Providing safe drinking water and wastewater remediation are constant worldwide challenges. Adsorption is an attractive alternative to conventional techniques such as coagulation, precipitation (chemically or electrochemically), hybrid membranes, and ion-exchange for the purification of water. Biochar-based composite sorbents are increasingly popular because a range of surface chemical and physical treatments can impart performance and environmental benefits to the material. This is ideal for rural areas where more costly conventional methods may not be readily available or affordable. This dissertation focused on three different projects involving high surface area (~700 m2/g) Douglas fir biochar based multifunctional engineered adsorbents. Chapter II focuses on arsenic (III) adsorptive removal onto magnetic iron oxide dispersed onto biochar. This chapter highlights the adsorptive and redox properties of biochar composites for pollutant toxicity reduction. Chapter III focuses on pollutant toxicity neutralization after adsorption, simultaneous adsorption, and multi-phase adsorption. A MIL-53-MOF magnetite/magnetic biochar composite model system was used to demonstrate simultaneous chromium (VI) adsorption and organic pollutant rhodamine (RhB) degradation. Chapter IV is focused on tailoring the biochar to change its physical properties (enhance hydrophobicity) to achieve a specific pollutant treatment requirement (buoyancy). Oil spill remediation was used as a model example for this purpose and lauric acid-decorated magnetite biochar composite was introduced. The composites and their pollutant-loaded analogues were extensively characterized using BET, SEM, TEM, EDS, XRD, VSM, PZC, Elemental analysis, TGA, DSC, FT-IR and XPS.

Multifunctional composites have gained significant interest as they enable the integration of sensing and communication capabilities into structural, lightweight composites. Researchers have explored additive manufacturing processes for creating these structures through selective patterning of electrically conductive materials onto composites. Thus far, multifunctional composite performance has been limited by the conductivity of functional materials used, and the methods of integration have resulted in compromises to both structural and functional performance. Integration methods have also imposed limitations on part geometry due to an inability to adequately deposit conductive material over concave surfaces. Proposed methods of integrating functional devices within composites have been shown to negatively affect their mechanical performance. This work presents a novel method for integrating printed electronics onto the interior surfaces of closed, complex continuous fiber composite structures via the transfer of selectively printed conductive inks from additively manufactured sacrificial tooling to the composite surface. The process is demonstrated by creating multifunctional composites via embossing printed electronics onto structural composites without negatively affecting the mechanical performance of the structure. Additionally, this process expands the ability to pattern devices onto complex surfaces and demonstrates that the transferred functionality is well integrated (adhered) with the composite surface. The process is further validated through the successful completion of two separate case studies. The first is the integration of a functioning strain gauge onto an S-glass/epoxy composite, while a second process demonstration shows a composite surface featuring a band stop filter at the X-band, otherwise known as a frequency selective surface (FSS), to show the process' suitability for high performance, aerospace grade multifunctional composites. / Master of Science / Significant interest has been given in the past few decades to strong, lightweight materials for structural purposes. Among these materials, specific interest has been paid to fiber-reinforced composites, which are made of strong fibers and advanced resins. Recently, researchers have tried to use electrically conductive inks and 3D printing techniques to put antennas and other devices onto composites. These composites could possess additional functions beyond their structural purpose and are therefore called multifunctional composites. So far, the performance of multifunctional composites has been limited by the methods used to add additional functions. These methods often result in a weaker composite material and poor performance of the added devices. In this work, a new method for integrating devices onto complex-shaped composite structures is demonstrated. This is done by printing a mold for a composite, then putting a conductive ink onto the mold and transferring the ink to the composite surface. This process is demonstrated without weakening the composite. Additionally, this process allows researchers to put devices onto complex surfaces and demonstrates that the devices are secured to the composite surface. The process is used to make two separate devices and combine them with a composites surface. The first demonstration is the integration of a functioning strain gauge (used to measure a change in material dimension) onto a structural composite, while a second process demonstration shows a composite surface featuring an electromagnetic filter, otherwise known as a frequency selective surface (FSS), to show the process' suitability for high performance, aerospace grade multifunctional composites.

