Gas Separation Properties of the Dense Polymer-Zeolite Powder Composite Membranes

The natural balance in the Earth's atmosphere is significantly influenced by the human emission of the combustion products, mainly carbon dioxide. Therefore, strong efforts are directed in the direction of the reduction of that emission. The solution might be searched in the direction of the construction of the membrane that would be highly transparent to the carbon dioxide, but not transparent to the other gases commonly present in the waste gases (oxygen, nitrogen, hydrogen, methane). One of the feasible designs for this purpose is dense, non-porous membranes, with zeolite particles dispersed in the polymer matrix. Zeolite particles should increase the solubility of the carbon dioxide, and thus enhance its permeability. In this paper, the possibility of application of polyether-b-amide (with 60% of PEG) as a polymer matrix was tested. For the inorganic component, four different zeolite types with three different pore geometries were tested. The influence of the additive which was added in order to provide good contact between the highly polar and charged zeolite inorganic particle, and hydrophobic polymer chains was also tested

Treatment of Waste Copper Electrolytes Using Insoluble and Soluble Anodes

The use of copper anodes with non standard content of impurities for the treatment of waste, sulphur acid solutions that came as a result of the industrial process of electrolytic copper refining was investigated. Those solutions contain the high content of copper, nickel and arsine, and because of that, the copper anodes with high content of Ni, Pb, Sn and Sb were prepared. Examination the effect of high impurities content as well as the influence of the solution temperature on the anodes behaviour during the electrolytic process under the conditions that are the same as the industrial was the aim of this work. Obtained results clearly indicate that tested anodes could be used for the refined during the electrorefining process. Dissolution of copper anodes was not stoppage after the first appearance of the passivation region for A1 and A2 anodes while appearance of passivation for A3 anode, for test duration of 72 h, was not registered. The start time of the first passivation appearance is shorter in the case of the anode with high content of all impurities, anode A1. The first passivation occurrence was detected on higher temperature after about 29 h from the test starts. The change of chemical composition of electrolyte was monitored during electrolysis. Concentration of nickel in the working electrolyte at the end of process is increased and it corresponds to the Ni content in anodes. The copper and arsenic concentrations are decreased during the process. Arsenic passes into the anode slime, while the copper is deposited on the cathode and also passed in the slime. After the process is finished, obtained solution could be used for the nickel recover using the electrochemically or chemically methods

Influence of composition of the magnetic composite coating on the performance of the optical fiber magnetic field sensing element

The optical fiber magnetic sensing element (OFMSE) based on the optical fiber coated with composite coating polymermagnetic powder has been already introduced in magnetic field sensing. In this research, the rapid quenched Nd-Fe-B powder with Nd rich content was used as magneto-active component in composite coating. Magnetic powder was dispersed in poly-(ethylene-co-vinyl- acetate) - EVA solution in toluene. The influence of magnetic powder content (20, 30, 40 and 50 mass %) in composite coating of multimode optical fiber on the thickness, hardness and uniformity was observed and discussed. Sensitivity and reversibility of the constructed OFMSE in the external magnetic field are illustrated

Polimerni magnetni kompoziti na bazi Nd-Fe-B

Various types and contents of magnetic powder and polymer matrix induce different mechanical, magnetic, electrical and optical properties of final composite material. The strong influence of relatively small amounts of filler particles on the dynamic mechanical properties of polymers has significantly contributed to increased use of polymer materials in many commercial applications. The higher content of magnetic filler has direct influence on magnetic properties of composites, but also may change the rheology of polymer melt during process and, subsequently, impact the mechanical strength of bonded magnets. For better insight into viscoelastic behaviour of composites, beside experiments, a theory that explicitly takes the shape factor, particle distribution, particle-particle interactions as well as particle-polymer matrix interactions into account is required. The mathematical prediction of storage modulus behaviour is examined. The several proposed analytical models are tested versus experimental results. Some of applied models agree very well with experimental data, whilst others deviate significantly.Različite vrste primenjenih magnetnih prahova i polimerne matrice, kao i njihovi udeli, utiču na mehanička, magnetna, električna i optička svojstva finalnog kompozitnog materijala. Veliki uticaj relativno malih udela čestica punioca na dinamičko mehanička svojstva polimera značajno doprinosi većoj komercijalnoj upotrebi kompozitnih materijala. Veliki udeli magnetnog praha u mnogome utiču na magnetna svojstva kompozita, ali takođe mogu dovesti do reoloških promena u polimeru tokom procesa topljenja, što ima direktan uticaj na mehanička svojstva polimerom vezanih (bonded) magneta. Radi boljeg uvida u visokoelastična svojstva kompozita, osim eksperimenata, neophodno je uzeti u obzir i teorijska razmatranja koja eksplicitno objašnjavaju uticaj faktora oblika, raspodelu čestica, interakcije između čestica, kao i interakcije između čestica i polimera. U tom smislu vršeno je i matematičko predviđanje ponašanja modula uskladištene energije (E') kompozita. Nekoliko predloženih analitičkih modela su testirani i upoređeni sa eksperimentalnim rezultatima. Neki od primenjenih modela se veoma dobro slažu sa dobijenim eksperimentalnim rezultatima, dok neki značajno odstupaju

