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Articles 301 - 330 of 1118
Full-Text Articles in Chemistry
Targeted Combination Therapy Of Nsclc Using Taxol And Fingolimod Loaded Nanoceria, Raghunath Narayanam
Targeted Combination Therapy Of Nsclc Using Taxol And Fingolimod Loaded Nanoceria, Raghunath Narayanam
Electronic Theses & Dissertations
Among various types of cancers, lung cancer reports highest death rate and Non-Small cell lung cancer causes highest mortality in lung cancers. This is mainly due to the scarcity of treatment options and the available treatment shows numerous adverse effects. In the recent times, nanotechnology paved a new path for the diagnosis and therapy of cancer. In this study, we worked on a novel, multifunctional nanoceria (NC) platform loaded with two unique drugs taxol and fingolimod, which acts in their own ways providing synergic therapeutic effect. We hypothesized that the usage of the polyacrylic acid (PAA) coated nanoceria (PNC) increases …
Environment-Friendly Flame Retardants For Bio-Based Polyurethanes, Felipe Martins De Souza
Environment-Friendly Flame Retardants For Bio-Based Polyurethanes, Felipe Martins De Souza
Electronic Theses & Dissertations
Finding alternative ways to decrease the large consumption of non-renewable resources has been one of the greatest challenges faced by the industry and academia. The trend of using bio-renewable-based materials is an interesting alternative to tackle environmental issues as well as provide economically viable materials. In this work, carvone, an essential oil, was used to synthesize a bio-based polyol through a thiol-ene reaction. The chemical functions were analyzed through Fourier transformed infrared spectrum (FTIR), gel permeation chromatography (GPC), viscosity, and hydroxyl number, which confirmed the synthesis of carvone-based polyol. The latter was then physically blended with three different flame-retardants separately: …
End Group Modification Of Linear Dendritic Block Copolymers (Ldbcs), Chinwe Udemgba
End Group Modification Of Linear Dendritic Block Copolymers (Ldbcs), Chinwe Udemgba
Honors Theses
Linear dendritic block copolymers are amphiphilic molecules that consist of a dendritic hydrophilic portion and a linear hydrophobic portion. Its unique ability to self-assemble into spherical nanoaggregates while having the potential to uptake and transport both hydrophilic and hydrophobic drugs makes these polymers an item of interest in regard to the drug delivery field. The synthesis of polyamidoamine-polylactide linear dendritic block copolymers was designed to address the common issues in drug delivery systems, including problems in permeability, solubility, stability, specificity, and retention. Though this linear dendritic block copolymer has previously been synthesized in our lab with cationic amine surface functionalities, …
Synthesis And Self-Assembly Of Amphiphilic Block Copolymers For The Fabrication Of Non-Spherical Polymersomes, Tamuka Chidanguro
Synthesis And Self-Assembly Of Amphiphilic Block Copolymers For The Fabrication Of Non-Spherical Polymersomes, Tamuka Chidanguro
Dissertations
Polymersomes, also known as polymer vesicles, have gained a lot of interest over the past two decades. These hollow spherical systems are made via the self-assembly of amphiphilic block copolymers and have found use in a range of areas from drug delivery, to cellular models, to nanoreactors. Their hollow nature allows them to carry hydrophilic cargo in their inner compartment and hydrophobic cargo in their membrane. Over the last decade, increasing efforts have focused on controlling the morphology of polymersomes. Research has shown that polymersome morphology plays an important role for instance in drug delivery, where tubular or rod-like vesicles …
Design And Modeling Of Bioinspired Polyelectrolytes With Controlled Architectures For Gene Delivery Applications, Kelli Stockmal
Design And Modeling Of Bioinspired Polyelectrolytes With Controlled Architectures For Gene Delivery Applications, Kelli Stockmal
Dissertations
This dissertation focuses on the development of a range of bioinspired polyelectrolytes with controlled architectures for gene and drug delivery applications. Glycans are ubiquitous in biological systems, and understanding the role of saccharide stereochemistry, as well as cationic charge, on polymer behavior in aqueous solution and the interactions with nucleic acids can provide insight into how synthetic polyelectrolytes can be used for non-viral gene delivery and other biological applications. The first chapter provides an introductory overview on how cationic polyelectrolytes can be used to aid the delivery of RNA for controlling gene expression in a variety of cell types, how …
