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Fibrous material is being developed that has a conductive polymer coating to achieve effective millimeter wave (MMW) screening performance in an aerosol cloud, and then degrade to a conductively inactive form after settling out. Designing degradability into the material addresses the problem of environmental persistence that is present in the current MMW screening fiber. Synthesis and processing of the candidate fibers is guided by an obscuration modeling program which identifies predicted electromagnetic characteristics as calculated from the interplay of material properties and fiber dimensions. Experimental results are presented comparing the conductivity and the coating quality for doped polypyrrole that is polymerized onto various fiber substrates by a solution process using various solvents and a nonsolution vapor phase process. A new, self-automated, vapor process was developed that produced coated fibers that exhibit higher conductivity values when compared to coated fibers produced by other methods. Single fiber conductivity measurements for the coated fibers are used to assess the quality and the potential screening performance of the conductive polymer coating. Studies have also been conducted on the degradability of the doped polypyrrole coating under outdoor sunlight and humidity conditions. In addition, attenuation studies using a 3 5 GHz transmissometer have been conducted to measure the dissemination and obscuration of the coated fibers.

The Martin Marietta Ocala Plant processes copper plated wiring boards (PWB) for missile guided systems. The boards require several processing steps that use chemical baths. These chemical baths eventually become spent due to a build up of undesirable chemical species that contaminate the boards, and cause the boards to fail quality assurance tests. The spent baths are replaced, treated on site, and then disposed of off site. Martin Marietta contracted the University of Central Florida, Chemistry and Environmental Engineering Departments to develop treatment methodologies for the spent baths produced during PWB's processing. During phase I of the project, treatment methodologies were developed for all waste streams except for the ammonium bifluoride (ABF), NH4HF2, waste. Developing a treatment for the ABF waste was vital, as it represented 24% of the hazardous waste generated at the Ocala facility. A control guide for determining when the ABF bath was spent, and a treatment system for the spent ABF were developed during phase II of the project. The ABF bath removes the glass burrs that are formed by the drilling of holes through stacks of PWB's. The ABF bath leaves a smooth, clean surface that can be electroless plated with copper. To avoid contamination of PWB's the ABF is replaced every two weeks regardless of the production rate. The problem of dumping on a calendar basis, is that production rates vary greatly and consequently "good" ABF baths are being dumped prior to expenditure. In addition, spent ABF can not be incorporated with the treatment processes for other waste streams containing fluoride, due to the high concentration of ammonium ion. The neutralization of the fluoride wastes would cause ammonia gas to evolve from the spent ABF, this is an undesirable byproduct. Attempts to remove the ammonium ion by oxidation with ozone, proved unsuccessful. Dissolving of the glass burrs produces fluorosilicic acid (FSA), H2SiF6 As FSA increases in concentration, the effectiveness of the ABF decreases due to the loss of the reactive species, hydrofluoric acid. In addition, FSA participates in forming fluoride sludges that contaminate the PWB's. Therefore, the concentration of FSA was tracked during processing to determine if it can be used as a control guide to indicate when the ABF was spent. The ABF manufacturer, recently suggested that copper can be used as a contol guide to determine when the ABF is spent. They recommended dumping the ABF when it reached 700 ppm in copper. They found that copper forms a cupric chloride etch with hydrochloric acid, in the ABF, that causes "smutting" of the PWB's. Therefore, causing the PWB's to fail quality assurance tests. To remove these contaminates from the spent ABF, a treatment system using ion exchange resins was tested. The ion exchange resins were selected for their ability to remove copper and FSA at the pH of the spent ABF. To avoid contamination of the ion exchange resins, the ABF was filtered prior to being introduced to the resins. The effluent from the ion exchange columns was found to have a reduction in the copper and FSA concentrations. The reconditioned ABF can be recycled back into production. The resin columns were easily regenerated and can be reused to treat spent ABF. The waste eluted from the columns can be incorporated into present treatment processes at the Ocala facility. Review of the data, indicated that the monitoring of the copper concentration, can be used as a control for determining when the ABF bath is spent. The spent ABF can be recycled back into production, by using ion exchange resin that lowers the copper and FSA levels in the ABF bath.