Evolution of microstructure of melt-spun Nd-Fe-B alloy with low Nd content during the heat treatment

In order to examine and study evolution of microstructure during the phase transformations for applied heat treatment regime for achieving the optimal values of magnetic properties of the investigated melt-spun Nd-Fe-B alloy with low Nd content were using different techniques and methods including SEM with EDS, DTA, XRD, MS analysis and magnetic measurements also

Using the Low-Cost Waste Materials for Heavy Metals Removal from the Mine Wastewater

The possibility of application of low-cost and easily available materials such as cardboard or sawdust for the heavy metals removal from the acid mine water was investigated. The sawdust was obtained from oak and fir-wood. Those materials were tested on the real acid mine wastewater that contained copper, iron, zinc, nickel, and manganese in the concentrations above the maximal allowed level. The adsorption degrees of those elements were investigated. The results were shown that the iron was mechanically removed. The results of chemical analysis of effluent obtained by the use of sawdust from fir-wood indicate that the values for iron and nickel ions were lower than allowed values by the legislative direction. The highest value for copper adsorption degree of 98.31% was achieved at pH value of 7.94. Content of manganese in the effluent and at the end of process, was near the initial value. Using the sawdust obtained from oak as the adsorption material, zinc and manganese concentration in the effluent was near the start values and copper and iron content was decreased but the values were higher than allowed. Using the cardboard, the copper adsorption degree was up to 95 mass%, iron content was under the limit value for the applied chemical detection method. The content of the manganese was not changed and the content of the zinc was decreased but the concentration was over the maximum allowed value. [doi:10.2320/matertrans.M2011191

Using the Low-Cost Waste Materials for Heavy Metals Removal from the Mine Wastewater

The possibility of application of low-cost and easily available materials such as cardboard or sawdust for the heavy metals removal from the acid mine water was investigated. The sawdust was obtained from oak and fir-wood. Those materials were tested on the real acid mine wastewater that contained copper, iron, zinc, nickel, and manganese in the concentrations above the maximal allowed level. The adsorption degrees of those elements were investigated. The results were shown that the iron was mechanically removed. The results of chemical analysis of effluent obtained by the use of sawdust from fir-wood indicate that the values for iron and nickel ions were lower than allowed values by the legislative direction. The highest value for copper adsorption degree of 98.31% was achieved at pH value of 7.94. Content of manganese in the effluent and at the end of process, was near the initial value. Using the sawdust obtained from oak as the adsorption material, zinc and manganese concentration in the effluent was near the start values and copper and iron content was decreased but the values were higher than allowed. Using the cardboard, the copper adsorption degree was up to 95 mass%, iron content was under the limit value for the applied chemical detection method. The content of the manganese was not changed and the content of the zinc was decreased but the concentration was over the maximum allowed value

Dynamic Mechanical Behaviour of Polymer Bonded Nd-Fe-B Composite Materials

Magnetic composite materials with varied content of Nd-Fe-B particles in epoxy matrix are examined from a dynamic mechanical perspective. Structural, viscoelastic and magnetic properties of composites have been observed using Scanning Electron Microscope (SEM), Dynamic Mechanical Analysis (DMA) and Super Quantum Interference Device (SQUID) magnetometer, respectively. Experimental results show that magnetic properties and corresponding dynamic mechanical behaviour depend on packing density. Also, results observed by predictive mathematical models suggest that maximal packing factor has a direct impact on elastic behaviour of composites. [doi:10.2320/matertrans.M2011218

The influence of concentration of Nd-Fe-B powder in composite coating of optical fiber to the sensibility to external magnetic field

Multi-mode optical fiber with magnetic composite coating was investigated as an optical fiber sensor element (OFMSE) for magnetic field sensing The composite coating was formed with dispersions of permanent magnet powder of Nd-Fe-B in poly (ethylene-co-vinyl acetate)-EVA solutions in toluene. The influence of the applied external magnetic field on the change of intensity of the light signal propagate trough developed optical fibers sensor element was investigated. In this paper the influence of the content of magnetic powder in the composite coating on the optical propagation characteristics of optical fiber were particularly investigated

Optical fibers with composite magnetic coating for magnetic field sensing

The investigated system for optical fiber sensor was multi-mode optical fiber with magnetic composite coating. Polymer component of composite coating was poly (ethylene-co-vinyl acetate)-EVA, and the magnetic component was powder of SmCo5 permanent magnet in form of single domain particles. The influence of the applied external magnetic field on the change of intensity of the light signal propagated through optical fiber was investigated