Physical Adsorption Type Research Articles

Electrochemical and theoretical evaluation of dihydro-benzoimidazoquinazolines as corrosion inhibitors for API X-120 steel in acid medium

In this paper, the corrosion inhibition of three dihydro-benzoimidazoquinazolines, namely 2´,6´diFDHBIQz 1, 2Br2´,6´diFDHBIQz 2 and 2,4diBr2´,6´diFDHBIQz 3 was determined for an API 5 L X120 steel in 0.5 M HCl. Electrochemical techniques such as Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization curves were used obtaining inhibition efficiencies greater than 90 %. In addition to this, Quantum chemical calculations using the DFT technique was used to correlate the inhibitors efficiency and their electronic properties. Results have shown that the three organic compounds are good, mixed type of corrosion inhibitors, with an efficiency that increased with their concentration but decreased with the temperature. The inhibitor efficiency decreased in the order 2´,6´diFDHBIQz 1 > 2Br2´,6´diFDHBIQz 2 > 2,4diBr2´,6´diFDHBIQz 3. All of them were adsorbed on to the steel surface following a Langmuir type of adsorption isotherm, however 2´,6´diFDHBIQz 1and 2Br2´,6´diFDHBIQz were adsorbed in a mixed chemical and physical way dominated by a physical type of adsorption, whereas 2,4diBr2´,6´diFDHBIQz 3 was physically adsorbed. Quantum chemical results revealed that 2´,6´diFDHBIQz 1 was the most efficient because it had the highest HOMO energy.

A MIXTURE OF ACACIA BARK EXTRACT (Acacia mangium Willd) AND POTASSIUM IODIDE AS A CORROSION INHIBITOR IN SULFURIC ACID SOLUTION

Corrosion is a decrease in the quality of a metal material caused by a reaction with the environment. Corrosion cannot be eliminated, but corrosion can be slowed down in several ways by adding corrosion inhibitors and synergistic effects. Acacia bark extract (Acacia mangium Willd) with the addition of 0.02 M KI has the potential as a corrosion inhibitor for steel because it contains secondary metabolites, so it can provide a synergistic effect and increase the value of inhibition efficiency on steel. This research aimed to analyze the effect of a mixture of acacia bark extracts (Acacia mangium Willd) with the addition of KI on inhibition efficiency corrosion of mild steel in sulfuric acid media. The method used in this study is the method of weight loss, adsorption isotherms, and thermodynamic parameters, which were carried out by varying the concentration of acacia bark extract and the immersion temperature of the steel. To strengthen the research results, characterization was carried out using FTIR and SEM. The results showed that the corrosion rate of mild steel immersed in 0.75 M H2SO4 corrosive medium with the addition of 0.02 M KI increased with increasing immersion temperature. These results are reinforced by the results of FTIR and SEM analysis which show that there is an interaction between mild steel and acacia bark extract (Acacia mangium Willd) and KI 0.02 M. Based on the thermodynamic parameters, the resulting values of ∆Hads, ∆Gads, and ∆Sads show that the adsorption process of acacia bark extract (Acacia mangium Willd) in corrosive medium H2SO4 0.75 M with the addition of 0.02 M KI took place spontaneously, showing the type of physical adsorption, adsorbed stable, the adsorption process was exothermic and the degree of irregularity in the adsorption process. The inhibition efficiency of acacia bark extract (Acacia mangium Willd) with the addition of 0.02 M KI was highest at 60 °C with an extract concentration of 2.5 g/L of 81%. The higher the immersion temperature, the greater the resulting synergistic effect

Specifically designed 10-Fe1Mn1-USY hydrophobicity material for acetone adsorption under high humidity condition