Energy harvesting technology has the ability to create autonomous, self-powered electronic systems that do not rely on battery power for their operation. The term energy harvesting describes the process of converting ambient energy surrounding a system into useful electrical energy through the use of a specific material or transducer. A widely studied form of energy harvesting involves the conversion of mechanical vibration energy into electrical energy using piezoelectric materials, which exhibit electromechanical coupling between the electrical and mechanical domains. Typical piezoelectric energy harvesting systems are designed as add-on systems to a host structure located in a vibration rich environment. The added mass and volume of conventional vibration energy harvesting designs can hinder to the operation of the host system. The work presented in this dissertation focuses on advancing piezoelectric energy harvesting concepts through the introduction of multifunctionality in order to alleviate some of the challenges associated with conventional piezoelectric harvesting designs. The concept of multifunctional piezoelectric self-charging structures is explored throughout this work. The operational principle behind the concept is first described in which piezoelectric layers are directly bonded to thin-film battery layers resulting in a single device capable of simultaneously harvesting and storing electrical energy when excited mechanically. Additionally, it is proposed that self-charging structures be embedded into host structures such that they support structural load during operation. An electromechanical assumed modes model used to predict the coupled electrical and mechanical response of a cantilever self-charging structure subjected to harmonic base excitation is described. Experimental evaluation of a prototype self-charging structure is then performed in order to validate the electromechanical model and to confirm the ability of the device to operate in a self-charging manner. Detailed strength testing is also performed on the prototype device in order to assess its strength properties. Static three-point bend testing as well as dynamic harmonic base excitation testing is performed such that the static bending strength and dynamic strength under vibration excitation is assessed. Three-point bend testing is also performed on a variety of common piezoelectric materials and results of the testing provide a basis for the design of self-charging structures for various applications. Multifunctional vibration energy harvesting in unmanned aerial vehicles (UAVs) is also investigated as a case study in this dissertation. A flight endurance model recently developed in the literature is applied to model the effects of adding piezoelectric energy harvesting to an electric UAV. A remote control foam glider aircraft is chosen as the test platform for this work and the formulation is used to predict the effects of integrating self-charging structures into the wing spar of the aircraft. An electromechanical model based on the assumed modes method is then developed to predict the electrical and mechanical behavior of a UAV wing spar with embedded piezoelectric and thin-film battery layers. Experimental testing is performed on a representative aluminum wing spar with embedded self-charging structures in order to validate the electromechanical model. Finally, fabrication of a realistic fiberglass wing spar with integrated piezoelectric and thin-film battery layers is described. Experimental testing is performed in the laboratory to evaluate the energy harvesting ability of the spar and to confirm its self-charging operation. Flight testing is also performed where the fiberglass spar is used in the remote control aircraft test platform and the energy harvesting performance of the device is measured during flight. / Ph. D.

<p>The prevalence of cancer has increasingly become a significant threat to human health and as such, there exists a strong need for developing novel methods for early detection and effective therapy. Nanotheranostics, a combination of diagnostic and therapeutic functions into a single nanoplatform, has great potential to be used for cancer management by allowing detection, real-time tracking, image-guided therapy and therapeutic response monitoring. Gold nanostars (GNS) with tip-enhanced plasmonics have become one of the most promising platforms for cancer nanotheranostics. This work is aimed at addressing the challenges of sensitive cancer detection, metastasis treatment and recurrence prevention by combining state-of-the-art nanotechnology, molecular imaging and immunotherapy. A multifunctional GNS nanoprobe is developed with capabilities ranging from non-invasive, multi-modality cancer detection using positron emission tomography (PET), magnetic resonance imaging (MRI) and X-ray computed tomography (CT), to intraoperative tumor margin delineation with surface enhanced Raman spectroscopy (SERS) and high-resolution nanoprobe tracking with two-photon photoluminescence (TPL), as well as cancer treatment with photoimmunotherapy. The GNS nanoprobe with PET scans is particularly exceptional in detecting brain malignancies as small as 0.5 mm. To the best of our knowledge, the developed GNS nanoprobe for PET imaging provides the most sensitive means of brain tumor detection reported so far. In addition, the GNS nanoprobe exhibits superior performance as photon-to-heat transducer and can be used for specific photothermal therapy (PTT). More importantly, GNS-mediated PTT combined with checkpoint inhibitor immunotherapy has been found to trigger a memorized immunoresponse to treat cancer metastasis and prevent recurrence in mouse model studies. Furthermore, a 6-month in vivo toxicity study including body weight monitoring, blood chemistry test and histopathology examination demonstrate GNS nanoparticles’ biocompatibility. Therefore, the multifunctional GNS nanoprobe exhibits superior cancer detection and treatment capabilities and has great promise for future clinical translation in cancer management.</p> / Dissertation

Selective hydrogenation is an important class of chemical reactions for the production of speciality chemicals, pharmaceuticals and petrochemicals. The challenges in this type of reactions are to control selectivity in hydrogenation of poly-functional molecules, and avoid the possible risk of reaction runaway due to the high exothermisity. In this project the fundamentals of liquid-phase hydrogenation reactions in a structured compact multifunctional reactor were investigated. This technology represents an advance over the existing hydrogenation technologies because it exploits the effects of reduced characteristic paths of mass and heat transfer, attained in compact reactor architecture with mm-scale reaction channels and integrated static mixers and micro-heat exchangers. Catalysts based on mesoporous synthetic carbons were developed especially for preparing micro-packed beds in the compact reactor. The investigation resulted in fundamental information on reactor performance for selected model reactions, heat transfer efficiency of the integrated micro-heat exchangers, development of continuous tandem reaction, and evaluation of developed catalysts for hydrogenation and hydrodehalogenation reactions under the continuous flow conditions being used. The results demonstrate that the structured compact multifunctional reactor might be a promising technology to transfer conventional heterogeneous catalysis to flow regime.

