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Articles 61 - 90 of 1117
Full-Text Articles in Chemistry
Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa
Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa
Journal of Materials Exploration and Findings
The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (pH₂S …
Expanding Tailored Nanomaterials With Precise Spatial And Morphological Control, Mengxue Zhang
Expanding Tailored Nanomaterials With Precise Spatial And Morphological Control, Mengxue Zhang
Theses and Dissertations
Multicomponent nanocomposites with precise spatial control are important for diverse fields spanning from energy conversion to optoelectronics and catalysis. Traditional methods using hydrophilic interactions alone are limited to random mixtures when multiple nanoparticle (NP) types are combined. To improve capabilities, a new strategy for polymer micelle design combining orthogonal hydrophilic (H) and fluorophobic (F) interactions to independently control two distinct NP populations was developed.
Initial research aimed at understanding F-interaction adjustments, which further enabled the switchability of FNP distribution states (dispersion vs aggregation) within polymer films through immersion annealing. Next, dual-NP assembly was examined using a diblock poly (H-b-F) where …
Computational Analysis Of Proton Conductivity Factors In Grotthuss-Style Mechanisms, Brock Dyer
Computational Analysis Of Proton Conductivity Factors In Grotthuss-Style Mechanisms, Brock Dyer
Physics and Astronomy Honors Papers
The mechanism and fundamental molecular properties involved in proton conduction are discussed. Four calculable properties are presented: the proton affinity, binding energy (between protonated and neutral forms), intramolecular tautomerization barrier, and proton hopping barrier. An overview of the computational methods used in this thesis, including an introduction to the many-body Schrödinger equation and Density Functional Theory, as well as a look at Plane-Wave Density Functional Theory and Gaussian-Type Orbital Density Functional Theory are presented. 4,5-dimethyl-[1,2,3]-triazole is used as a model system, with 10 variations being generated with varying amounts and positions of fluorine substitution on the methyl groups. Preliminary calculations …
Effects Of High Temperature Compaction On 3d Printed Carbon Fiber Reinforced Polymer Composites, John D. Barber
Effects Of High Temperature Compaction On 3d Printed Carbon Fiber Reinforced Polymer Composites, John D. Barber
Mechanical & Aerospace Engineering Theses & Dissertations
The aim of this dissertation was to study the effects of hot temperature compaction (HTC) upon the polymorphism and the mechanical behavior of an additively manufactured (AM), carbon fiber reinforced polyamide (PA6). Different pressure and temperature levels during HTC were tested to determine the overall effect upon the mechanical behavior and the material crystalline composition. Treated, carbon fiber reinforced PA6 samples were analyzed using differential scanning calorimetry, x-ray diffraction, thermogravimetric analysis, scanning electron microscopy, double cantilever beam testing and three-point bending testing. When considered with respect to as-printed samples, an HTC temperature of 190°C combined with 80 psi pressure resulted …
Solid-State Crystallization Of Zeolites And Their Use In Plastic Upcycling Applications, Yixin Liao
