Mercury Porosimetry Research Articles

Evolution of pore structure during microwave freeze-drying of Chinese yam

In order to reduce the energy consumption of freeze drying (FD), microwave freeze drying (MFD) can be used to dry Chinese yam. Porosity is a critical factor influencing transport mechanism, and can be considered as an important index to reflect the changes of structure of MFD foods. In this study, the changes of pore structure during the process of MFD Chinese yam were investigated by SEM and mercury porosimetry. The results showed that some closed pores could transform to open pores in drying process, and the open porosity showed a rising trend throughout the drying process. The pore size distribution range was about 10 nm to 106 nm throughout the drying process. In the early stage of drying, the pore size was mainly in the range of 10-104 nm, and then the pore size and the number of pores reduced. In the middle and late drying stages, the size of large pores increased again. Keywords: microstructure, microwave freeze drying, porosity DOI: 10.25165/j.ijabe.20181106.4250 Citation: Duan L L, Duan X, Ren G Y. Evolution of pore structure during microwave freeze-drying of Chinese yam. Int J Agric & Biol Eng, 2018; 11(6): 208–212.

Avaliação da eficácia de hidrofugantes e antigraffiti no Arenito Itararé

No patrimônio pétreo, a rocha está exposta aos efeitos do intemperismo. Para postergar esse processo, existem produtos de tratamento e proteção, os quais devem ser testados e aprovados, pois podem danificar mais o patrimônio do que o próprio intemperismo se os produtos não forem compatíveis com a rocha. O Theatro Municipal de São Paulo, uma importante edificação do Centro Velho da cidade de São Paulo, possui o Arenito Itararé em sua fachada frontal. Essa é uma rocha muito frágil devido à presença de esmectita em sua composição. Esse mineral se degrada muito facilmente em presença de água. Visando estudar um meio de proteger essa rocha contra a ação da água, dois hidrofugantes (siloxano — H1 — e propil siliconato oligomérico — H2) foram testados. Outro problema que atinge os centros urbanos é o vandalismo por graffiti/pichação. Como essa é uma rocha porosa, a limpeza desse tipo de ação não é totalmente efetiva e os produtos utilizados deixam resíduos que prejudicam a durabilidade da pedra. Para proteger a rocha da pichação, também foi testado um antigraffiti (AG). Para avaliar a eficiência desses produtos, foram realizados ensaios de capilaridade, tubo de Karsten, medida do ângulo de contato, microscopia eletrônica de varredura, porosimetria de mercúrio, ciclos de saturação e secagem, velocidade de ondas ultrassônicas, espectrofotometria e profundidade de penetração. Os hidrofugantes mostraram comportamentos similares, entretanto o H1 diminuiu a porosidade da rocha e não polimerizou completamente. O antigrafitti escureceu a rocha e mudou a distribuição do tamanho dos poros.

On the effect of mesoporosity of FAU Y zeolites in the liquid-phase catalysis

The porosity and acidity of three commercial FAU Y zeolites (including the original HY-2.6 and dealuminated HY-15/-30 zeolites) were studied comprehensively using nitrogen (N2) physisorption, and mercury (Hg) porosimetry, ammonia temperature-programmed desorption (NH3-TPD) and pyridine Fourier transform infrared (pyridine-IR) analyses. The combined N2 physisorption and Hg porosimetry is a useful tool to evaluate the hierarchical mesoporosity in the dealuminated samples, revealing that HY-15 and HY-30 possess >50% open mesoporosity in the mesopores range of 5–10 nm. The acidity of the dealuminated Y zeolites has been reduced significantly in comparison to that of the original HY-2.6, e.g. Bronsted acidity decreased by ca. 69 folds by dealuminating HY-2.6 to HY-30. Catalytic results of Fischer esterification of methanol with carboxylic acids and aldol condensation of benzaldehyde with 1-heptanal have evidenced that the critical role of mesoporosity of the dealuminated Y zeolites in liquid-phase reactions. For example, in the esterification of lauric acid with methanol, HY-15 and HY-30 with hierarchical mesopores showed better catalytic activity (i.e. conversion of lauric acid: 7.9% and 24.5%, respectively) than HY-2.6 (4.0%). The analysis of the catalytic results along with the acidic property suggests that the acidity is less influential than the porosity of zeolite catalysts. Results from this study allow us to explain the origin of the high activity of zeolites with mesoporosity in the liquid-phase catalysis.

