thermal, mechanical, morphology, and crystallinity. The acetylated cellulose nanocrystal filler with various concentrations (namely 5, 10, 15, and 20%) was mixed with poly(e-caprolactone) matrix prepared using reflux method under N2 gas flow at 120oC for 10 min. Subsequently, the samples was characterized by thermal gravimetric analysis, DSC, tensile, Fourier transform infrared spectroscopy, tunneling electron microscope, SEM, and XRD to determine the thermal, mechanical, functional group, particle size, morphology, and crystallinity, respectively. Thermal gravimetric analysis and DSC analysis revealed that the thermal stability of poly(e-caprolactone) improved and the degree of crystallinity gradually increased with the addition of 10% acetylated cellulose nanocrystals, hence resulting in a higher Young's modulus. Fourier transform infrared spectroscopy results demonstrate that acetylated cellulose nanocrystal was successfully incorporated into poly(e-caprolactone) with an additional OH group. In addition, the particle size of 32 nm for acetylated cellulose nanocrystal and the formation of agglomeration was present based on TEM analysis, thus suggesting that acetylated cellulose nanocrystal was compatible as a reinforcing filler in the poly(e-caprolactone) matrix. SEM and XRD analysis suggests that the morphology was relatively smooth and higher crystallinity was achieved. The results of this research demonstrated the good feasibility of poly(e-caprolactone)/acetylated cellulose nanocrystal nanocomposites with improved thermal, mechanical, and physicochemical properties that were successfully prepared using simple and low-cost acetylated cellulose nanocrystal as a filler material.

Study of The Variation of Activating Agents on Specific Capacitance Values on The Synthesis of Supercapacitor Electrodes Based on Pepper Peel Waste

The by-product of pepper production in Bangka Belitung is the waste of pepper skin. This waste tends to be untapped and thrown away so that it can disrupt the environmental ecosystem. One of the efforts to utilize pepper skin waste is processing it into activated carbon as the base material for supercapacitor electrodes. The initial stage of the synthesis was carried out by a pre-carbonization process on a sample of dry and clean pepper peel waste. Furthermore, the sample is chemically activated using a chemical activator and also physical activation at a temperature of 700ºC in N2 gas flow conditions. The activated carbon resulting from the activation is then molded into electrode plates in the form of pellets with a diameter of 1 cm. The electrode plates were characterized using a scanning electron microscope-energy dispersive x-ray (SEM-EDX) to determine morphology and cyclic voltammetry (CV) to determine the specific capacitance value. SEM test results show that the electrode sample has porous morphology and CV results show that the sample activated using the KOH activator has a specific capacitance value of 15.20 F/g. These results indicate that the activated carbon synthesized from the waste of pepper peel can be used as a supercapacitor electrode material and also a solution for overcoming the negative effects of pepper skin waste.

Growth and characterization of Rhenium Nitride coatings produced by reactive magnetron sputtering

In this work, thin rhenium nitride (ReNx) films were deposited by reactive radio frequency (R. F.) magnetron sputtering on H13 steel and polished silicon substrates. To improve adhesion to the substrates, a Ti/TiN bilayer was deposited before the ReNx films. Substrate temperature, R.F. power, Ar and N2 gas flow, negative bias voltage, and working pressure were varied in the experiments when synthesizing the ReNx coatings. It was found that lower process pressure and nitrogen flow rate negatively affect the stabilization of coatings and lead to their delamination after they are extracted from the vacuum chamber. Meanwhile, higher nitrogen flow rate and work pressure increase the stability of the coatings by up to several days. Additionally, when the nitrogen flow rate and the negative bias voltage were increased, changes in the crystalline structure of the coatings were observed. However, when the work pressure and N2/Ar ratio were increased and the bias voltage was decreased, the stability of ReNx coatings continued even several weeks after their deposition. X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD) measurements validated the formation of ReN compound. The more stable deposited rhenium nitride coatings exhibited lower hardness values than the theoretical predictions for this compound, possibly due to the presence of metallic rhenium and thereby rhenium oxides, as seen in the XRD and XPS characterizations.