Acetone is a solvent used in many laboratories and factories. Serious problems will occur when it is exposed to the environment. Therefore, a new design hydrophobicity bimetallic metal material (10-Fe1Mn1-USY) was prepared for acetone adsorption under conditions of high humidity. Hydrophobic Y type zeolite was used to prepare bimetallic metal materials and the effect of different operating parameters (including different material, humidity, temperature, pollutant concentration, residence time, and regeneration) on the efficiency of acetone treatment was examined. Isothermal adsorption model, kinetics and thermodynamic model analysis were also used to establish the reaction mechanism. The 10-Fe1Mn1-USY material has good adsorption capacity (133 mg g−1) for acetone under a relative humidity of 50%. The main factors affecting the adsorption capacity are the contact angle, hydrophobicity, specific surface area, and Si/Al of the material. The isothermal adsorption and the kinetic adsorption behavior of 10-Fe1Mn1-USY material for acetone are more suitable for the Temkin isotherm adsorption model and the pseudo-first-order kinetic model. The adsorption of acetone by 10-Fe1Mn1-USY material is dominated by intra-particle diffusion. According to the thermodynamic analysis results, the adsorption behavior of 10-Fe1Mn1-USY material for acetone is a type of physical adsorption, and a spontaneous and non-sequential reaction.

Uso del extracto de litchi chinensis como inhibidor de la corrosión del aluminio 2024-T3 en 3.5% NaCl

The corrosion inhibition of AA2024-T3 Aluminium alloy in 3.5 % NaCl solution by using Litchi chinensis seed ethanolic extract has been evaluated by using potentiodynamic polarization curves, linear polarization resistance and electrochemical impedance spectroscopy tests. Results have shown that the extract was a good corrosion inhibitor with an efficiency that increased with its concentration. Corrosion and passivation current density values were decreased indicating that the extract behaves as an anodic type of corrosion inhibitor. Inhibitor was adsorbed on to the metal surface in a combination of physical and chemical, dominated by a physical type of adsorption following a Langmuir adsorption isotherm. Corrosion rate was decreased due to the formation of a protective corrosion products layer which blocked further corrosion of metal by electrolyte.

Adsorption behavior of carbonic acid on γ‐dicalcium silicate surface from molecular simulations

AbstractThis paper aims to investigate the adsorption of carbonic acid and water molecules on the (010) surface of γ‐dicalcium silicate (γ‐C2S) at an atomic scale using density functional theory (DFT) and ab initio molecular dynamics. It provides novel insights into the mechanism of carbonation on the surface of γ‐C2S. The electrons transfer and interfacial reactions between the carbonic acid (H2CO3) molecule and the γ‐C2S surface are characterized by adsorption configuration, bond order, electron density difference, and partial density of states. There exist strong interactions between H2CO3 and γ‐C2S surface, including two types of chemical adsorption and one type of physical adsorption. This work confirms that water in the carbonation of γ‐C2S is to react with CO2 to provide the reactants, and protons transfer of the carbonic acid molecule plays a crucial role in the carbonation process. The adsorption of the carbonic acid molecule is more favorable with respect to that of the water molecule, which may be the initial step of the carbonization of γ‐C2S.

Scavenging malachite green dye from aqueous solution using durian peel based activated carbon

Physiochemical activation consists of heat treatment coupling with CO2 gasification and KOH chemical treatment were applied in preparing durian peel based activated carbon (DPAC) to remove basic dye, malachite green (MG) from aqueous solution. Several parameters namely, effect of initial MG concentration as well as contact time, solution temperature and initial solution pH were carried out in this study. Characterization study revealed that DPAC pose high BET surface area which is 886.31 m2/g and its surface was found to be mesoporous in nature with heterogeneous type of pore structures. Eight isotherms and four kinetic models were utilized and it was revealed that the adsorpttion system followed Freundlich isotherm and pseudo-first order (PFO) kinetic model. Mechanism study using intraparticle diffusion and Boyd plot confirmed that adsorption of MG onto DPAC was controlled by the film-diffusion mechanism. Thermodynamic study indicated that the adsorption system was exothermic, spontaneous, feasible and governed by physical-type of adsorption.