Freezing–Thawing Behavior of Lime Treated Fine–grained Soil

This research study was carried out to investigate the impact of freeze-thaw cycles on the mechanical and the mineralogical properties of lime treated fine-grained soil. The unconfined compressive strength, wave velocity, volume change, water content, pH and electrical conductivity values were determined during freeze-thaw cycles. Furthermore, Mercury porosimetry and X-ray diffraction tests were carry out to determine changes at microscopic level. The soil used in this study was taken at a site near Jossigny region in eastern part of Paris–France. The soil samples were treated with optimum lime percent 3% depending on the pH method, then cured for 28 days at 20 °C. The soil samples were subjected to 12 cycles of freeze-thaw following ASTM procedure.    The result referred that, natural soil exhibit no strength resistance against freeze-thaw cycles and failed during the first hours of freeze-thaw cycles. Analyses indicated that freeze-thaw cycles reduce the unconfined compressive strength of all the tested samples. Moreover, water content during the applied cycles increases and induces significant volume changes. During freeze-thaw cycles, the cracks propagation which caused by the formation of ice lenses in the pores of lime treated soil samples were consider to have significant. The changes in the micro-structural and mineralogical properties reduce the durability  of the lime treated soil samples when subjected to freeze-thaw cycles.

Hydrothermal carbonization characteristics of sewage sludge and lignocellulosic biomass. A comparative study

This study evaluates and compares the responses of two kinds of lignocellulosic biomass (pine and acacia) and sewage sludge to their hydrothermal carbonization treatment. All materials were subjected to HTC processes in an aqueous environment at 200 °C for 4 h with a 1:8 biomass to water ratio, using a Zipperclave Stirred Reactor. The physical, chemical analyses and, additionally, fibre, mercury porosimetry analyses and optical microscope images applied to both raw materials and to hydrochars, proved that HTC enhances the energy related properties of lignocellulosic biomass. Whereas, for sewage sludge, the HTC effect is negligible, because most of the carbon is transferred to the HTC liquid phase, confirmed by high COD and high ash content in the sewage sludge hydrochar. Subsequently, the thermo-chemical conversion kinetics of the raw and HTC materials were examined in the TGA analyser through nonisothermal runs. Finally, kinetics analyses were performed by two methods based on the TGA results. The estimated apparent activation energy values obtained by the Coats & Redfern method were higher than those given by the Arrhenius method, which also gave almost similar values for all samples, shedding doubt on the accuracy of this method for the current experiments. The Coats & Redfern analysis gave activation energy values which were lower by one half for sewage sludge hydrochars compared to lignocellulosic hydrochars. This indicates the potential of the HTC process for generating sewage sludge hydrochars suitable for co-combustion or co-gasification with other biomass solid fuels.

Removal of Cr(VI) from aqueous solution using functionalized poly(GMA-co-EGDMA)-graft-poly(allylamine)

To remove Cr(VI) from aqueous solution, a macroporous poly glycidyl methacrylate-co- ethylene glycol dimethacrylate (poly(GMA-co-EGDMA)) adsorbent was synthesized by radical suspension copolymerization. Allylamine was used to open the epoxy ring of the prepared copolymer, then the radical polymerization of the grafted allylamine was performed, and as the last step, methyl isothiocyanate (MITC) was reacted with the crosslinked graft copolymers to introduce the thiourea groups. The introduced amine and thiourea functional groups enabled the effective removal of Cr(VI). The polymer was analyzed by FT-IR spectroscopy, FE-SEM, and mercury porosimetry, and the chemical structure, surface morphology and pore characteristics of the polymer were confirmed. The pH of the Cr(VI) solution strongly affected the performance of the adsorbent, and the best removal efficiency was obtained at pH 2. In the kinetic studies, the qe value determined from the pseudo-second-order model was similar to the experimental qe value, and this model showed the best correlation. The isotherm data were better fit by the Langmuir adsorption isotherm model than the Freundlich isotherm model, and the maximum adsorption capacity was 166.24 mg/g.

Microporous activated carbon electrode derived from date stone without use of binder for capacitive deionization application

Microporous activated carbon pellets have been prepared from date stone without the use of a binder. These pellets were tested as electrodes for capacitive deionization. The activation process involved two steps. First, a pyrolysis of the date stone was conducted to a temperature of 1000 °C under nitrogen flow. Then, the obtained carbon monoliths were physically activated at 900 °C under CO2 flow. Elemental analysis, BET, SEM, mercury porosimetry, conductivity measurement and electrochemical performance testing carried out to characterize the structure and the properties of activated carbon pellets. The activated carbon exhibited predominant microporosity with a specific surface area of 896 m2 g−1 which leads to the highest specific capacitance 270.90 F/g. The performance of activated carbon electrode at 900 °C in capacitive deionization (CDI) test was also examined.