Atomic Oxygen Resistant Low Earth Orbit Stable Polymer Matrix Composites Employing Phenylphosphine Oxide Epoxy-Amines, Witold Fuchs
Atomic Oxygen Resistant Low Earth Orbit Stable Polymer Matrix Composites Employing Phenylphosphine Oxide Epoxy-Amines, Witold Fuchs
Dissertations
Atomic oxygen (AO) attacks polymer matrix composites (PMC’s) on the surfaces of spacecraft in low earth orbit (LEO) and threatens safe spacecraft operation and service life. Incorporating phenylphosphine oxide (PPO) groups into polymer chains offers a self-regenerating method of protection from AO but remains poorly understood. Herein, epoxies containing PPO groups were synthesized with increasing concentrations of phosphorus [P] from 0 to 8 wt % to investigate their AO resistance. Measurements confirmed the exposure of these materials to AO produces a passivation phosphate (POx) layer on the surface of the sample and the efficacy of the resultant layer was directly …
Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza
Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza
Open Access Theses & Dissertations
The following body of work encompasses the synThesis, upscaling, additive manufacturing, and characterization of microspheres as functional fillers incorporated into polymer syntactic foams. Synthesizing microspheres permits control over morphology, dispersion of particles, and size while the use of direct write manufacturing allowed for the controllability of filler orientation. Two different syntactic foams were developed from similar methodologies: (1) a silicone syntactic foam (2) epoxy syntactic foam. The silicone epoxy foam showed an increasing in damping and elastic modulus. The epoxy syntactic foams showed an enhanced thermal and electrical properties.
Development Of Biomaterials For Drug Delivery, Raquel De Castro
Development Of Biomaterials For Drug Delivery, Raquel De Castro
Graduate Theses and Dissertations
Drug delivery systems (DDS) have highly evolved in the last decades with the development of hydrogels and nanoparticles. However, high systemic uptake, side effects, low bioavailability, and encapsulation efficiency continue to be a major hurdle faced by such DDSs.
Nanoparticles and hydrogels can be specifically designed for targeted DDSs to mitigate some of the problems. This dissertation aimed to design two DDSs for ocular drug delivery and one for cancer treatment. The first project sought to develop chitosan nanoparticles (Cs-NP) using PEGDA as a copolymer to encapsulate gentamicin (GtS) for ocular drug delivery. Cs-NPs contain positive charges that can interact …
A Conductivity Analysis Of A Newly Synthesized Poly(Ethylene Glycol) Methyl Ether Hydroxide Electrolyte, Sarah Marie Peterson
A Conductivity Analysis Of A Newly Synthesized Poly(Ethylene Glycol) Methyl Ether Hydroxide Electrolyte, Sarah Marie Peterson
Honors Theses
This thesis investigates the synthesis and conductive properties of a Poly (ethylene glycol) methyl ether-based polymer electrolyte. The goal of the synthesis is to enhance the hydroxide ion conduction properties of the polymer with its cationic groups attached. The MePEG backbone contained seven ethylene glycol groups and was modified to substitute the hydroxide group in the MePEG with trimethylamine. In addition, the bromide added in the synthesis was exchanged for hydroxide ions to allow for the transportation of hydroxide ions in polymeric electrolytes that can be used in Anion Exchange Membrane Fuel Cells. The newly synthesized polymer was compared to …
Synthesis And Conductivity Analysis Of A Methyl (Polyethylene Glycol) Comb Polymer, Olivia Fox
Synthesis And Conductivity Analysis Of A Methyl (Polyethylene Glycol) Comb Polymer, Olivia Fox
Honors Theses
The overall goal of work in this field is to improve materials for use in a variety of applications in fuel cell and battery production. This thesis specifically investigates the synthesis of two variations of a methyl (polyethylene glycol) comb polymer electrolyte (MePEGnwhere n=7) to understand how the molecular structure of an ion-conducting polymer affects its electrochemical properties. The MePEG used in this synthesis contains seven ethylene glycol groups and was added to a poly (methylhydrosiloxane) comb polymer backbone. In the first sample, the polymer contained only the MePEG sidechain, and in the second sample, the polymer contained …
Thermal, Mechanical, And Rehealing Properties Of Cross-Linked Ionene Networks, Katelyn Lindenmeyer
Thermal, Mechanical, And Rehealing Properties Of Cross-Linked Ionene Networks, Katelyn Lindenmeyer
Honors College Theses