Solid-State Crystallization Of Zeolites And Their Use In Plastic Upcycling Applications, Yixin Liao
Doctoral Dissertations
Plastics have been an irreplaceable component of modern technology as well as everyday life. They have brought much convenience to us with their characteristics of great malleability, durability, and stability. The versatile and low-cost nature of plastics also enables their wide engagement in many modern industries including automobile, medical, communication as well as aerospace. Polyethylene (“PE”), made from polymerization of ethylene, is one of the most widely used plastics in the world. Being cheap, flexible, and long-lasting, they are extensively used in the packaging industry, especially for plastic bags and other sorts of containers. However, the durability of plastics, on …
Photo-Enhanced Output In Memdiode Devices Based On Hybrid Materials Open Access, Jacob Lee, Prabir Patra, Judy Fan
Photo-Enhanced Output In Memdiode Devices Based On Hybrid Materials Open Access, Jacob Lee, Prabir Patra, Judy Fan
Physics Faculty Research
The discovery of photo-enhanced outputs in the fabricated memdiodes based on metal halide-embedded polymeric hybrid composites has meaningful and practical implications. The two-terminal devices exhibit typical rectifying characteristics, similar to a standard pn junction diode, with unusual photo-enhanced charge transportation and hysteresis behaviors. The MDs consist of an active layer of blended organic–inorganic hybrid material [a mixture of CuCl2 and polyethylene glycol (PEG)] deposited on a layer of pure polymer (polymethyl methacrylate) and, in turn, on a rigid substrate (ITO glass or Si wafer). It is found that the photoinduced current increases hundreds of times in magnitude on the ITO …
Tailor-Designed Oxalic Acid-Crosslinked Poly(Vinyl Alcohol)/Chitosan Biodegradable Films For Active Food Packaging Applications, Reem Hazem Fathy Anwar Elaasar
Tailor-Designed Oxalic Acid-Crosslinked Poly(Vinyl Alcohol)/Chitosan Biodegradable Films For Active Food Packaging Applications, Reem Hazem Fathy Anwar Elaasar
Theses and Dissertations
Food packaging plastic waste is posing great threats to ecosystems, human health, and the planet's overall sustainability; therefore, research has been directed towards the fabrication of biodegradable food packaging materials. In this study, active and biodegradable oxalic acid (OA) crosslinked poly(vinyl alcohol) (PVA)/chitosan (CS) composite films of different weight ratios were synthesized via the solvent casting technique and their food packaging properties were investigated. Owing to its water resistance and antibacterial superiority, the composite film with the ratio of OA chemically crosslinked PVA/CS 80:20 was elected to be coated with green tea extract (GTE) to ameliorate its antibacterial and antioxidant …
Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter
Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter
Engineering Faculty Articles and Research
With the expanding use of polymers in additive manufacturing, sustainable resins for use in vat photopolymerization are required to reduce their environmental impact. One promising approach to achieve this is to incorporate biobased fillers that replace the acrylates in photopolymer resins as ‘green’ alternatives. In this study, photopolymer composites consisting of a methacrylate resin with varying calcium carbonate powder content between 0 and 50 wt.% were investigated. A digital light processing technique was used to fabricate tensile test specimens for mechanical testing. Good printability, dimensional accuracy, and good interlayer adhesion were observed for composite resin formulations that incorporated calcium carbonate …