Influence of coke structure on coke quality using image analysis method

The quality of coke affects the performance of the blast furnace, factors affecting coke quality include coal properties, coal charge granulometry and carbonization conditions. The coke properties include the size analysis, cold strength (Micum Indices-M40, M10) and hot strength (Coke Reactivity Index-CRI, Coke Strength after Reaction-CSR) properties and structural properties such as coke structure and texture. Structural properties comprise the porosity, pore-cell wall thickness and pore sizes, while textures consist of the carbon forms in the coke. In present work, advanced method such as image analysis method was used to interpret coke microstructure. Conventional methods such as determination of coke porosity by measurement of real and apparent density and mercury porosimetry have a number of limitations. Coke size, magnification, number of image frames captured, process of pellet preparations and coke properties such as M40, M10, CRI and CSR (low, medium and high values) were taken as variables for experimental purposes. The coke structure parameters such as porosity, length, perimeter, breadth, roundness, pore-wall thickness and pore size distribution of the pores were determined by image analysis method. This method provided average porosity in addition to pore-wall thickness and pore-size distribution. The pore wall thickness measurement by image analysis method provided significant correlations with M40, CRI and CSR values. This explained the usability of image analysis for coke structure measurement.

Effect of preparation conditions on gas permeability and sealing efficiency of graphite foil

Nitrogen permeability of graphite foil (GF) based on expandable graphite with different oxidation degrees was measured. Expandable graphite was obtained by the chemical interaction of graphite and nitric acid with the formation of graphite nitrate of II, III, IV stages and by the electrochemical oxidation of graphite in HNO3 solution followed by water washing. The expandable graphite samples were heat-treated at 800 °C with the formation of exfoliated graphite followed by pressing the exfoliated graphite into GF. The samples of exfoliated graphite and graphite foil were investigated by XRD, SEM, Raman spectroscopy and mercury porosimetry methods. GF nitrogen permeance decreases from 19.7 × 10−10 to 6.7 × 10−10 mol m−2 s−1 Pa−1 with decreasing a stage number of graphite nitrate from IV to II. Gas permeance of GF based on electrochemical expandable graphite decreases by an order of magnitude up to 0.2 × 10−10 mol m−2 s−1 Pa−1 in comparison with GF based on graphite nitrate of II stage. Thus, it is possible to produce the graphite foil material with a wide range of permeability and, respectively, the different sealing efficiency by varying the oxidation degree of the initial graphite matrix in the step of obtaining graphite intercalation compounds and expandable graphite.

Methane partial oxidation over porous nickel monoliths: The effects of NiO-MgO loading on microstructural parameters and hot-spot temperature

Developments of highly efficient catalysts for hydrocarbon fuel conversion have a critical importance for the solid oxide fuel cell (SOFC) technology and hydrogen production. In this work, a series of catalytic monoliths made of porous Ni ribbons with various NiO-MgO loadings were prepared via impregnation with the metal acetates and calcination. The catalysts were tested for the partial oxidation of methane under adiabatic conditions without inlet flow preheating at air excess factors, O2/(2·CH4), varying in the range 0.3–0.4. When NiO-MgO loading increases, the inlet hot spot temperature was found to exhibit minima reflecting changes of the CH4 reforming rate-determining factors in the catalyst frontal layer. A model describing this unusual phenomenon in terms of the volumetric activity and gas permeability of the porous catalysts, was proposed. The model was validated using experimental results of the catalytic tests, high-resolution transmission electron microscopy and mercury porosimetry.