To meet the ever increasing demand of high data rate, millimeter-wave (mm-wave) wireless communication has become an area of intense research due to the capability of offering very broad bandwidth. However, the propagation losses increase as a function of operation frequency. Therefore, there is need for antenna systems with high gain and beam-steering capability at elevated frequencies, which comes at the expense of high cost and increased complexity. This dissertation demonstrates the design, micro-fabrication, and characterization of two different antennas and two different antenna arrays. A broadband patch antenna operating within (57-66) GHz band, which works as a building block to create a multifunctional reconfigurable antenna (MRA) that is capable of beam steering in three directions pertaining to θ ∈{-30°, 0°, 30°}; Φ=90°. These standalone antennas were then put in a linear formation to create a 2x8 planar array and a 4x1 multifunctional reconfigurable antenna array (MRAA) to increase the gain further and to offer wider bandwidth. The proposed novel MRA and MRAA possess variable element factors, which potentially can feature as the main building blocks of mm-wave reconfigurable wireless communication systems with reduced cost and complexity.

Magnetic nanoparticles embedded in polymer matrices have excellent potential for electromagnetic device applications like electromagnetic interference (EMI) suppression. Using chemical precipitation methods and Nanogen , a microwave plasma method, we have synthesized various nanoparticles including iron, polystyrene-coated iron, iron oxide (both hematite and magnetite), nickel ferrite, and manganese zinc ferrite. We have synthesized polymer nanocomposites of polymethylmethacrylate (PMMA), polystyrene (PS), and polypyrrole (PPy) doped with varying concentrations of these nanoparticles. These nanocomposites were processed using melt blending and sonication techniques. The concentration of nanoparticles was varied in a controlled way. Although polymer processing conditions were optimized to achieve good uniform dispersion of the nanoparticles in the polymer matrix, surface characterization with SEM indicates areas of clustering of the nanoparticles. This agglomeration is attributed to the particle interactions mediated by steric forces in the polymer matrix. Static magnetic properties such as susceptibility and M-H loops were studied using a Physical Property Measurement System (PPMS). The variation of the magnetic responses were consistent with the varying volume concentration of the nanoparticles, the polymers themselves contributing diamagnetic responses. Overall, the reasonable dispersion and control over magnetic properties achieved in our experiments is promising for electromagnetic applications of these materials.

Coupling between the electric field, magnetic field, and strain of composite materials is achieved when electro-elastic (piezoelectric) and magneto-elastic (piezomagnetic) particles are joined by an elastic matrix. Although the matrix is neither piezoelectric nor piezomagnetic, the strain field in the matrix couples the E field of the piezoelectric phase to the B field of the piezomagnetic phase. This three-phase electro-magneto-elastic composite should have greater ductility and formability than a two-phase composite in which E and B are coupled by directly bonding two ceramic materials with no compliant matrix. A finite element analysis and homogenization of a representative volume element is performed to determine the effective electric, magnetic, mechanical, and coupled-field properties of an elastic (epoxy) matrix reinforced with piezoelectric and piezomagnetic fibers as functions of the phase volume fractions, the fiber (or particle) shapes, the fiber arrangements in the unit cell, and the fiber material properties with special emphasis on the symmetry properties of the fibers and the poling directions of the piezoelectric and piezomagnetic fibers. The effective magnetoelectric moduli of this three-phase composite are, however, less than the effective magnetoelectric coefficients of a two-phase piezoelectric/piezomagnetic composite, because the epoxy matrix is not stiff enough to transfer significant strains between the piezomagnetic and piezoelectric fibers.

During the production of agricultural commodities, an agricultural landscape is simultaneously being produced. In many regions, agriculture is no longer valued for just the production of food and fibre but also for the social, cultural and environmental amenities associated with the landscape. The paradigm of multifunctional agriculture has become concerned with the joint production of agricultural products and these rural amenities. The loss of agricultural land especially in areas around the urban-rural fringe has greatly affected the demand for these rural amenities. In response, governments and volunteer organizations have developed programs to preserve farmland. The Niagara Region is home to some of the best fruit growing land in Canada but has a long history of fighting to maintain its farmland. Drawing from the multifunctional paradigm, this study analyzes the preference for different rural amenities and farmland preservation in this unique region. Survey and interviews conducted with both the non-farm population and farmers indicated that demand exists for maintaining rural amenities and for farmland preservation. Consideration of these preferences will enhance the development of farmland preservation in the Niagara Fruit Belt.

During the production of agricultural commodities, an agricultural landscape is simultaneously being produced. In many regions, agriculture is no longer valued for just the production of food and fibre but also for the social, cultural and environmental amenities associated with the landscape. The paradigm of multifunctional agriculture has become concerned with the joint production of agricultural products and these rural amenities. The loss of agricultural land especially in areas around the urban-rural fringe has greatly affected the demand for these rural amenities. In response, governments and volunteer organizations have developed programs to preserve farmland. The Niagara Region is home to some of the best fruit growing land in Canada but has a long history of fighting to maintain its farmland. Drawing from the multifunctional paradigm, this study analyzes the preference for different rural amenities and farmland preservation in this unique region. Survey and interviews conducted with both the non-farm population and farmers indicated that demand exists for maintaining rural amenities and for farmland preservation. Consideration of these preferences will enhance the development of farmland preservation in the Niagara Fruit Belt.