Use of a Metallic Complex Derived from Curcuma Longa as Green Corrosion Inhibitor for Carbon Steel in Sulfuric Acid

A tin-containing metallic complex derived from Curcuma longa, bis[1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dionato-κO,κO′]bis(butyl), has been obtained and used as a green corrosion inhibitor for carbon steel in 0.5 M sulfuric acid by using weight loss, electrochemical techniques, and the Density Functional Theory. It was found that the obtained metallic complex greatly decreases the steel corrosion rate by adsorption according to a Frumkin model in a weak, physical type of adsorption. Inhibitor efficiency increased with its concentration, and it acted as a mixed type of inhibitor. Results were supported by quantum-chemical research in order to examine the relationship between structural and electronic properties and the inhibitor efficiency.

Assessment on the Effective Green-Based Nepal Origin Plants Extract as Corrosion Inhibitor for Mild Steel in Bioethanol and its Blend

Effects of Nepal origin plant species of Vitex negundo, Catharanthus roseu, Aegle marmelos and Elaeocarpus ganitrus extracts on mild steel corrosion were explored in bioethanol (E100) and its blend (E15) in airtight condition at 25±2 °C using static immersion, inhibition efficiency and mechanism tests which were complemented with adsorption isotherms and potentiodynamic polarization studies. Corrosion resistance of the mild steel was increased with increasing 500-2000 ppm concentrations of each plant extract in E100 and E15 biofuels. Additions of V. negundo and C. roseus extract separately in both the biofuels seems to be more effective inhibition actions to prevent the mild steel corrosion than A. marmelos or E. ganitrus addition so as the corrosion rates of the mild steel in E100 and E15 are successfully lowered even than in commercial gasoline (E0). The results obtained from the corrosion rate revealed the order of the corrosion inhibition efficiency (IE) as V. negundo > C. roseus > A. marmelos > E. ganitrus. The maximum IE (IEmax) in V. negundo and C. roseus leaves was showed about 89-86% and 71-75%, respectively, at 2000 ppm concentration, in spite of the other two more plants leaf extract also used as the corrosion inhibitors for the mild steel in both E100 and E15 biofuels. The IE increased on increasing inhibitor concentration following the Langmuir and Temkin adsorption isotherms but decreased with immersion time which suggested that the corrosion inhibition mechanism is of physical type of adsorption of the leaves constituents on the mild steel surface. A. marmelos extract acted as an anodic type of inhibitor in E100 and E15, while E. ganitrus acted as mixed

Theoretical study of the adsorption of amantadine on pristine, Al-, Ga-, P-, and As-doped boron nitride nanosheets: a PBC-DFT, NBO, and QTAIM study

Nowadays, nanostructures such as nanotubes and nanosheets are widely used in industry, especially the medical industry, for drug delivery, prevention and treatment. In the present investigation, the feasibility of detecting the amantadine gas molecule onto the outer surface of pristine single layer boron nitride nanosheet, as well as its aluminum (Al)-, gallium (Ga)-, phosphorus (P)-, and arsenic (As)-doped structures, was carefully evaluated. For achieving this goal, a periodic boundary condition density functional theory level of study using the HSEH1PBE functional together with a 6-311G (d) basis set has been used. Subsequently, the B3LYP-D3, wB97XD, and M062X functionals with a 6-311G (d) basis set were also employed to consider the single point energies. Subsequently, the B3LYP-D3 (BJ)/6-31G (d) method was also used to consider the contribution of scattering interactions to energy analyzes, natural bond orbital and quantum theory of atoms in molecules and the results were compatible with the electronic properties. In this regard, the total density of states, the Wiberg bond index, natural charge, natural electron configuration, donor–acceptor natural bond orbital interactions, and the second-order perturbation energies are performed to explore the nature of the intermolecular interactions. All of the calculations and analyses denote that by adsorbing of the amantadine molecule onto the surface of pristine boron nitride nanosheet, the adsorption is of the type of physical adsorption and van der Waals interactions. Among the doped nanotubes, gallium-doped nanotube has a very high adsorption energy compared to other elements, and is expected to be chemically adsorbed in this case and appears to be a suitable drug delivery option.