Evolution of mechanical properties in aerial lime mortars of traditional manufacturing, the relationship between putty and powder lime

In recent years, numerous studies have been published on the technology of industrial aerial lime mortars. These papers refer to the incidence of carbonation process and mechanical behavior in its properties as construction material, of interest for its application in Cultural Heritage conservation. Among other issues, the importance of the type of aggregate (composition and granulometry) and relation binder/water (B/W) in its properties are highlighted. There are fewer papers in which the type of lime is about, especially on the basis of its manufacturing process (traditional or industrial), on the presentation of the product (powder or putty), or referred to the different types of mortars (prepared in situ or pre-dosed). In this paper, the behavior of aerial lime mortars elaborated with traditional lime has been determined and a comparative study has been carried out with pre-dosed mortars of powder (mCL) and in putty (mSPL) lime for its application in render mortar (B) and plaster mortar (F). The control parameters have been mechanical resistances-elasticity, ultrasound velocity, carbonation process and distribution pore size and surface area by mercury porosimetry. It is concluded that the behavior of traditional lime mortars, both in putty and powder, depends on the B/W ratio, the type of aggregates and the lime content. The importance of the application of the product in the building as the behavior of the mortar is very sensitive to kneading water content it shows; aspects that define the plasticity of the mortar. It is also concluded that the carbonation of traditional lime mortars is not slow and that, under optimal dosages conditions, can be finished before 90 days. It is also verified that a higher carbonation rate does not imply better properties of the mortar in its long-term construction. The utility of ultrasound velocity test as a non-destructive test and easy to apply on building for the quality control of traditional lime mortars and its consistence values it highlights, as is a macroscopic property of easy control during the elaboration of the product.

Nitrogen-containing high surface area carbon cryogel from co-condensed phenol–urea–formaldehyde resin for CO2 capture

A cost-effective nitrogen-doped super high surface area carbon cryogel has been successfully synthesized from phenol–urea–formaldehyde (PUF) resin. Pore structure and chemical characteristics were investigated using scanning electron microscopy, Fourier transform infrared spectroscopy, element analysis, X-ray photoelectron spectrometry, mercury porosimetry and N2 adsorption–desorption. It was found that the organic cryogel with mesopores and macropores from PUF resin having a N content of 9.03 wt%, which is an ideal precursor for preparing N-doped carbon cryogels. The carbon cryogel obtained having a high apparent surface area of up to 1710 m2/g, large micropore volumes up to 0.64 cm3/g, a small average micropore width of 1.04 nm and a moderate nitrogen content of 2.08 wt%. The lab-made carbon cryogel showed good CO2/N2 sorption selectivity, 15.8:1 at 273 K and 16.4:1 at 298 K. The CO2 capture capacities as high as 5.5 mmol/g at 273 K and 4.5 mmol/g at 298 K up to 1 bar were obtained, which were among the highest compared to other commercial carbon materials.

Development of novel sericin and alginate-based biosorbents for precious metal removal from wastewater.

In this study, two novel low water-soluble sericin and alginate-based biosorbents were successfully developed for precious metal removal from wastewater: sericin and alginate particles chemically crosslinked by proantocyanidins (SAPAs) and sericin, alginate and polyvinyl alcohol particles (SAPVA). The proportions of proantocynidins (PAs) or polyvinyl alcohol (PVA) added to sericin (2.5% w/v) and alginate (2.0% w/v) blend were 0.5, 1.5, 2.5 and 3.5% w/v. Among these concentrations, particles produced with 0.5% w/v of PVA or 2.5% w/v of PAs presented the lowest water solubility percentages (3.74 ± 0.05 and 3.56 ± 0.21%, respectively) and the following metallic affinity order: AuCl4- > PdCl42- > PtCl62- > Ag+. Then, gold biosorption kinetics by SAPAs was evaluated at three gold initial concentrations (72.88, 187.12, and 273.79mg/L), and its performance was compared to activated carbon adsorbent uptake. The data modeling revealed that the process follows pseudo-first-order kinetics and is mainly controlled by external diffusion. SAPAs before and after gold biosorption (SAPAs-gold) were characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, optical microscopy, helium pycnometry, mercury porosimetry, N2 physisorption, and Fourier-transform infrared spectroscopy.

Combining Breath Figures and Supercritical Fluids To Obtain Porous Polymer Scaffolds.

Supercritical fluids technology is a clean methodology to foam polymeric materials. However, this technique provides only the formation of inner porosity, whereas the so-called skin layer is commonly observed at the polymer surface. This article describes a new method for the preparation of outer and inner porous poly(ε-caprolactone) (PCL) scaffolds by combination of supercritical CO2 (SCCO2) foaming and the breath figures technique. In the first step, experiments with a SCCO2 reactor were performed at 35–45 °C, 100–250 bar, and 1–20 min depressurization time. The effect of these parameters in the formation of inner porosity was investigated for an adequate optimization. In a late stage, to provide also surface porosity to the polymeric samples and remove the skin layer, the breath figures technique was employed. The evaluation of porosity was determined by scanning electronic microscopy, mercury porosimetry, and micro X-ray computerized tomography scanning processing the images obtained with the ImageJ software. The results of this study using these two complementary techniques showed the existence of interconnectivity between inner and outer porosity of the samples. Furthermore, thermal transitions and crystallinity of the PCL samples have been analyzed by differential scanning calorimetry. Finally, a preliminary biological evaluation of the resulting scaffolds with mouse endothelial cells (C166-GFP) was performed to assess their biocompatibility and cellular viability.