Polymers which contain ionic liquid groups have numerous applications in a wide variety of fields. Past research from our group has shown that IL-containing polymers which exist in covalently crosslinked networks can exhibit good ionic conductivities despite the hindrance in polymer chain mobility and relaxation. In part one of this thesis, efforts to create ionic networks which have the capability of being rehealed after exposure to an external stimulus are discussed. Thermoreversible maleimide-furan chemistry was incorporated into an imidazolium-containing ionene network. Maleimide-terminated, imidazolium-containing monomers were coupled with furan-functionalized monomers, prepared from commercially available multifunctional acrylates. Thermal, mechanical and rheological characterization …
Effect Of Precise Control Of Crosslink Density On The Thermal, Mechanical, And Conductive Properties Of Covalently Crosslinked Ionene Networks, Alexander Thome
Effect Of Precise Control Of Crosslink Density On The Thermal, Mechanical, And Conductive Properties Of Covalently Crosslinked Ionene Networks, Alexander Thome
Honors College Theses
Ionic liquids (ILs), besides being well known as environmentally friendly solvents, have attracted attention for a wide variety of other applications, including gas separation, 3D-printing and electrochemical actuators. However, for many such applications, incorporation of the IL moiety into a polymeric material eliminates the use of mechanically unstable free ILs while maintaining many of their electrochemical benefits. Such polymers can take two basic forms: poly(ionic liquid)s are ion-containing polymers in which the IL group is attached pendant to the polymeric backbone, while ionenes are ion-containing polymers in which the IL group is anchored directly into the backbone of the repeating …
Nitro Group Reduction For Use In Organic, Cathodic Materials, Brock G. Goeden
Nitro Group Reduction For Use In Organic, Cathodic Materials, Brock G. Goeden
Honors Thesis
The industrial demand for higher capacity, light-weight battery materials has skyrocketed in recent years due to heavy investments in portable electronics, electronic vehicles, and renewable energy sources. However, rechargeable battery technology has seen little improvement since the invention of the Lithium-Ion battery in the 1980s. The low energy density of the traditionally utilized LiCoO2 cathodic material (specific capacity: 272 mAh g-1), has limited its potential to meet these increasing demands. To solve this problem, our research group is investigating new types of lightweight, organic, polymeric materials with conductive backbones as a possible replacement for the cathodic materials in Lithium-Ion batteries. …
Characterization, Immobilization, And Polymer Related Applications Of Watermelon Seed Powder, A Practical Source Of Urease Enzyme, Anthony Quan Quoc Mai
Characterization, Immobilization, And Polymer Related Applications Of Watermelon Seed Powder, A Practical Source Of Urease Enzyme, Anthony Quan Quoc Mai
LSU Doctoral Dissertations
Urease enzyme was crystallized almost a century ago, and to this day its intrinsic stability is not ideal for everyday applications. This work introduces a new process by which a naturally encapsulated material, watermelon seed powder (WMSP), is characterized for its stability and activity. WMSP enzymatic activity has been measured for over a year at various storage conditions—exposed to ambient atmosphere for a year, WMSP retained above 90% activity. In aqueous conditions, the enzyme maintained above 60% activity after two months; with the addition of a preservative that number stays at about 90%. There is a pH shift of the …
An Investigation Of Cross-Links On Crystallization And Degradation In A Novel, Photocross-Linkable Poly (Lactic Acid) System, Nicholas Baksh
An Investigation Of Cross-Links On Crystallization And Degradation In A Novel, Photocross-Linkable Poly (Lactic Acid) System, Nicholas Baksh
USF Tampa Graduate Theses and Dissertations
Polymeric molecular structure consists of repeating units bonded together. Mechanicalproperties can be altered without affecting chemical makeup by altering the number of these units. Small molecules can be introduced and/or polymers can be modified to form bonds between molecular chains. Cross-linking, as this is called, also introduces mechanical variation with minimal effects on chemical composition. Lastly, polymer chains reorient themselves in response to intermolecular forces. This temperature dependent response is known as crystallization. Although chemistry is unaltered, mechanical properties can depend highly on the percent of the sample that is crystallized.