Effect Of Single Screw Extrusion Process Parameters On Gel Formation And Properties In Polycaprolactone Films, Kitthanya Ritthichai
Effect Of Single Screw Extrusion Process Parameters On Gel Formation And Properties In Polycaprolactone Films, Kitthanya Ritthichai
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research focuses on the production of polycaprolactone (PCL) films using the commercial grade CAPA 6800 through a continuous single-screw extrusion process. This method serves as an alternative to conventional solution-based film fabrication that requires solvents and chemical reagents. The effects of processing temperature (80–120 °C), screw design (mixing screw and plain screw), and extruder-barrel cooling system (water-cooled and air-cooled) on film quality, gel formation, thermal properties, and mechanical properties of PCL films were investigated. Based on the processing of high-purity PCL pellets, the results indicate that the processing temperature, screw design, and barrel-cooling system did not affect the chemical …
การสังเคราะห์แกรฟีนควอนตัมดอตฐานกรดฮิวมิกและการประยุกต์เป็นสารเคลือบเซนเซอร์ตรวจจับความเครียด, ปริตตา จูฑาภักติ
การสังเคราะห์แกรฟีนควอนตัมดอตฐานกรดฮิวมิกและการประยุกต์เป็นสารเคลือบเซนเซอร์ตรวจจับความเครียด, ปริตตา จูฑาภักติ
Chulalongkorn University Theses and Dissertations (Chula ETD)
แกรฟีนควอนตัมดอต (GQDs) ถูกสังเคราะห์จากกรดฮิวมิก (HA) ที่เป็นสารตั้งต้นด้วยการใช้หม้อทอดไฟฟ้าด้วยวิธีไฮโดรเทอร์มอล ซึ่งในงานวิจัยนี้มุ่งเน้นการศึกษาตัวแปรที่เกี่ยวข้องกับกระบวนการสังเคราะห์ GQDs ด้วยการเปลี่ยนแปลงอัตราส่วนของกรดฮิวมิกที่ใช้สังเคราะห์และศึกษาผลของตัวโดป จากผลการศึกษาพบว่าตัวโดปที่ใช้ในการะบวนการสังเคราะห์ GQDs ที่เหมาะสมคือ เอทิลีนไดเอมีน (EDA) และจากผลการทดลองแสดงให้เห็นว่า GQDs ที่ใช้ EDA มีความเข้มแสงฟลูออเรสเซนต์สูงสุดที่ 66 หน่วยที่ความยาวคลื่น 467 นาโนเมตร (ช่วงแสงเขียวอมฟ้า) เมื่ออัตราส่วนกรดฮิวมิกต่อเอทิลีนไดอะมีนเท่ากับ 10 : 0.5 (มิลลิกรัม : มิลลิลิตร) ขนาดเฉลี่ยของอนุภาคอยู่ที่ 6.68 นาโนเมตร ซึ่งถูกวิเคราะห์โดยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องผ่าน และการวัดขนาดอนุภาค เทคนิคสเปกตรัมฟลูออเรสเซนซ์ และการดูดกลืนรังสี ตามลำดับ โครงสร้างกราฟิติกของ GQDs ถูกยืนยันด้วยสเปกโทรสโกปีรามาน ดังนั้นในงานวิจัยนี้จึงสนใจที่จะนำ GQDs ที่ใช้ EDA เป็นตัวโดปไปประยุกต์ใช้งานเป็นสารเคลือบเรืองแสงที่นำไปเคลือบลงบนยางซิลิโคนเพื่อนำไปประยุกต์ใช้เป็นสารเคลือบเซนเซอร์ตรวจจับความเครียด พบว่า ความเข้มของแสงฟลูออเรสเซนต์ของสารเคลือบเรืองแสง GQDs มีแนวโน้มลดลงเมื่อเวลาเวลาผ่านไป แต่สามารถหดกลับคืนใกล้เคียงสภาพเดิมเมื่อปล่อยการให้แรง และเมื่อเทียบค่าความเข้มของแสงฟลูออเรสเซนต์ของแต่ละอัตราส่วน พบว่า ที่อัตราส่วนกรดฮิวมิกต่อเอทิลีนไดอะมีนเท่ากับ 50 : 0.5 (มิลลิกรัม : มิลลิลิตร) มีค่าเข้มแสงของแสงฟลูออเรสเซนต์สูงที่สุด
การเตรียมคาร์บอนแบคทีเรียเซลลูโลสและควอนตัมดอตจากน้ำหมึกของหมึกกระดองสำหรับใช้งานตกแต่งสำเร็จสิ่งทอ, มณฑิชา สันติภาพมณฑล
การเตรียมคาร์บอนแบคทีเรียเซลลูโลสและควอนตัมดอตจากน้ำหมึกของหมึกกระดองสำหรับใช้งานตกแต่งสำเร็จสิ่งทอ, มณฑิชา สันติภาพมณฑล
Chulalongkorn University Theses and Dissertations (Chula ETD)