Sustainable valorization of sugarcane leaves for succinic acid and biochar production

The leaves of sugarcane (Saccharum officinarum) are agricultural waste that is burnt before harvesting. This project aims to find an alternative way to increase the value of sugarcane leaves and decrease air pollution by using the leaves as raw material to produce succinic acid and biochar. Reducing sugars were extracted from the leaves by H2SO4 hydrolysis. The sugars were then fermented by Yarrowia lipolytica TBRC 4417 to produce succinic acid. The solid residue was used as the raw material for biochar production by pyrolysis. The effects of pyrolysis temperature (350, 400, and 450℃) and nitrogen gas flow rate (5, 10, and 15 Lmin-1) on the specific surface area of biochar were determined. The adsorption capacity of mixed nitrogen, phosphorus, and potassium compound solution at various concentrations by biochar was also investigated. The hydrolysis condition was at 1%v/v of H2SO4, 100 gL-1 of sugarcane leaves, and hydrolysis time of 60 min. The hydrolysate yielded sugar monomers at a concentration of ca. 13.00 gL-1 of xylose and 2.00 gL-1 of glucose. The fermentation process of extracted reducing sugar from sugarcane leaves by Yarrowia lipolytica TBRC 4417 was studied at 30℃ for 84 h. with 120 rpm shaking. It was found that Yarrowia lipolytica TBRC 4417 produced succinic acid in glucose, mixed glucose and xylose, and extracted reducing sugars. The maximum succinic acid yield of 0.061 g succinic acid /g sugar consumption was obtained. For biochar production, the maximum specific surface area of 301.19 m2g-1 was found at a pyrolysis temperature of 400℃ and the N2 gas flow rate of 10 Lmin-1. The maximum adsorption capacity of the mixed solution was 28.45 wt%. The adsorption capacity of biochar was N>P>K at a total concentration of 100 mgL-1. This study demonstrates the agricultural waste's potential value as a useful feedstock for the biological generation of succinic acid and biochar.

Effect of Nitrogen Doping on Structural, Electrical, and Optical Properties of CuO Thin Films Synthesized by Radio Frequency Magnetron Sputtering for Photovoltaic Application

Effects of N-doping in CuO thin films synthesized in an ambient of Ar, O2 and N2 using a pure Cu target by radio frequency (RF) magnetron sputtering are investigated systematically with the detailed analyses on the structural, electrical, and optical properties of the thin films. A strong N-doping effect was observed on the composition, morphology, and functional properties of the resulting CuO films with the change of N2 gas flow rate (). X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of the single phase of N-doped CuO at the studied from 0 to 4 sccm. The atomic force microscopy (AFM) showed sub-rounded shape of the CuO grains. N concentrations in the N-doped CuO thin films were increased almost linearly from 1.3 × 1020 to 3.3 × 1020 cm−3 which was investigated and confirmed by SIMS. Optical absorption results of both undoped and N-doped CuO films demonstrated a direct transition at E g = 1.52 ∼ 1.56 eV with high absorption coefficient. All the undoped and N-doped CuO thin films showed p-type conductivity, and the resistivity of N-doped CuO decreases from 810 to 18 Ωcm with the increase of from 0 to 4 sccm. These results demonstrate the p-type conductivity control by N-doping, leading to the potential of N-doped CuO as an absorber material for solar cells.

Band gap reduction of (Mo+N) co-doped TiO2 nanotube arrays with a significant enhancement in visible light photo-conversion: A combination of experimental and theoretical study

The present research aimed to evaluate the effects of co-doping TiO2 nanotube aligned arrays (TNAs) with molybdenum and nitrogen on photocatalytic activity/performance under visible light irradiation. The surface morphology, electronic and optical properties of the pure and modified TNAs based on experimental characterization and theoretical calculations are reported. Both, pure and doped/modified TNAs were synthesized using a single step/low cost anodization method. Titanium sheets were immersed in ethylene glycol-based electrolytes containing NH4F and NH4F + K2MoO4 to fabricate highly ordered TNAs and Mo-doped TNAs, respectively. Mo–N-doped TNAs were fabricated by a thermal annealing process of Mo-doped samples in nitrogen environment (N2-gas flow rate of 400 cc/min) for 2hr at 520 °C. Physical/chemical characteristics, structural and photo-electrochemical/electronic properties of the photo-electrodes were observed using several techniques including, field emission scanning electron microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDX), XRD, X-ray photoelectron spectroscopy (XPS), Raman and UV–Vis spectroscopy. We further used a full potential density functional theory (DFT) method to estimate the morphological and electronic structure of the synthesized photo-anodes and also observed a good agreement between theoretical calculations and characterization results. The characterization techniques confirm that Mo and N atoms have been incorporated into the lattice of anodized TNAs and molybdenum atoms partially substituted titanium atoms in the structure of TNAs. UV–Vis DRS spectroscopy experiments and theoretical results reveal that (Mo + N) co-doping creates a positive synergic effect on the band structure of TNAs which can enhance photo-conversion activity, compared to the single Mo/N-doped TNAs samples. In presence of sacrificial agent/electrolyte (aqueous solution of Na2S/Na2SO3) and visible light irradiation, average photocurrent density of the co-doped TNAs photo-anode is 14 times greater than that of the undoped TNAs.