In this project, new catalyst systems for the vapor phase synthesis of carbon filaments were tested in order to improve the yield of filament, and also the quality of the filaments. Two types of processes were used: a batch process and a continuous process. Three types of hydrocarbon feedstocks were used: ethylene, hexane, and JP-8. In the batch reactor three catalyst systems were tested: a H2S treated Fe203 catalyst, a Fe20JIS04 catalyst treated with elemental sulfur, and a NiS catalyst. A study of optimal conditions for synthesizing carbon filaments in a continuous vertical reactor was performed using a Fe(C0)5 catalyst. During the course of the work, an important discovery was made; that being that the iron pentacarbonyl catalyst was found to be a very active catalyst for promoting filament growth. Morphological and structural characterizations of the filaments were made using scanning electron microscopic methods. Conductivity and surface area of the carbon filaments were measured by using a four point probe technique and a BET analyzer.

The goal of this research was to develop methods of measuring concentrations of contaminants present in space­craft processing environments. Two projects were directed at measuring amounts of non­volatile residue (NVR) present in precision cleaning solvents, where NVR is material which remains after evaporation of the sol vent. These sol vents are used to clean components of spacecraft hardware. A measure of NVR is necessary to determine if the components have been sufficiently cleaned. A third project was directed at developing infrared laser photoacoustic to determine airborne contaminant concentrations. The contaminants studied, if present inside the spacecraft, can damage payload optical systems when deposited on their surfaces. contaminant detection method is necessary to measure the concentrations when the exposure occurs in order to prevent damage which otherwise may not be known until after the payload has been launched.

Recent advances in metal fiber production have resulted in the capability of large scale production of very small diameter filaments of nickel called nickel microwircs. These nickel microwires were studied as potential new catalysts for use in hydrogenation reactions. The studies were carried out by the hydrogenation of 1-octene al various reaction conditions. This study shows that 2µm diameter nickel microwires exhibit very high activity and a long life time as compared to other commonly used industrial nickel catalysts. This tudy also shows that the activity of the nickel microwires is affected by the diameter of the wire. the method by which the microwirc is manufactured and the method of pretreatment of the microwire prior to use. Data show that a high specific surface area and an apparent high density of active sites and low activation energy are responsible for the high catalytic activity of the nickel m1crow1res. The results of this study show that nickel microwires are easy to use in heterogeneous stirred tank reactors and possess the potential for being very useful industrial hydrogenation catalysts.

The use of alumina supported transition metal oxides in catalysis of the total "deep" oxidation of dichlorodifluoro­methane was studied. The study reveled an activation energy trend in the transition metals' dichlorodifluoromethane oxidation capabilities that patterns periodic table position of d-orbital electron occupancy. Rate constants and activation energies were determined for catalysts synthesized for each transition metal in the first row of the series. The catalyst with the lowest determined activation energy and highest rate constants was determined to be a 3% by wt. Ni based catalyst of NiO/Al203• Variation in trends with normal n-type, p-type semiconductors behavior in oxidation patterns were examined and Zn was determined to act differently than previously patterned based on oxidation mechanisms.

There are many different types of targeted therapy for cancer treatment. The method of light mediated targeted therapy that we have developed uses photocaged molecules and photoswitchable peptides. In photocaging, a biologically active molecule is made inactive by the attachment of a photocleavable blocking group. On exposure to UV radiation the photocleavable entity is removed and the biologically active molecule is released. Using this concept we have designed a prodrug that consists of a cell impermeable hydrophilic molecule attached to a photocaged doxorubicin. Upon irradiation with UV light the photosensitive group is removed and cytotoxic doxorubicin is released at the tumor site. This concept has been further modified by attaching receptor binding molecules to the photocaged entity to increase its specificity. A peptide which consists of an azobenzene photoswitch has been used which, in the dark state is randomly coiled and cell impermeable but upon illumination becomes helical and cell permeable and can be used to deliver drugs into the cells. Upon illumination with UV light of suitable wavelength the azobenzene linker will change from a trans to a cis form and this will convert the randomly coiled cell impermeable peptide into an α helical permeable form. Thus a series of peptides have been designed with different arginine mutations which develop an arginine patch in the helical form. This arginine patch would help in cell permeability by interacting with cell surface glycans. The method could potentially be used to deliver drugs into cells in presence of light.