การพัฒนาวัสดุนาโนคาร์บอนและควอนตัมดอต เพื่อประยุกต์ใช้เป็นสารตกแต่งสำเร็จสิ่งทอเพื่อเพิ่มคุณสมบัติพิเศษ คาร์บอนนาโนไฟเบอร์และคาร์บอนควอนตัมดอตเป็นวัสดุนาโนที่มีสมบัติเด่นด้านความแข็งแรง การนำไฟฟ้า และการเรืองแสง ขอบเขตของงานวิจัยนี้ประกอบด้วยการเตรียม คาร์บอนนาโนไฟเบอร์จากแบคทีเรียเซลลูโลส (BC-CNF) และการสังเคราะห์ควอนตัมดอต (QDs) จากน้ำหมึกของหมึกกระดอง ซึ่งเป็นการสังเคราะห์ทางชีวภาพ ในส่วนของการเตรียม BC-CNF ได้มีการดัดแปรงโครงสร้างด้วยปฏิกิริยาซัลโฟเนต เพื่อให้ได้สาร BC-CNF-SO3- ซึ่งผลการวิเคราะห์ยืนยันการเกิดหมู่ฟังก์ชันซัลโฟเนต และอนุภาคในระดับซับไมครอน โดยมีขนาดอนุภาคเฉลี่ย 1.6218 ไมโครเมตร และสามารถกระจายตัวในน้ำได้ดี เมื่อนำ BC-CNF-SO3- มาตกแต่งสำเร็จบนผ้าพอลิเอสเทอร์ พบว่าความสามารถในการดูดซึมน้ำของผ้าเพิ่มขึ้น โดยผ้าที่ใช้ความเข้มข้นร้อยละ 3 ให้ประสิทธิภาพดีที่สุด ด้วยเวลาดูดซึมน้ำเฉลี่ยเพียง 2 วินาทีหลังการซัก ซึ่งแสดงถึงความคงทนต่อการซักที่ดี ในส่วนของการสังเคราะห์ QDs จากน้ำหมึกของหมึกกระดอง พบว่าอนุภาคมีขนาดอยู่ในช่วง 4-6 นาโนเมตร และแสดงความสามารถในการเรืองแสงภายใต้แสงอัลตราไวโอเลต โดยการเติมเอทิลีนไดเอมีน (EDA) ในปริมาณ 2 มิลลิลิตร ให้ค่าความเข้มของการเรืองแสงสูงสุด เมื่อนำ สารละลายควอนตัมดอตจากน้ำหมึกที่สังเคราะห์โดยเติมเอทิลีนไดเอมีน 2 มิลลิลิตร (EDA 2) ที่สังเคราะห์มาตกแต่งสำเร็จบนผ้าไนลอน พบว่าปริมาณ สารละลายควอนตัมดอตจากน้ำหมึกของหมึกกระดองที่สังเคราะห์โดยเติมเอทิลีนไดเอมีน 2 มิลลิลิตร (EDA 2) โดยใช้สารละลายปริมาตร 1 มิลลิลิตร ให้ความเข้มการเรืองแสงสูงสุด โดยก่อนซัก ค่าโดยประมาณ 180–190 a.u. และหลังซัก ค่าโดยประมาณ 110–120 a.u. โดยมีความคงทนต่อการซักดี ผลการวิจัยสรุปได้ว่า การประยุกต์ใช้ในการตกแต่งสำเร็จสิ่งทอ สามารถเพิ่มความสามารถในการดูดซึมน้ำของผ้าพอลิเอสเทอร์ และความสามารถในการเรืองแสงบนผ้าไนลอน
Development And Characterization Of Polysaccharide-Based Controlled Drug Delivery Platforms, Amanda Pepler
Development And Characterization Of Polysaccharide-Based Controlled Drug Delivery Platforms, Amanda Pepler
Open Access Dissertations
Drug delivery research focuses on overcoming challenges in patient treatment. Most therapeutics are delivered systemically through oral or intravenous routes. However, these administration methods are often inefficient due to therapeutic hydrophobicity, poor bioavailability, and liver metabolic clearance, necessitating frequent dosing. When treatment plans require frequent dosing, patients experience significant fluctuations in therapeutic concentration in the bloodstream, which can increase adverse side effects. These factors contribute to low patient compliance. Therefore, the core focus of drug delivery research is to develop new administration routes for therapeutics. Drug delivery systems (DDS) that can target therapeutics to a localized region offer advantages over …
Modified N-Heterocyclic Carbene Catalysts For Polyurethane Synthesis, Charise D. Young
Modified N-Heterocyclic Carbene Catalysts For Polyurethane Synthesis, Charise D. Young
Pomona Senior Theses
Polyurethanes are widely used polymers synthesized from diisocyanate and diol molecules. They are ubiquitous polymeric materials with important industrial applications. Their increasing market value prompts the need for selective and efficient production which can be achieved through N-Heterocyclic carbene (NHC) catalysis. N-heterocyclic carbenes are heterocyclic molecules containing a carbene atom and at least one nitrogen adjacent to the carbene center. The nitrogen substituents on the adjacent nitrogen play an important role in influencing their steric and electronic properties and resultant reactivity.1,2 There is a lack of a comprehensive understanding of the steric and electronic properties of NHCs and how …
Formation Of Pyramidal Palladium Enhanced By B(C₆F₅)₃ Additive Enabling Selective Alkene Monoisomerization, Paul D. Miller, Trandon A. Bender