Magnetic mesoporous silica material (Fe3O4@mSiO2) as adsorbent and delivery system for ciprofloxacin drug

Magnetic mesoporous materials covered with mesoporous silica shells (Fe3O4@mSiO2) are the most promising material, which is fulfilling many applications especially for adsorption and delivering drugs system. The present research involves the preparation of magnetic nanoparticles Fe3O4 and mesoporous silica mSiO2 as coreshell materials using sol–gel method in the presence of amid propyl betaine surfactant as template. The surface texture, morphology and particle and crystalline size of the prepared adsorbent were characterized using SEM, TEM, XRD, and nitrogen adsorption–desorption techniques. The results show that the prepared adsorbent has surface area equal to 1670 m2/g, mesopores in range 2-10 nm with a high degree of ordering of the porous structure and has a crystalline size equal to 30.16 nm. The adsorption behavior of Ciprofloxacin drug from aqueous systems onto the adsorbent has been studied using a batch experiments method. The equilibrium of the process at temperature 293K was achieved within 120 min and 0.06 g of adsorbent dose. Adsorption isotherms were fitted with the Langmuir, Freundlich, Temkin, and Dubinin –Radushkevich models and the results show the Langmuir and Temkin model was best fitted, and the adsorption process is physical adsorption type. The kinetic data were analyzed and found to match well with pseudo-second order kinetic model. Ciprofloxacin drug loading and capacity of release of the Fe3O4@mSiO2 carrier was also studied.

Carbon Dioxide Adsorption on Porous and Functionalized Activated Carbon Fibers

Polyacrylonitrile-based activated carbon fibers (ACFs), modified using potassium hydroxide (KOH) or tetraethylenepentamine (TEPA), were investigated for carbon dioxide (CO2) adsorption, which is one of the promising alleviation approaches for global warming. The CO2 adsorption isotherms were measured, and the values of isosteric heat of adsorption were calculated. The results showed that the KOH-modified ACFs exhibited a great deal of pore volume, and a specific surface area of 1565 m2/g was obtained. KOH activation made nitrogen atoms easily able to escape from the surface of ACFs. On the other hand, the surface area and pore volume of ACFs modified with TEPA were significantly reduced, which can be attributed to the closing or blocking of micropores by the N-groups. The CO2 adsorption on the ACF samples was via exothermic reactions and was a type of physical adsorption, where the CO2 adsorption occurred on heterogeneous surfaces. The CO2 uptakes at 1 atm and 25 °C on KOH-activated ACFs reached 2.74 mmole/g. This study observed that microporosity and surface oxygen functionalities were highly associated with the CO2 uptake, implying the existence of O-C coordination, accompanied with physical adsorption. Well cyclability of the adsorbents for CO2 adsorption was observed, with a performance decay of less than 5% over up to ten adsorption-desorption cycles.