Minimizing film residual stress with in situ OES big data using principal component analysis of deposited AlN films by pulsed DC reactive sputtering

In this study, aluminum nitride (AlN) thin films were deposited on Si (100) and investigated on the minimum film residual stress with varying two critical deposition conditions in N2 gas flow and power. The pulsed DC reactive sputtering of aluminum targets was carried out in gas ratio of nitrogen (N2) and argon (Ar) plasma with N2:Ar ratios from 15:15 to 60:15 and power from 400 to 1000 W. According to the large-scale data of in situ optical emission spectroscopy (OES) study in connection with film microstructure information by analyzing X-ray diffraction (XRD) patterns, scanning electron microscope (SEM) micrographs, transmission electron microscope (TEM) analyses, Fourier-transform infrared spectroscopy (FTIR) spectra, and alpha-step profilers, the deposited film stress states can be highly affected by the critical processing parameters of N2 flow rate and power. In addition, the proposed value of residual stress (VRS) can be calculated by PC1-DEV (the standard deviation in the first principal component direction) method for accurate prediction of the stress states of deposited films, i.e., compressive stress or tensile stress, which will provide valuable information on residual stress characterization as the in situ monitoring tool for the AlN thin film deposition process. In summary, a methodology based on large data of OES by which principal component analysis (PCA) was utilized to reduce its dimension can be used to determine residual stress characterization from a simple measurement in situ plasma monitoring tool is suggested.

Mechanical and friction behavior of sputtered Mo–Cu–(N) coatings under various N2 gas flow using a multicomponent single alloy target

Mo–N based coatings have attracted increasing attention as protective coatings for mechanical components owing to their superior mechanical performance. In this study, ternary (binary) Mo–Cu–(N) nanocomposite coatings are prepared at various N2 gas flow rates by direct current magnetron sputtering using a multicomponent single alloy target. The microstructure, morphology, mechanical properties, and friction behavior of the coatings are characterized. The friction and wear behavior of the coatings prepared at various nitrogen gas flow rates are measured under different lubricant environments such as 5W30 with MoDTC additive and polyalphaolefin. The composition of the coatings is found to be nearly similar to that of the target regardless of the nitrogen content, but the microstructure showed significant changes. In this study, Mo–Cu–(N) nanocomposite coating obtained under N2 gas flow rate of 6 sccm exhibits the best mechanical property and friction performance under harsh environments (100 N, 150 °C) owing to the presence of hard MoxN phase with a grain size of approximately 6.43 nm and Cu phase. The extremely low friction coefficient of 0.003 is attributed to the interaction of the coating and oil/counterpart components during the friction test under the polyalphaolefin lubricant environment.

Influence of nitrogen gas over microstructural, vibrational and mechanical properties of CVD Titanium nitride (TiN) thin film coating

In this experimental investigation, the influence of different N2 gas flow rates on different properties (e.g. morphological, mechanical, etc.) of chemical vapor deposited (CVD) Titanium nitride (TiN) coatings has been discussed. The TiN coatings had been grown on Si (100) substrate at elevated temperature (1000 °C) using Titanium dioxide (TiO2) powder. SEM images reveal a dense uniform microstructure with an irregular surface pattern. The surface roughness of the coatings was found to be increased from 12.42 to 28.56 nm with an increase in flow rate. XRD results indicate a B1 NaCl crystal structure of the film with reduced crystallite size with the increasing N2 flow rate. Through the corrosion test, it has been observed that due to the variation of N2 flow rate the corrosion resistance of the films decreases with increasing N2 flow rate. The mismatch of thermal expansion co-efficient in between Si substrate and TiN thin film reduces with higher N2 flow rate. The acoustic and optic phonon mode of TiN coatings have been shifted to higher intensities with higher N2 flow rate. The mechanical properties of the film reveal that the maximum value of hardness (H) and Young's modulus (E) are 30.14 and 471.85 GPa respectively.

N2 gas flow rate dependence on the high-k LaB x N y thin film characteristics formed by RF sputtering for floating-gate memory applications

In this paper, the N2 gas flow rate dependence on the high-k LaB x N y thin film characteristics formed by RF sputtering for floating-gate memory applications was investigated. The N2 gas flow rate during the sputtering for the LaB x N y insulating layer was increased from 3 to 9 sccm with the Ar of 10 sccm for N-doped LaB6 (Metal: M)/LaB x N y (Insulator: I)/p-Si(100). Then, the N-doped LaB6/LaB x N y /N-doped LaB6/LaB x N y /p-Si(100) MIMIS diode was fabricated with LaB x N y tunnel layer and block layer formed by Ar/N2 gas flow ratio of 10/7 sccm. The equivalent oxide thickness (EOT) was decreased from 7 to 5.5 nm by increasing the N2 gas flow rate from 3 to 7 sccm. On the other hand, the LaB x N y insulating layer formed by N2 gas flow rate of 9 sccm showed EOT of 8.2 nm with crystallization. Furthermore, the memory window of 0.4 V was obtained for the MIMIS floating-gate structure utilizing the N-doped LaB6/LaB x N y stacked layer.