Formation Of Pyramidal Palladium Enhanced By B(C₆F₅)₃ Additive Enabling Selective Alkene Monoisomerization, Paul D. Miller, Trandon A. Bender
Chemistry & Biochemistry Faculty Publications
The addition of a strong Lewis acid, tris(pentafluorophenyl)borane, facilitates the reduction of Pd(cod)Cl₂ with Et₃SiH to form palladium nanoparticles in organic solvents. It was found that these palladium nanoparticles are capable of selective monoisomerization of linear alkenes. This heterogeneous palladium catalyst is tolerant of a wide variety of functional groups, confirmed by substrate and robustness screenings. It is also possible to utilize poly(methylhydro)siloxane, an industrial waste byproduct, as the reductant to enable similar isomerization chemistry.
Individual And Collective Properties Of Tunable Photochemical Belousov-Zhabotinsky Micro-Reactors, Kudakwashe Benedict Shumba
Individual And Collective Properties Of Tunable Photochemical Belousov-Zhabotinsky Micro-Reactors, Kudakwashe Benedict Shumba
Graduate Theses, Dissertations, and Problem Reports (ETD)
Cell-like model chemical systems are powerful tools that can be used to explore the role of intercellular coupling on population level behaviors in communities of biological cells. Firstly, we present a new method for fabricating such micro-reactors using the photosensitive Belousov–Zhabotinsky (BZ) reaction system employed in silica microparticles. These BZ micro-reactors have a tunable response to photochemical coupling, varying from a fully excitatory response to a fully inhibitory response. Their response can be tuned through variations in either the reactive mixture or, on an individual micro-reactor level, by changes in the synthesis temperature used during the fabrication of the silica …
Polybenzodiazine Aerogels: All-Nitrogen Analogues Of Polybenzoxazines - Synthesis, Characterization, And Their Application In Carbon Dioxide Capture, Vaibhav Edlabadkar
Polybenzodiazine Aerogels: All-Nitrogen Analogues Of Polybenzoxazines - Synthesis, Characterization, And Their Application In Carbon Dioxide Capture, Vaibhav Edlabadkar
Doctoral Dissertations
"The rapidly risen concentration of carbon dioxide in the atmosphere over recent years contributed to global warming and ocean acidification. Carbon capture is viewed as an essential tool from keeping atmospheric CO2 levels from rising further. This thesis focuses on the development of new materials for high capacity and selective adsorption of CO2. One such material was based on a newly synthesized tetrahydroquinazoline (THQ), which was designed as an all-nitrogen analogue of main-stream benzoxazine monomers. THQ solutions in DMF gelled at 100 °C via HCl-catalyzed ring opening polymerization to polybenzodiazine (PBDAZ) wet gels, which were dried in …
Characterization And Optimization Of Sand And Tung Oil-Based Resins For Binder-Jet 3d Printing, Daniel I. Ajiola
Characterization And Optimization Of Sand And Tung Oil-Based Resins For Binder-Jet 3d Printing, Daniel I. Ajiola
College of Graduate Studies: Theses & Dissertations
Binder-jet 3D printing as a transformative technology in additive manufacturing, offers the ability to fabricate complex structures with diverse materials. This thesis investigates the use of a sustainable tung oil-based resin to create composites, exploring the potential for an eco-friendly alternative to synthetic binders.
