توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱The mixed matrix membranes made with zeolite and polymer
نویسنده(ها): ،
اطلاعات انتشار: همایش بین المللی ژئولیت ایران، سال
تعداد صفحات: ۹
Membrane separation processes have become one of emerging technologies during the past few decades.
Gas and liquid separation processes require a membrane with high permeability and selectivity. MMMs are
obtained by embedding a filler material such as molecular sieves and zeolites and or conductive polymer
into a polymer matrix. MMMs are expected to combine the separation properties of polymer such as
flexibility and low cost with those of zeolite such as molecular seiving action , selective adsorption ,high
mechanical strength and good thermal and chemical stability,and thus ,the resulting filler membranes can be
used on a wide range of operating condition. Some of the topics that are discussed in this review include:
1)the effect of interface morphologies on the transport properties of zeolite\polymer MMMs 2) the
polymer chain rigidification and it's effect 3) zeolite pore size 4) the amount of zeolite in MMMs 5) particle
sedimentation and agglomeration Several method for improving these factors are also suggested.<\div>

۲ZSM–5 Zeolite Membrane Preparation, A Review
نویسنده(ها): ،
اطلاعات انتشار: همایش بین المللی ژئولیت ایران، سال
تعداد صفحات: ۶
Over the last decade, much attention has been focused on the development of continuous zeolite–based
separations processes. For such purposes, the natural configuration of the zeolite material is in the form of a
thin film or membrane supported on, or deposited in, a porous substrate. ZSM–5 type zeolite membranes
have shown promise for molecular sieving applications that require high chemical and thermal stability.
ZSM–5 type zeolite membranes were prepared by template–free seeded growth method in order to minimize
defects and\or intercrystalline gaps that form during the calcination step required for template removal. In
many cases, microwave synthesis has proven to remarkably reduce the synthesis time. In addition,
microwave synthesis could also result in different membrane morphology, orientation, composition, and thus
the different permeation characteristics as compared with those synthesized by conventional heating.<\div>

۳Application of Silver Nanoparticles in the Reverse Osmosis Membrane
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
Membrane biofouling constitutes a major obstacle to the application of membrane techniques such as reverse osmosis in the production of drinking water. In this study, the thin film nanocomposite (TFN) membrane consisting of silver nanoparticles with antibacterial capability on microorganismwas devised as a novel means to reduce membrane biofouling.Silver nanoparticles were prepared by sonochemical synthesis method using poly (vinylepyrrolidone) (PVP) as stabilizer and methaphenylenediamine (MPD) as reducing agents. The formation of the silver nanoparticles was monitored using ultraviolet–visible (UV–Vis) spectroscopy. Both thin film composite (TFC) membrane and thin film nanocomposite (TFN) membrane were hand–cast on performed polysulfone microfiltration (MF) membrane through interfacial polymerization. The surfaces of the membranes were characterized by scanning electronic microscopy (SEM).Theresults indicated that the thin film composite membrane without silver nanoparticles havesmoother surface andare denser than the TFN membrane consisting silver nanoparticles. Chemical analysis was performed with the use of energy dispersive X–ray (EDS). The EDS spectrum showsa sharp peak corresponding to silver<\div>

۴Fabrication and characterizationof polyurethane\3A°zeolite mixed matrix Membrane for gas separation
نویسنده(ها): ، ،
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
Polyurethane was synthesized by using two steps polymerization from toluene diisocyanate(TDI), polypropylene glycol(PPG) and 1,4–butanediamine (BDA). In order to improve gas separation performance of polymeric membranes, micro powder of zeolite was incorporated to them. Mixed matrix membranes (MMMs), consisting of polyurethane\zeolite 3A0 was successfully fabricated by thermal phase inversion method. The prepared MMMs were exposed to O2, CO2, N2, and CH4 gases to determine the permeability and selectivity of PU\3A0 zeolite membranes. The gas permeation experiment was designed by design expert software. The performance of the mixed matrix membranes (PU\3A0 zeolite) was studied as a function of zeolite loading and different operating conditions including pressure and temperature. Zeolite contents of 6, 12, 18, 24 wt% was employed. The obtained results showed that increasing zeolite content caused increasing gas permeabilities of O2, N2, CH4, and CO2.<\div>