Cross-linking is known to enhance the mechanical properties of …
Application Of Zwitterions In Forward Osmosis: A Short Review, Yu-Hsuan Chiao, Arijit Sengupta, Micah Belle Marie Yap Ang, Shu-Ting Chen, Teow Yeit Haan, Jorge Almodovar, Wei-Song Hung, S. Ranil Wickramasinghe
Application Of Zwitterions In Forward Osmosis: A Short Review, Yu-Hsuan Chiao, Arijit Sengupta, Micah Belle Marie Yap Ang, Shu-Ting Chen, Teow Yeit Haan, Jorge Almodovar, Wei-Song Hung, S. Ranil Wickramasinghe
Chemical Engineering Faculty Publications and Presentations
Forward osmosis (FO) is an important desalination method to produce potable water. It was also used to treat different wastewater streams, including industrial as well as municipal wastewater. Though FO is environmentally benign, energy intensive, and highly efficient; it still suffers from four types of fouling namely: organic fouling, inorganic scaling, biofouling and colloidal fouling or a combination of these types of fouling. Membrane fouling may require simple shear force and physical cleaning for sufficient recovery of membrane performance. Severe fouling may need chemical cleaning, especially when a slimy biofilm or severe microbial colony is formed. Modification of FO membrane …
Development Of Engineered Soil Surrogates For Modeling Natural Soil Sorption Behavior, Ghada Yehia Abdalla
Development Of Engineered Soil Surrogates For Modeling Natural Soil Sorption Behavior, Ghada Yehia Abdalla
LSU Doctoral Dissertations
The land produces more than 95% of the global food supply, and with a continuously growing population, we need to optimize the use of the available agricultural land. Soil organic matter (SOM) is an essential component of soils, especially concerning their fertility and sorption behavior. The chemical composition of the SOM consists of lipids, lignin, and cellulose. However, the heterogeneous and complex nature of SOM, and real soils, makes their study challenging and introduces uncontrollable factors.
Therefore, structural mimics of natural soils with increasing complexity representing the real soil functionality were synthesized and evaluated for bulk properties related to their …
Polyesters With Main And Side Chain Phosphoesters As Structural Motives For Biocompatible Electrospun Fibres, André E. Polloni, Viviane Chiaradia, Ronaldo José F.C. Do Amaral, Cathal Kearney, Brian Gorey, Débora De Oliveira, José V. De Oliveira, Pedro H.H. De Araújo, Claudia Sayer, Andreas Heise
Polyesters With Main And Side Chain Phosphoesters As Structural Motives For Biocompatible Electrospun Fibres, André E. Polloni, Viviane Chiaradia, Ronaldo José F.C. Do Amaral, Cathal Kearney, Brian Gorey, Débora De Oliveira, José V. De Oliveira, Pedro H.H. De Araújo, Claudia Sayer, Andreas Heise
Articles
Phosphoester containing polymers are promising materials in biomedical applications due to their biocompatibility and biodegradability. Utilising thiol-ene chemistry, the synthesis of two novel structural polymer motives combining polyesters and phophoester groups was explored. The first polymer was obtained by coupling ene-functional poly(thioether-phosphoester) with thiol functional poly(pentadecalactone). While the coupling reaction was successful, yields remained low presumably due to inadequate endgroup stoichiometry. The second polymer comprised phosphoester side groups conjugated to unsaturated poly(globalide). Double bond conversions up to 84% were achieved depending of the type of phosphoester thiol and relative reactant ratios. The resulting polymers transitioned from solid semicrystaline to liquid …
Degradation Of Natural And Synthetic Fibers In Various Aqueous Environments, Jaylin Bryant
Degradation Of Natural And Synthetic Fibers In Various Aqueous Environments, Jaylin Bryant
Honors Scholars Collaborative Projects