Au(CN)2]—Adsorption on a Graphite (0001) Surface: A First Principles Study

Gold is mainly present in the form of [Au(CN)2]− during the cyanide leaching process, and this [Au(CN)2]− can be adsorbed by graphite in carbonaceous gold ore resulting in preg-robbing gold. In order to clarify the adsorption mechanism between the [Au(CN)2]− and graphite, the interaction between the [Au(CN)2]− and graphite (0001) surface was studied using density functional theory (DFT). The distance between [Au(CN)2]− and graphite (0001) decreased from (4.298–4.440 Å) to (3.123–3.343 Å) after optimization, and the shape of [Au(CN)2]− and graphite (0001) obviously changed from straight to curved, which indicated that the [Au(CN)2]− had been adsorbed on the graphite (0001) surface. A partial densities of state (PDOS) analysis revealed that there was little change in the delocalization and locality of the PDOS on the graphite (0001) surface after adsorption. However, the valence bands of the Au 5d orbital, C 2p orbital, and N 2p orbital near the Fermi level moved slightly towards lower energy levels; therefore, the adsorption configuration was stable. An analysis of the Mulliken charge population indicated that the Au, N, and C in [Au(CN)2]− obtained 0.26, 0.18, 0.04 electrons after adsorption, respectively, while C(surf) lost 0.03 electrons. [Au(CN)2]− changed to a conductor from an insulator after adsorption. Taking into account the surface electrical properties of [Au(CN)2]− and graphite (0001), there was still a slight electrostatic adsorption between them. The analysis of adsorption energy, electronic structure, PDOS, electron density, Mulliken charge population, and Mulliken bond population revealed that [Au(CN)2]− could be adsorbed to the graphite (0001) surface; the adsorption was a type of physical adsorption (including electrostatic adsorption) and mainly occurred on the two C≡N. These results contributed to the understanding of the mechanisms involved in preg-robbing gold formation by graphite and the optimization of this process during cyanide leaching.

Nicotinic acid as green inhibitor for copper corrosion in 3.5 wt % NaCl solution: experimental and quantum chemical calculations

This work reports the inhibition properties of nicotinic acid (NAC) for copper protection during its applications in seawater systems such as water pipelines, shipbuilding, seawater desalination operations and heat exchange systems. The efficiency of nicotinic acid (NAC) as a copper corrosion inhibitor in 3.5 wt % NaCl solution was investigated by Tafel extrapolation and electrochemical impedance spectroscopy (EIS) methods in the temperature range from 20 to 50 °C. The corrosion parameters and the adsorption isotherms were determined from the potentiodynamic polarization curves. It was found that the inhibitory efficiency (η%) and the coverage rate (θ) increase to a maximum of 87.97 at 25 °C in 10 mM of nicotinic acid at fixed temperature but decrease as the temperature of the solution increases. Nicotinic acid acts is a purely cathodic inhibitor. Moreover, the obtained thermodynamic parameters using Langmuir model suggested a physical adsorption type. A correlation was found between the corrosion inhibition efficiency and the theoretical parameters obtained by the functional density method B3LYP/ 6-31 + G (d, p). All these results indicate that the addition of NAC in the corrosive solution significantly decreases the corrosion rate. Keywords : Nicotinic acid, copper corrosion inhibition, electrochemical impedance spectroscopy, quantum chemical calculations.

Efficient removal of Acid Green 25 dye from wastewater using activated Prunus Dulcis as biosorbent: Batch and column studies

Biosorbent synthesized from dead leaves of Prunus Dulcis with chemical activation during the synthesis was applied for the removal of Acid Green 25 dye from wastewater. The obtained biosorbent was characterized using Brunauer-Emmett-Teller analysis, Fourier transform-infrared spectroscopy and scanning electron microscopy measurements. It was demonstrated that alkali treatment during the synthesis significantly increased surface area of biosorbent from 67.205 to 426.346 m2/g. The effect of various operating parameters on dye removal was investigated in batch operation and optimum values of parameters were established as pH of 2, 14 g/L as the dose of natural biosorbent and 6 g/L as the dose of alkali treated biosorbent. Relative error values were determined to check fitting of obtained data to the different kinetic and isotherm models. It was established that pseudo-second order kinetic model and Langmuir isotherm fitted suitably to the obtained batch experimental data. Maximum biosorption capacity values were estimated as 22.68 and 50.79 mg/g for natural biosorbent and for alkali activated Prunus Dulcis, respectively. Adsorption was observed as endothermic and activation energy of 6.22 kJ/mol confirmed physical type of adsorption. Column experiments were also conducted to probe the effectiveness of biosorbent for practical applications in continuous operation. Breakthrough parameters were established by studying the effect of biosorbent height, flow rate of dye solution and initial dye concentration on the extent of dye removal. The maximum biosorption capacity under optimized conditions in the column operation was estimated as 28.57 mg/g. Thomas and Yoon-Nelson models were found to be suitably fitted to obtained column data. Reusability study carried out in batch and continuous column operations confirmed that synthesized biosorbent can be used repeatedly for dye removal from wastewater.

