BACKGROUND: TIO2-CMK-8 CATALYSIS THE RING-OPENING OF EPOXIDES WITH ACYL HALIDES AFFORDING THE CORRESPOND 2-HALOALKYL ESTERS [1]. TRANSFORMATION OF EPOXIDES TO 1, 2-DISUBSTITUTED ALKANES IS ONE OF THE IMPORTANT PROCESSES IN ORGANIC SYNTHESES, AND EXTENSIVE STUDIES ON THE REGIO- AND STEREOCHEMISTRY OF THE RING-OPENING REACTION OF EPOXIDES WITH SEVERAL NUCLEOPHILES CATALYZED BY TRANSITION METALS HAVE BEEN REPORTED. …

BACKGROUND: RECENTLY MANY STUDIES HAVE BEEN DONE ON THE SYNTHESIS OF HETEROGENEOUS ACID CATALYSTS [1]. MANY HETEROGENEOUS CATALYSTS ARE LESS ACTIVE THAN THE HOMOGENEOUS CATALYSTS BECAUSE THE REACTION RATES ARE LIMITED BY THE TRANSPORT OF THE REACTANT TO THE ACTIVE SITES ON THE PARTICLE SURFACES. THE UTILITY OF HETEROGENEOUS CATALYSTS CAN BE IMPROVED BY USING HIGH SURFACE AREA MATERIALS SINCE THE TRANSPORT OF THE REACTANTS TO THE ACTIVE SITE ON PARTICLE SURFACE CAN BE ENHANCED BY THIS METHOD. AMONG THE ORDERED MESOPOROUS MATERIALS, CARBON MESOPOROUS MATERIALS (CMK-1, CMK-3, AND CMK-8) ARE THE MOST IMPORTANT MESOPOROUS MATERIALS WHICH HAVE SPECIAL CATALYTIC PROPERTIES BECAUSE OF THEIR INTERCONNECTED LARGE PORE NETWORKS [2]. IN THE PRESENT WORK POLYVINYLSULFUNIC ACID/CMK-3 WAS PREPARED AS A NOVEL ACID CATALYST. THE CATALYTIC ACTIVITY OF THIS CATALYST WAS INVESTIGATED IN REDUCTIVE AMINATION OF ALDEHYDES.METHODS: CMK-3 WAS PREPARED USING SBA-15, SUCROSE, SULFURIC ACID AND WATER. THEN, POLY VINYL SULFUNIC ACID/CMK-3 WAS PREPARED THROUGH IN SITU POLYMERIZATION OF VINYL SULFUNIC ACID IN THE PORES OF CMK-3. THE REDUCTIVE AMINATION CARRIED OUT WITH EQUIMOLAR AMOUNT OF AMINE AND ALDEHYDE USING POLYVINYLSULFUNIC ACID/CMK-3 AS CATALYST, SODIUM BOROHYDRIDE IN THF AT ROOM TEMPERATURE [3].RESULTS: THE POLYVINYLSULFUNICACID/CMK-3 WAS PREPARED AND CHARACTERIZED BY FT-IR, XRD, SEM, TEM AND BET TECHNIQUES. THE RESULTS SHOWED THAT THE NANOCOMPOSITE WAS SYNTHESIZED AS WELL AS EXPECTED. THE REDUCTIVE AMINATION OF ALDEHYDES WAS CARRIED OUT OVER POLY VINYL SULFUNIC ACID/CMK-3. THE REACTION WAS COMPLETED IN A SHORT TIME (15 MIN) IN WATER AS A GREEN SOLVENT.CONCLUSION: POLY VINYL SULFUNIC ACID/CMK-3 WAS PREPARED A NOVEL HETEROGENEOUS CATALYST WHITH HIGH SURFACE AREA WHICH SHOWED GOOD CATALYTIC ACTIVITY IN REDUCTIVE AMINATION OF ALDEHYDES.