۵Pervaporation separation of water\isopropanol mixtures with poly(vinyl alcohol) membranes crosslinked with fumaric acid :Effect of crosslinking time on the mechanical and separation properties
نویسنده(ها): ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۸
Cross–linked Poly (vinyl alcohol) membranes were prepared by using fumaric acid as the crosslinking agent and the effects of cross–linking time on the mechanical properties and membraneperformance in terms of flux and selectivity were investigated. The crosslinking time varied between 10min to 60min .The characteristics of the membranes were determined by Fourier transform infrared (FT–IR) and tensile tests. FT–IR results proved that by increasing the crosslinkingtime more ester groups were formed in the cross–linked membranes. Also, An initial increase was seen for yield stress of the membrane cross–linked for 10 minutes, but further increase in the cross–linking time caused a reduction in this parameter. The effect of feedtemperature and concentration on pervaporation dehydration of water\isopropanol(IPA) were studied for all of the developed membranes.Poly(vinyl alcohol) membranes were crosslinked for60minutes showed the highest selectivity of 1492. The temperature dependency of flux was investigated by using Arrhenius relationship and activation energy calculated for total permeation flux(Ep), water flux(Epw) and isopropanol(EpIPA). The lower value of Epw in comparison with EpIPA indicates that the developed membranes have excellent dehydration performance.<\div>

۶Experimental Study of Batch Electrodialysis Process in Separation of Sodium Sulfate from Magnesium Stearate Aqueous Slurry
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۸
Magnesium stearate (MgSt) is a widely used powder lubricant in the pharmaceutical industry whose mixing dynamics remain poorly understood. MgSt is the preferred lubricant in the pharmaceutical industry because of its low cost and high lubrication potential, melting point, and chemical stability. It is insoluble in water due to its highly apolar molecular structure .In a designed research, batch electrodialysis process were used to remove existing sodium sulphate, an impurity in MgSt aqueous slurry solution.A three compartments experimental electrodialysis system were designed and implemented to increase purification of MgSt. Electrodialysis is a technique based in the transport of ions through selective membranes under the influence of anelectrical field. This technique has proved its feasibility and high performance in the separation and desalination of brackish water. In this paper influence of effective parameters such as applied voltage, feed concentration, time and stirrer speed on removal of sodium sulphate are represented. Based on gained results the amount of salt in MgSt aqueous solution was noticeably reduced.<\div>

۷Effect of Nanofluid on Mass Transfer Coefficient of CO2 in a Wetted Wall Column
نویسنده(ها): ، ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۷
In this study a new method for enhancing the mass transfer coefficient in the gas absorption process is reported. Absorption of CO2 was measured into an aqueous solution of Al2O3\Water nanofluid in a wetted wall column. γ –Alomina nanofluid with the concentrations of 0, 0.01,0.05, 0.1, 0.5, and 1 v\v % has been used as solvent. Effects of some parameters such as gas and liquid mass flow rate and nanoparticle concentration on mass transfer coefiicient has beeninvistigated expaerimentally. It is found that the mass transfer enhancement from the Al2O3\Waternanofluid becomes higher than that from the base fluid (water). The value of volumetric liquidside mass transfer coefficient (kL), increased with increasing Alumina nanoparticles concentration. The maximum enhancement of mass transfer belongs to the 1% volume fraction ofaluminium oxide which increase the mass transfer coefficient up to 55%.<\div>

۸Effect of multi wall carbon nanotube on vacuum membrane distillation performance of microporous polyvinylidene flouride membranes
نویسنده(ها): ، ،
اطلاعات انتشار: چهارمین همایش علمی مهندسی فرآیند، سال
تعداد صفحات: ۱۰
Membrane technology has gradually become a popular separation technology over the past few decades. There are many significant advantages to use membranes for industrial processes. MWCNT possible locations for small molecules are absorbed. Since the transmission properties of CNTs is always the key issue is to improve the properties of polymeric membranes to separate the CNTs are able to transfer the molecules studied. MWCNT\PVDF membranes were fabricated using solution casting method. The synthesized membranes were structurally characterized using Fourier transform infrared spectroscopy, scanning electron microscope and thickness of membrane. The membrane performance was tested by vacuum membrane distillation setup. SEM images showed appropriate distribution of multi wall carbon nanotubes within polyvinylidene fluoride matrix. FTIR analysis showed a physically linking between the nanoparticles and the polymeric matrix of the membrane. Thickness of membranes wasabout 40,50 µm. The MD performance of neat PVDF and MWCNT\PVDF flat sheet membranes with the approximate contact area of 32 cm2 was examined in a vacuum membrane distillation setup. The pure water flux for PVDF\MWCNT and neat PVDF membranes was 8.44 ,11.25(kg\m2h), Respectively. Pure water flux test showed that increasing the nanoparticle, pore wetting is reduced. so, the hydrophobicity is increased.<\div>
نمایش نتایج ۱ تا ۸ از میان ۸ نتیجه