Salt-free and low temperature colouration of silk using He–N2 non-thermal plasma irradiation

A natural protein fibre (silk), in the form of textile, was subjected to a non-thermal plasma irradiation in a mixture of helium/nitrogen (He–N2) gases by varying the nitrogen (N2) gas flow rates at atmospheric pressure. After 4 min He–N2 plasma irradiation, the silk fabric was found to be more hydrophilic in nature in terms of decrease in time of water absorbency. A similar improvement was also noticed with an increase in both the plasma irradiation time and N2 gas flow rate. The scanning electron micrographs (SEM) of the treated samples depicted the etching of fibre surface and occurrence of micro-pits and craters. The energy dispersive X-ray (EDX) elemental analysis depicted maximum 2.2% and 2.9% increase in oxygen (O2) and nitrogen (N2), respectively owing to plasma-induced chemical change in the silk protein fibre. Mass spectroscopy results also exhibited an improvement in amine, amide, imine and other polar groups in the plasma irradiated samples, which caused them to be dyeable with acid dye without usage of salt, even at a much lower temperatures of 40 °C and 60 °C compared to conventionally used 90 °C. The rate of dyeing in the plasma pre-irradiated silk was found to improve more than 50% and 30% compared to that of the untreated silk fabric dyed at 40 °C and 60 °C, respectively. The improvements in dye absorption, dye-fixation, and colour strength were measured in details with variable gas flow rates and correlated with the changes in surface physico-chemical properties of silk polymer. It is postulated that the enhancement in surface roughness along with formation of hydrophilic groups on the fibre surface contributed towards the observed improvements. In the plasma treated dyed samples, colour stability towards the washing, rubbing and light exposure was 1–2 grades higher as compared to that in case of untreated sample. The proposed low-temperature and salt-free process will economise the cost of colouration of silk fabric, besides reducing the effluent load.

Physics and chemical activation to produce activated carbon from empty palm oil bunches waste

This research was conducted by laboratory-scale trials to make activated carbon from empty oil palm bunches. Empty bunches were palm oil processing industrial waste. This research was an effort to optimize waste management. Empty palm oil bunches were studied to become carbon active. Activated carbon is needed to meet the needs of the food industry and non-food industries. This research aimed to determine the appropriate method, optimal operating condition, and get the specification of standard carbon active. Making activated carbon was carried out by multiple activations; chemical and physical. The feed carbonation process was conducted at 400° C for 4 hours with N2 gas flow. After the charcoal is formed, chemical activation is carried out using an H3PO4 activator with a concentration of 9-15% wt. Physical activity was conducted by heating the activated carbon method in 700°C for an hour. The result of the study showed that multiple activations produced activated carbon, and the quality filled the standard. H3PO4 concentration of 13% was the most appropriate concentration to provide activated carbon with the best quality. The best quality activated carbon, which has produced of this research has complied with Indonesian National Standards 06-3730-1995 with parameters: 3% moisture content, 3.92% ash content, 0.7% volatile matter, 95.38% bonded carbon, iodine number 945.47 mg / g, and surface area of 272.9 m2/g.

Ceviz kabuğundan karbon dioksit kullanılarak aktif karbon üretimi ve metilen mavisi adsorpsiyonu.

In this study, activated carbon with strong adsorption property was synthesized from lignocellulosic structured walnut shell. Active carbon synthesis was realized in two stages: carbonization and physical activation. Carbonization was carried out at 8 different temperatures (300-1000°C), 500 ml/min N2 gas flow and 10°C/min heating rate for 1 hour. Activation was done at 2 different temperatures (800- 900 °C) at 100 ml/min CO2 gas flow for 1 hour. Characterization of activated carbons was carried out and their adsorption capacities were examined with methylene blue. The surface areas of the activated carbons were investigated by BET analysis and the surface areas ranged from 652,22 to 56,79 m2/g. Amounts of micro and mesopores in these surface areas were calculated. Besides, SEM analysis indicates the porous structure and XRD analysis confirms that the structure is amorphous. Methylene blue adsorption was performed in the aqueous phase and the capacities of the activated carbons were calculated. The methylene blue adsorption capacity of activated carbons varies between 174,81-15,96 mg/g.