The aim of this research is to develop and characterize a bio-based resin formulation, using tung oil as the primary binder, for application in binder-jet 3D printing with sand as the reinforcement. The resin formulation was prepared by combining tung oil, n-butyl methacrylate, divinylbenzene, and di-tert-butyl peroxide in precise proportions, ensuring a balanced mixture that supports …
Single-Step Synthesis Of Activated Carbon From Arabica Spent Coffee Ground Using K2co3 As Activator Agent, Ghina Ivana Mieldan, Yuliusman Yuliusman
Single-Step Synthesis Of Activated Carbon From Arabica Spent Coffee Ground Using K2co3 As Activator Agent, Ghina Ivana Mieldan, Yuliusman Yuliusman
Journal of Materials Exploration and Findings
Activated carbon is a nanomaterial that is often used as an effective adsorbent. Activated carbon raw materials can use biomass, such as coffee grounds, which can be found along with the growth of public interest in coffee drinks. Chemical activators are used for activation to increase biomass carbon's adsorption capacity. Using K2CO3 activator to increase the specific surface area of activated carbon is more harmless than KOH. The use of spent coffee grounds as carbon source and food additive K2CO3 as an activator can make food-grade activated carbon that can be used for food. …
Effect Of Alkyd And Polyester Resin Compositions On Corrosion Resistance, Blistering, And Adhesion In Utilization Of Oily Sludge As Anti-Rust Coating Material, Gerets Land Kakalang, Yohanes David Kristianto, Johny Wahyuadi Mudaryoto
Effect Of Alkyd And Polyester Resin Compositions On Corrosion Resistance, Blistering, And Adhesion In Utilization Of Oily Sludge As Anti-Rust Coating Material, Gerets Land Kakalang, Yohanes David Kristianto, Johny Wahyuadi Mudaryoto
Journal of Materials Exploration and Findings
Oil sludge is a waste derived from upstream and downstream activities of the oil and gas industry which is estimated at 10,000 tonnes generated from all PERTAMINA downstream activities spread across various fields, processing units and depots throughout Indonesia. Oil sludge has the same characteristics as asphalt, where asphalt in previous studies can be used as an anti-rust coating, so that the handling of oily sludge can be topped up by reusing and having its own added value. The purpose of this research is to utilise waste oily sludge as an alternative anti-rust coating material and compare alkyd resin and …
Establishment Of Structure-Property-Processing Relationships For Design Of Sprayable Hydrogels And Amyloid/Peo Electrospun Composites, Xianjun Wang
Dissertations
The focus of this dissertation is the design, synthesis, characterization, and prototyping of bio-inspired materials to understand the role of structure, intermolecular interactions, and processing technique on the self-assembly, bioactive properties, and mechanical properties of the biomaterials. This work is divided into three research areas: 1) sprayable and adhesive glycopolymer based hydrogels; 2) decapeptide-based composite nanofiber mats; and 3) prototyping sutures and meshes via electrospinning. The established structure-property-processing relationships provide a foundation for designing biomaterials in the future.