MANGANESE DIOXIDE (MNO2) HAS ATTRACTED CONSIDERABLE ATTENTION BECAUSE IT IS ABUNDANT, INEXPENSIVE, ENVIRONMENTALLY FRIENDLY AND HAS HIGH ENERGY DENSITY. MNO2 CAN BE APPLIED IN DIVERSE APPLICATIONS, SUCH AS CATHODE MATERIALS FOR METAL–AIR BATTERIES, FUEL CELL AND AS CATALYSTS FOR THE AEROBIC OXIDATION OF ALCOHOLS AND THE OXIDATION OF CARBON MONOXIDE. HOWEVER, THE POOR ELECTRICAL CONDUCTIVITY OF MNO2 (10-5 TO 10-6 S/CM) LIMITS MNO2 FROM PRACTICAL USE IN ELECTROCHEMICAL DEVICES. TO OVERCOME THIS LIMITATION, TWO STRATEGIES ARE USUALLY ADOPTED. ONE OF THESE STRATEGIES IS TO DEPOSIT A THIN LAYER OF MNO2 OR MNO2 NANOPARTICLES ONTO THE SURFACE OF ELECTRICALLY CONDUCTIVE SUBSTRATES, INCLUDING ACTIVE CARBON BLACK, CARBON NANOTUBES (CNTS), AND GRAPHEME AND CMK-1[1]. HIGHLY ORDERED MESOPOROUS CARBON HAVE DESIGNATED AS CMK-1 HAVE MANY UNIQUE PROPERTIES SUCH AS HIGH SURFACE AREA, HIGH CHEMICAL STABILITY AND HIGH CONDUCTIVITY [2]. IN THIS WORK CMK-1 WERE SYNTHESIZED USING ORDERED MESOPOROUS SILICAS MCM-48 AS SILICA TEMPLATE, SUCROSE AS A CARBON SOURCE AND SULFURIC ACID AS THE CARBONIZATION CATALYST [3]. AND FOR SYNTHESIZED OF MCM-48, TETRAETHOXYORTHOSILANE (TEOS) WAS USED AS THE SILICA SOURCE AND CETYLTRIMETHYLAMMONIUM BROMIDE (CTAB) AS THE TEMPLATE CONSTITUENTS [4]. TO EVALUATE THE SURFACE AREAS OF CMK-1 AND DETERMINE THE PORE STRUCTURES OF THE SAMPLES, N2 ADSORPTION/DESORPTION ISOTHERMS WERE INVESTIGATED. THE X-RAY DIFFRACTION (XRD) PATTERNS OF THE MNO2/CMK-1 DETERMINED CRYSTAL STRUCTURE. SED- EDS OF SAMPLE SHOWED MORPHOLOGY AND PORE SIZE OF SAMPLE. ELECTROCHEMICAL BEHAVIOR OF THIS SYNTHESIZED CATHODE SUCH AS DISCHARGE TEST AND CYCLIC VOLTAMMETRY (CV) HAS SHOWED GOOD RESULTS.

RECHARGEABLE LI-S BATTERIES HAVE RECEIVED EVER-INCREASING ATTENTION RECENTLY DUE TO THEIR HIGH THEORETICAL SPECIFIC ENERGY DENSITY, WHICH IS 3 TO 5 TIMES HIGHER THAN THAT OF LI-ION BATTERIES BASED ON INTERCALATION REACTIONS. LI-S BATTERIES MAY REPRESENT A NEXT-GENERATION ENERGY STORAGE SYSTEM. HOWEVER, IT HAS BEEN REPORTED THAT LI-S BATTERIES WITH ORGANIC LIQUID ELECTROLYTE HAVE SOME PROBLEMS RELATED TO LOW ACTIVE MATERIALS UTILIZATION EFFICIENCY AND POOR CYCLE LIFE, BECAUSE OF THE INSULATING NATURE OF SULFUR AND THE SOLUBILITY OF POLYSULFIDES GENERATED DURING THE ELECTROCHEMICAL REACTION PROCESS [1]. IN THIS RESEARCH, TO SOLVE THESE PROBLEMS, MESOPOROUS CARBON (CMK-1) WAS SYNTHESIZED AND IT WAS USED TO ABSORB THE POLYSULFIDE WHICH FORMS DURING THE FIRST DISCHARGE STEP OF A LI/S BATTERY. CMK-1 IN THE ELECTRODE NOT ONLY ACTS AS AN ADSORBENT FOR THE POLYSULFIDE, BUT ALSO ACTS AS AN ELECTRICALLY CONDUCTING ADDITIVE [2]. CMK1- S NANOCOMPOSITE WITH WEIGHT RATIOS OF 70:30, 60:40 AND 50:50 WERE PREPARED BY HEATING THE MIXTURE OF SULFUR AND CMK-1 AT 155O FOR 4H UNDER N2 PROTECTION [3]. DIFFERENT TECHNIQUE SUCH AS DSC/TGA, ICP, XRD, TEM AND BET WERE EMPLOYED TO CHARACTERIZE THE CHEMICAL COMPOSITION, SURFACE AREA, PORE AND VOLUME SIZE AND MORPHOLOGY OF ELECTRODE MATERIALS. FINALLY THE ELECTROCHEMICAL PERFORMANCE OF CMK1-S NANOCOMPOSITE WAS INVESTIGATED BY CHARGE-DISCHARGE AND CYCLIC VOLTAMMETRY METHODS. THE RESULTING OF THESE TESTS REPRESENTING A PROMISING CATHODE MATERIAL FOR RECHARGEABLE LITHIUM BATTERIES WITH HIGH ENERGY DENSITY.