Nicotinamide Inhibition Properties for Copper Corrosion in 3.5% NaCl Solution: Experimental and Theorical Investigations

This work reports the inhibition properties of nicotinamide (NAM) for copper protection during its applications in seawater systems such as water pipelines, shipbuilding, seawater desalination and heat exchange systems. The efficiency of NAM as a copper corrosion inhibitor in simulated seawater (3.5% NaCl solution) was investigated by Tafel extrapolation and linear polarization methods in the temperature range from 20℃ to 50℃. The corrosion parameters and the adsorption isotherms were determined using potentiodynamic polarization techniques. It was found that the inhibition efficiency (η) and the coverage rate (θ) increase up 80% at 25℃ for nicotinamide concentration of 10 mM but decrease as the temperature of the solution increases. Moreover, the obtained thermodynamic parameters using Langmuir model suggested a physical adsorption type. A correlation was found between the corrosion inhibition efficiency and the global theoretical parameters obtained by the functional density method B3LYP/ 6-31 + G (d, p). Local parameters such as condensed Fukui functions [f(r)] and condensed local softness [s(r)] indices have also been determined to obtain a chemical insight into atoms that have a significant tendency toward donation or acceptance of whole or fraction of electrons.

Modelling the hydrophilic extraction of the bark of Eucalyptus nitens and Eucalyptus globulus: Adsorption isotherm and thermodynamic studies

Eucalyptus species have shown to have polyphenolic compounds with proven antioxidant activity. To obtain these active compounds, the basic aspects of the extractive process need to be studied. In this work, the adsorption process of polyphenols obtained from Eucalyptus nitens and Eucalyptus globulus bark was evaluated, expressed as adsorption isotherms to describe solute/solid interactions. Also, the thermodynamic parameters of the extraction process were calculated. Firstly, the extractive process was optimized by a Box-Benhken experimental design for each Eucalyptus species, maximizing the extraction yield, the total phenols content and its antioxidant capacity. Subsequently, the solute/solid interactions of the phenolic/bark system were determined at various concentrations, and temperatures; allowing even later, to model multistage extractions of phenolic compounds from bark powder. The extracted and non-extracted bark powders were morphologically (SEM) and physically (BET adsorption) characterized. The extractive process led surface changes for both species, being the BET areas similar (55m2/g) and with porous in the mesoporous range. The equilibrium data were best adjusted to Freundlich isotherm, indicating a simple modelling type, which can be used for global studies of the large-scale extractive process for the modelling of phenolic multi-extractions. Thermodynamic parameters ΔHo, ΔGo and ΔSo demonstrated an exothermic and spontaneous process with restricted movement of adsorbate molecules during adsorption, and low values of ΔGo and free adsorption energy, E, calculated from D-R model indicated a physical adsorption type for both eucalyptus species. The validation of the isotherm models presented results that are consistent with the experimental data obtained, through a multi-extraction of five stages for both species of eucalyptus.

Adsorption of NH4+-N on Chinese loess: Non-equilibrium and equilibrium investigations

NH4+-N is a crucial pollutant in landfill leachate and can be in high concentrations for a long period of time due to anaerobic condition of landfills. The adsorption properties of NH4+-N on the Chinese loess were investigated using Batch test. The influences of ammonium concentration, temperature, reaction time, slurry concentration, and pH on the adsorption process are evaluated. Adsorption kinetics and isotherm behaviors were studied by applying different models to the test data to determine the adsorption parameters. The equilibrating duration was shown to be less than 60 min. The data on adsorption kinetics can be well fitted by the pseudo-second-order kinetics model. According to the Langmuir isotherm model, the adsorption capacity of Chinese loess about NH4+-N was predicted to be 72.30 mg g−1. The uptake of NH4+-N by Chinese loess was considered to be the type of physical adsorption on the basis of D–R isotherm analysis. The optimal pH and slurry concentration are 4 and 2 g/50 ml, respectively. According to the calculated values of free energy, enthalpy and entropy change, the adsorption process is determined to be exothermic. The disorder of the system appeared lowest at temperature of 308.15 K. The predicted Gibb's free energies also indicate the adsorption process is endothermic and spontaneous. The FTIR spectrum and EDX analysis showed the adsorption process of NH4+ involves cation exchange and dissolution of calcite.