A thorough understanding of the underlying electronic principles guiding the stability and reactivity of clusters has direct implications for the identification of stable clusters for incorporation into clusters-assembled materials with tunable properties. This work explores the electronic principles governing the stability and reactivity of two types of clusters: ligated metal clusters and silicon encapsulated transition metal clusters. In the first case, the reactivity of iodine-protected aluminum clusters, Al13Ix- (x=0-4) and Al14Iy- (y-0-5), with the protic species methanol was studied. The symmetrical ground states of Al13Ix- showed no reactivity with methanol but reactivity was achieved in a higher energy isomer of Al13I2- with iodines on adjacent aluminum atoms – complementary Lewis acid-base active sites were induced on the opposite side of the cluster capable of breaking the O-H bond in methanol. Al14Iy- (y=2-5) react with methanol, but only at the ligated adatom site. Reaction of methanol with Al14- and Al14I- showed that ligation of the adatom was necessary for the reaction to occur there – revealing the concept of a ligand-activated adatom. In the second case, the study focused heavily on CrSi12, a silicon encapsulated transition metal cluster whose stability and the reason for that stability has been debated heavily in the literature. Calculations of the energetic properties of CrSin (n=6-16) revealed both CrSi12 and CrSi14 to have enhanced stability relative to other clusters; however CrSi12 lacks all the traditional markers of a magic cluster. Molecular orbital analysis of each of these clusters showed the CNFEG model to be inadequate in describing their stability. Because the 3dz2 orbital of Cr is unfilled in CrSi12, this cluster has only 16 effective valence electrons, meaning that the 18-electron rule is not applicable. The moderate stability of CrSi12 can be accounted for by the crystal-field splitting of the 3d orbitals, which pushes the 3dz2 orbital up in energy. CrSi14, on the other hand, has 18 effective valence electrons on Cr, minimal 3d-orbital splitting, and does follow the 18-electron rule. A repetition of these calculations with WSin (n=6-16) showed similar results, except WSi12 shows all the markers of a magic cluster, due to the greater crystal-field splitting of 5d orbitals.

Denna forskningsrapport fokuserar på gymnasieskolans laborationer i kemi och hur dessa förändrats under de senaste 10-20 åren. Motivet till att studera detta är ambitionen att få ökad didaktisk förståelse för laborationen som viktigt inslag i kemiundervisningen. I ett större perspektiv kan detta vara av intresse för att analysera om förändringar av gymnasieskolans kemilaborationer kan utgöra en delförklaring till att svenska universitet upplever ett minskat söktryck för kemi på högskolenivå och om delförklaring kan finnas för att Sverige som nation inte når samma resultat i naturvetenskap som vissa andra länder i internationella kunskapsmätningar. Sex erfarna lärare från sex olika skolor har intervjuats om sina upplevelser av kemilaborationen och vad som påverkat dess utveckling. Ramfaktorteorin har varit grundläggande för detta arbete och som analysmetod har fenomenografin valts. Resultaten visar på en stor variation i vad lärare anser påverkat kemilaborationens förändring. Ökat medvetande och högre krav från lagar och förordningar inom säkerhetsområdet samt att lärare upplever sig ha mindre tillgänglig tid för laborationerna framstår som de tydligaste orsakerna till gjorda förändringar. Även kompensation för försämrade praktiska färdigheter hos elever som lämnar grundskolan framkommer som en bakomliggande faktor. Den nya läroplanen Gy 2011, kostnadsöverväganden och kemi­lokalernas beskaffenhet framkom som mindre avgörande för kemilaborationens utveckling.