The first chapter provides an introductory overview of the requirements necessary for the development of hydrogels, glycopolymers, and peptides, including relevant processing …
Investigation Of Polybenzoxazine Vitrimers Based On Dynamic Transesterification Exchange, Jaylen Davis
Investigation Of Polybenzoxazine Vitrimers Based On Dynamic Transesterification Exchange, Jaylen Davis
Dissertations
With the ever-increasing issue of plastic waste production, a greener approach to synthetic processes and increased sustainability in plastic materials is still a high demand. Thermosets, which find uses in applications such as coatings, adhesives, and aerospace composites account for 15% of global plastics production, are particularly problematic in this context, as covalent crosslinks within the material serve both as a source of high-performance stability during use and as a barrier to conventional recycling after use. Therefore, our efforts focus on the incorporation of dynamic transesterification exchange chemistry into polybenzoxazine thermosets, which allows these materials to undergo reprocessing. This investigation …
Composites Developed By The Reaction Of Elemental Sulfur With Biologically Derived Fats And Oils, Katelyn Tisdale
Composites Developed By The Reaction Of Elemental Sulfur With Biologically Derived Fats And Oils, Katelyn Tisdale
All Dissertations
Human civilization’s modern infrastructure relies mainly on cement and petrochemical products. However, the production of these building materials have harmful ecological effects such as green gas emissions, therefore intensifying the need to develop alternative, sustainable structural materials from renewably sourced or waste material precursors. The work presented herein investigates various biomass derived resources that serve as the olefin source for reaction with elemental sulfur, another abundant waste source, via inverse vulcanization to form high strength composites competitive with that of traditional building materials.
Chapter one reviews various techniques that have been developed and executed in an effort towards lignin valorization …
Influence Of Glycopolymer Structure On Amphiphilic, Hybrid, Linear Branched Block Copolymer Properties For Use In Biomedical Applications, Kevin Green
Dissertations
The focus of this dissertation is evaluating and adding fundamental knowledge regarding the structure-property relations of glycopolymers used in the design of hybrid block copolymers (HBC) that are cable of self-assembling into delivery vehicles for biomedical applications. A shift to the utilization of natural materials in the design and fabrication of drug-delivery vehicles has garnered significant attention. Understanding the effects of linear glycopolymers content and composition on the resulting HBCs properties can provide valuable insight into how these materials may be tailored for use in targeted biological applications.
The first chapter introduces current literature on the need for improvement in …
Evaluation Of Polymerization Condition Reactions Of Methyl Vinyl Ketone For Hydrogen Storage, Rituborna Ghosh
Evaluation Of Polymerization Condition Reactions Of Methyl Vinyl Ketone For Hydrogen Storage, Rituborna Ghosh
Theses and Dissertations
Hydrogen is widely regarded as one of the most promising clean alternative fuel sources; however, its widespread adoption has been hindered by significant challenges related to storage and transportation. Various storage methods have been proposed and developed, with continuous advancements being made to address these issues. Among the most effective solutions is the utilization of polymers, which serve as safe and efficient hydrogen storage media. This work investigated the polymerization of methyl vinyl ketone using different ratio of monomer: initiator and monomer: crosslinker using N,N′-methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator in a free radical polymerization mechanism. …
Recyclable Composites Prepared From Animal Coproducts And Industrial Waste Sulfur, Perla Y. Sauceda-Oloño
Recyclable Composites Prepared From Animal Coproducts And Industrial Waste Sulfur, Perla Y. Sauceda-Oloño
All Dissertations
Pursuing sustainable and environmentally friendly materials has become a significant objective in materials science, particularly flame retardants and construction materials. This dissertation explores the development and evaluation of novel composites and high sulfur-content materials (HSMs) as potential alternatives to conventional, environmentally harmful materials.
Chapter one reviews recent advancements in environmentally benign flame-retardant additives, highlighting the potential of bio-derived phenols, polysaccharide derivatives, and greener phosphorus sources. The review discusses how green additives can enhance the flame retardancy, thermal stability, and smoke suppression properties of various polymers while addressing the challenges and future directions in the field.
Chapter two investigates the production …
Synthesis Of Photocleavable Molecules For Neurological Applications, Nishal Madujith Egodawaththa Arachchilage Don
Synthesis Of Photocleavable Molecules For Neurological Applications, Nishal Madujith Egodawaththa Arachchilage Don
Theses and Dissertations
In recent biomedical research, the precise control of molecular dynamics through light activation has emerged as a powerful tool, particularly in the field of neurobiology. This approach involves the use of photocleavable cages or photoprotective groups (PPGs) that are chemically tethered to biologically active molecules such as neurotransmitters or calcium chelators. These cages remain inert until exposed to specific wavelengths of light, typically in the visible range, triggering the release of the active compound with high spatiotemporal precision.