Synthesis of carbon nanotube on stainless steel microfibrous composite—Comparison of direct and indirect growth and its application in fixed bed m-cresol adsorption

Two types of novel carbon nanotube (CNT) integrated stainless steel microfibrous (SSMF) composites were prepared through a combined wet lay-up papermaking, sintering and thermal chemical vapor deposition (CVD) process. Preparation methods with (indirect growth) and without (direct growth) the pretreatment using Fe-Mo/Al2O3 catalysts were applied to grow CNTs on SSMF support (SSMF-CNT and SSMF-CCNT, respectively). The composites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), N2 adsorption–desorption, mercury porosimetry, X-ray photoelectron spectroscopy (XPS) and Raman spectra. Results show that CNTs are successfully synthesized onto the support by both methods. In SSMF-CNT, CNTs grow on the surface of stainless steel microfibers while in SSMF-CCNT, CNTs grow on the surface of microfibers as well as in the network structure. The textures of CNTs in two composites are also quite different. CNTs on SSMF-CNT show better degree of graphitization than CNTs on SSMF-CCNT. Finally, fixed bed adsorption experiments of m-cresol were carried out to compare the adsorption efficiency of fixed bed filled with individual CNT particles and structured fixed bed filled with both CNT particles and CNT-microfibrous composites. Results have shown that the structured fixed beds with CNT-microfibrous composite show a smaller m-cresol adsorption capacity but lower pressure drop and enhanced mass transfer efficiency compared with the individual CNT particle bed. Comparison between SSMF-CNT and SSMF-CCNT shows that SSMF-CNT shows a higher mass transfer efficiency and utilization efficiency than SSMF-CCNT due to different growth forms and texture properties, indicating that direct method is more suitable for the preparation of CNT-microfibrous composites for pollutant removal in waste water.

Geological models and controlling factors of gas content in marine–terrigenous shale in the Southern Qinshui Basin, China

Geological prediction models for gas content in marine–terrigenous shale under the effects of reservoir characteristics and in situ geological conditions, were established using methane isothermal adsorption, high temperature/pressure methane isothermal adsorption, total organic carbon, X-ray diffraction, mercury porosimetry, porosity in net confining stress, and field desorption methods. Results indicated that the adsorption capacity of marine–terrigenous shale has a linearly positive correlation with total organic carbon content and maturity. Clay and quartz minerals are the two main components of inorganic minerals in marine–terrigenous shale, with an average content of 54.3% and 36.9%, respectively. Adsorption capacity of marine–terrigenous shale is slightly positive correlated with clay content, while it exponentially decreases with increasing quartz content. The effects of in situ temperature and reservoir pressure on adsorption capacity in marine–terrigenous shale are also significant. The adsorption capacity of marine–terrigenous shale shows a clear decreasing trend as temperature increases, while it increases with increasing reservoir pressure. The porosity of marine–terrigenous shale is characterized by highly stress-sensitive, decreasing exponentially with increasing effective stress, which results in a more complex occurrence of free gas in deep shale reservoirs. In addition, gas saturation for the shale samples was calculated based on the results of field desorption, after which geological prediction models of total gas, adsorbed gas, and free gas were established while considering the coupled effects. Adsorbed gas, free gas, and total gas content all initially increase as burial depth increases, and then eventually decrease. Adsorbed gas content and free gas content have a positive correlation with total organic carbon content and porosity, indicating that the total gas content at different burial depths is mainly controlled by the total organic carbon content and porosity.