Adsorption of Methylene Blue from Aqueous Solution by AB-8 Macroreticular Resin

Study on adsorption kinetics and thermodynamics of methylene blue by AB-8 macroreticular resin was carried out through static experiments. The results showed that the adsorption rate for the solute appear to be the first order kinetics, the intraparticle diffusion is the main rate-controlling step. In the experimental temperature, thermodynamic studies indicated that methylene blue adsorption onto resin AB-8 conforms to Langmuir and Freundlich adsorption isotherm. Methylene blue adsorption quantity respectively 30 mg/L, 150 mg/L, and 300 mg/L . The adsorption enthalpy change is 40.3 kJ/moL , 39.2 kJ/moL , and 33.6 kJ/moL respectively. The uptake of salicylic acid on AB-8 macroreticular resin is a type of physical adsorption.

CHARACTERIZATION OF IMMOBILIZED LIPASE IN ALUMINOSILICATE FOR LACTOSYL PALMITATE SYNTHESIS

Whey lactose can be esterified enzymatically by using immobilized lipase. The lipase can be isolated from Rhizopus oryzae, purified and immobilized in mesoporous aluminosilica. The use of immobilized lipase has advantages, there are longer shelf life and repeatable use. It is necessary to characterize the immobilized lipase dan ester product. The aim of the research was to characterize immobilized lipase, including determination lipase adsorption type in mesoporous aluminosilicate, immobilized lipase stability during storage time, efficiency of repetitive use of immobilized lipase. The result showed that lipase adsorption in mesoporous aluminosilicate was physical adsorption type through hydrogen bound and electrostatic interaction. Immobilized lipase stability was relatively constant at storage temperature 5 °C for 25 days resulting in 98.16% of initial activity. The repetitive use of immobilized lipase showed efficient until 5 uses within activity of 50.22%. The IR spectra of lactosyl palmitate from both whey and pure lactose result showed bands at wavelength number of 3462 cm-1(OH bond), 1739 cm-1 and 1747 (C=O ester bond) 1295 cm-1 dan 1242 cm-1 (C-O ester bond). In addition, the HLB value for lactosyl palmitate (whey) 4.708 and lactosyl palmitate (pure lactose) 4.715, therefore both lactosyl palmitate is appropriate as emulgator in W/O. Keywords: immobilized lipase, aluminosilica, lactose, whey, lactosyl palmitate

コンテナ内貨物の汗ぬれ損傷に対する防止策-III : アルミニウムシートによるシリカゲル使用量の削減法

Japan depends on imports for most of agricultural products, which includes not only luxury foods but also essential ones such as wheat and soybeans. The cargo-container transportation plays an important role for the importation, but the sweat damages that occur during rapid cooling processes has been a serious problem. We made the mechanism of occurrence of the sweat damages clear by means of experiments and simulation on the containers loaded soybean, and suggested the use of the chemical or physical adsorption type silica gels, the desiccant, for a prevention of the sweat damages. However, the usage of the large amount of silica gel would be unfavorable in the cost, considered in the viewpoint of the practicality. In this paper, we investigated the reduction of the need of silica gel by partially covering the cargos with a sheet of aluminum. Only covering 55% of the cargo surface with a sheet of aluminum reduced the need of silica gel to one-tenth of the amount without covering. This result indicate that the cost for use of a silica gel and an aluminum sheet would be comparable to that for the commercial tool,