For neurotransmitter systems, such as glutamate (Glu), which plays a critical role in synaptic transmission and memory formation, researchers have developed novel …
Solubility Characterization Of Organic Molecules For Aqueous Organic Redox Flow Batteries, Anthony W. Ferrell, Harkeerith K. Vij, Seamus D. Jones
Solubility Characterization Of Organic Molecules For Aqueous Organic Redox Flow Batteries, Anthony W. Ferrell, Harkeerith K. Vij, Seamus D. Jones
College of Engineering Summer Undergraduate Research Program
The major obstacle to renewable energy sources is a lack of long-term energy storage capabilities. Energy produced during the day dissipates, leaving insufficient electricity for at night. The goal of the project is to design an Aqueous Organic Redox Flow Battery (AORFB) to act as long-term energy storage. Work has been done using machine learning to identify suitable compounds for the batteries. In this work there was no indication as to the aqueous solubility of the molecules; this controls the device’s energy storage capabilities. We used a machine learning model to determine the aqueous solubility of slightly more than 3000 …
The Conservation Treatment And Technical Study Of Two Marisol Sculptures, Ruthie Rolfsmeyer
The Conservation Treatment And Technical Study Of Two Marisol Sculptures, Ruthie Rolfsmeyer
Art Conservation Master's Projects
ABCDEFG & Hi (1961-62) and Father Damien (1966-67) are both painted wooden sculptures created by Marisol during the height of her fame. Although Marisol is a well-known artist, whose fame has been rekindling since her death in 2016, there have been few technical studies of her works. Multimodal imaging and scientific analysis of these two sculptures provide insight into their structure and materials. Techniques include x-ray radiography, reflectance transformation imaging, x-ray fluorescence spectroscopy, Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography-mass spectrometry. Key findings include the identification of toolmarks, nitrocellulose, alkyd, and acrylic paints, and a genuine diamond and pearl in …
Elevating Commodity Polymers To Advanced Applications In Polymer Photonics And Polymer-Derived Porous Materials, Mark Robertson
Elevating Commodity Polymers To Advanced Applications In Polymer Photonics And Polymer-Derived Porous Materials, Mark Robertson
Dissertations
Since the inception of synthetic polymers, polymer-derived materials have permeated into essentially all aspects of our daily lives. The most commonly thought of examples of polymer materials involve single-use, disposable products to increase shelf lives of perishable items, act as personal protective equipment, or provide some degree of convenience for the consumer. However, as we have furthered our understanding of polymer chemistry and polymer physics to develop increasingly sophisticated polymer systems, polymer materials have been employed in incredibly advanced applications. These include solid electrolytes for energy storage, matrices for aerospace grade carbon fiber-reinforced composites, membranes for liquid and gas separations, …
Chemical Recycling Of Bio-Based Polyurethane Foams: Evaluating Bio-Based Glycols In Comparison To Petroleum-Based Glycols, Anirudh Thorbole Mr.
Chemical Recycling Of Bio-Based Polyurethane Foams: Evaluating Bio-Based Glycols In Comparison To Petroleum-Based Glycols, Anirudh Thorbole Mr.
Electronic Theses & Dissertations
The paradigm shift towards bio-based polyurethane foams (bio-PUF) has significantly increased post-consumer waste. To address this issue, this research represents a novel approach to enhance sustainable development in the recycling industry by replacing traditional petroleum-based glycols with sustainable bio-based alternatives. This study explores the glycolysis of bio-PUF using bio-based SG-522 glycol and polyethylene glycol (PEG) for comparison. The findings from this research as outlined, reveal no significant differences in depolymerization time between the two glycols, achieving proper depolymerization and high recovery yields of over 95% after solvent purification. Comprehensive FT-IR and NMR analyses confirmed the successful degradation of bio-PUF and …