Post-mortem analysis of alumina-magnesia-carbon refractory bricks used in steelmaking ladles

Post-mortem studies in secondary steelmaking ladles are an important way to determine the factors related to Alumina-Magnesia-Carbon (AMC) refractory corrosion. AMC refractory bricks installed in the impact zone of a steelmaking ladle bottom were analyzed after 100 castings. X-ray diffraction, X-ray fluorescence chemical analysis, reflected optical light microscopy, scanning electron microscopy, energy dispersive X-ray spectrometry, density and porosity measurements, and mercury porosimetry were used to analyze the chemical and physical characteristics of the slag, the unused refractory and the slag+steel attacked bricks. The corrosion process produced a specific microstructure characterized by: i) a thick discontinuous slag layer composed by secondary spinel+steel+liquid; ii) a thick dense, cracked, and continuous layer consisting of calcium aluminates+steel+liquid at the slag/refractory interface; iii) next to this layer, a wide densified layer with a uniform microstructure in which corundum aggregates and spinel crystals were linked together by elongated CaAl12O19 crystals.The formation of these reaction layers constituted a barrier that effectively suppressed the massive slag penetration and surely reduced the wear rate. Thermodynamic calculations based on simplified and complex condensed phase equilibrium diagrams, were used to further understanding of the corrosion mechanism.

Use of micro-computed tomography imaging and porosity measurements as indicators of collagen preservation in archaeological bone

Collagen isolated from archaeological bone is a common material for radiocarbon dating, stable isotope analysis, and zooarchaeology by mass spectrometry (ZooMS). However, not all bones contain extant collagen, leading to unnecessary destruction of unproductive bones and wasted laboratory time and resources. An aim of this research is to study bone diagenesis, particularly collagen destruction, in an effort to develop a minimally destructive method for identifying bones with high collagen content. In a multi-method study of variably preserved bones from Etton, Cambridgeshire, UK, we examined material properties of Neolithic cattle and sheep bones including porosity, surface area, and elemental composition. Micro-computed tomography (microCT) is an imaging technique that furnishes three-dimensional images of mineralized materials such as bone. Cortical bone porosity, the percentage of total bone volume consisting of empty space as calculated using microCT, can act as a proxy for bone collagen preservation. In general, bones with high cortical porosity are unlikely to contain sufficient collagen for further analysis. Bones with apparently low cortical porosity have a more varied range of collagen preservation. Bone samples with low porosity and no extant collagen often contain micropores with a diameter of 10 nm or less that cannot be seen in microCT images but are apparent in pore size distributions measured by mercury porosimetry, and indicated by high surface areas measured by nitrogen adsorption. Furthermore, a re-evaluation of light-induced breakdown spectroscopy data from this same assemblage confirms that ratios of calcium to fluorine may likewise indicate the state of diagenesis.

Deep desulfurization of natural gas by a commercial ZnO adsorbent: A mathematical study for fixed-bed reactors

Natural gas deep desulfurization process by zinc oxide adsorbent is an example of noncatalytic gas-solid reactions, which plays a crucial role in petrochemical and refinery industries. In this paper, it was tried to model the desulfurization process using grain model. In order to analyze the adsorbent properties, a commercial sample was tested by BET, XRF, SEM and, mercury porosimetry. The results of the numerical model were validated against the experimental data from a packed-bed reactor. The breakthrough time of the model was estimated with less than 5% error, indicating a good correspondence with experiments.The concentration profiles along the bed and inside the pellets have been also explored under the industrial conditions. The predicted breakthrough time for the commercial adsorbent has been estimated around 215 days. To identify the influential process parameters on the lifetime of the adsorbent bed, and degree of the bed conversion, the sensitivity analysis was performed in terms of natural gas flow rate and hydrogen sulfide concentration. Interestingly, the obtained results indicated that increasing the unit capacity by 10%, will decline the breakthrough time by 30 days. Furthermore, varying the H2S content of the inlet gas by 25% will shorten the breakthrough time of the commercial sorbent by 60 days.

Study of Polypyrrole/Graphene Oxide Nanocomposite Structural and Morphological Changes Including Porosity

Polypyrrole/graphene oxide (PPy/GO) nanocomposite films were electrochemically synthesized to study their structural features. For this purpose, pyrrole monomer was exposed to oxidation in an aqueous dilute solution containing definite amounts of GO and a dopant electrolyte. Potentiostatic electropolymerization was carried out and the current-time curves were obtained for each electrodeposition test. Accordingly, a number of appropriate characterization analyses such as mercury porosimetry, TGA, SEM, XRD, Raman and FTIR spectroscopies were performed in order to investigate the composition and structure of the films. In this regard, factors such as incorporation of GO in the polymer matrix, porous layer structure and the thickness of the films were determined. The results showed that GO concentration could influence on both film thickness and its porous structure. Also, it was observed that the main factor controlling the film thickness and morphology is the potential applied.