Fabrics are one variant of polymers, macromolecules that form the foundation of our society. They consist of small subunits called monomers, which are covalently bonded together and layered over each other through intermolecular attractions. There are natural fabrics, such as cotton and silk, and synthetic fabrics like polyester and rayon. Scientists in forensic taphonomy study postmortem changes made to human remains, which can also include clothes found at the scene. In this study, the degradation rates of four white fabrics (cotton, polyester, rayon, and silk) were observed in various aqueous environments (pure, chlorinated, sea, and lake) in order to observe …
Effects Of Resin Chemistries On The Selective Removal Of Industrially Relevant Metal Ions Using Wafer-Enhanced Electrodeionization, Humeyra B. Ulusoy Erol, Christa N. Hestekin, Jamie A. Hestekin
Effects Of Resin Chemistries On The Selective Removal Of Industrially Relevant Metal Ions Using Wafer-Enhanced Electrodeionization, Humeyra B. Ulusoy Erol, Christa N. Hestekin, Jamie A. Hestekin
Chemical Engineering Faculty Publications and Presentations
Wafer-enhanced electrodeionization (WE-EDI) is an electrically driven separations technology that occurs under the influence of an applied electric field and heavily depends on ion exchange resin chemistry. Unlike filtration processes, WE-EDI can be used to selectively remove ions even from high concentration systems. Because every excess ion transported increases the operating costs, the selective separation offered by WE-EDI can provide a more energy-efficient and cost-effective process, especially for highly concentrated salt solutions. This work reports the performance comparison of four commonly used cation exchange resins (Amberlite IR120 Na+, Amberlite IRP 69, Dowex MAC 3 H+, and …
Design, Synthesis And Applications Of Nanoparticles In Suppression Of Mosquito-Born Flaviviridae Viruses, Maria R. Blahove
Design, Synthesis And Applications Of Nanoparticles In Suppression Of Mosquito-Born Flaviviridae Viruses, Maria R. Blahove
College of Graduate Studies: Theses & Dissertations
Recently, nanoparticles have become an origin of exploration in the chemistry field due to their unique medical uses. The current drug delivery models of nanoparticles often include a metal base with a drug conjugated to its surface. However this raises concerns regarding toxicity. A novel approach to solving this dilemma is the development of nanosized biocompatible polymer-based micelles, created from PEG-PCL-PEG triblock polymer, and formed around a drug of choice. The goal is to create a drug carrier nanoparticle system that is labile at a specific intracellular pH, without undue toxicity to the cell. This creates a drug-loaded nanoparticle that …
Hydroamidation With Acetamides And Trifluoroacetamides, Gordon H. Whitetree
Hydroamidation With Acetamides And Trifluoroacetamides, Gordon H. Whitetree
College of Graduate Studies: Theses & Dissertations
The hydroamidation reaction is an attractive methodology for the construction of larger functional molecules. In our research, a baseline reactivity was established for the hydroamidation reaction using a set of N-alkyl and N-aryl (trifluoro)acetamides with methyl acrylate and acrylonitrile, various bases and varying reaction conditions. The combination of alkenes, acetamides, and trifluoroacetamides with base was crucial for reaction rate. N-aryl trifluoroacetamides exhibited near quantitative conversions in neat alkene with Diazabicycloundecene (DBU) as base. The less acidic N-aryl acetamides performed much faster in the presence of KOtBu and conversions of >95% were accomplished regularly but contained a large presence …
นาโนคอมพอสิตของยางธรรมชาติอิพอกซิไดส์/นาโนเซลลูโลสสกัดจากผักตบชวา, ชุติเดช ทองดีเลิศ
นาโนคอมพอสิตของยางธรรมชาติอิพอกซิไดส์/นาโนเซลลูโลสสกัดจากผักตบชวา, ชุติเดช ทองดีเลิศ
Chulalongkorn University Theses and Dissertations (Chula ETD)
ในงานวิจัยนี้ได้เตรียมนาโนคอมพอสิตของยางธรรมชาติอิพอกซิไดส์/นาโนเซลลูโลส โดยเริ่มจากการสังเคราะห์ยางธรรมชาติอิพอกซิไดส์ผ่านกระบวนการอิพอกซิเดชันของน้ำยางธรรมชาติ พบว่ามีปริมาณหมู่อิพอกไซด์ร้อยละ 31 โดยโมล ต่อมาทำการเตรียมนาโนเซลลูโลสจากผักตบชวาโดยเตรียมเซลลูโลสนาโนไฟเบอร์ และเซลลูโลสนาโนคริสตัลจากการไฮโดรไลซิสเซลลูโลสนาโนไฟเบอร์ด้วยกรดที่ความเข้มข้นต่าง ๆ จากการวิเคราะห์โครงสร้างผลึกพบว่าเซลลูโลสนาโนคริสตัลมีปริมาณผลึกมากกว่าเซลลูโลสนาโนไฟเบอร์ และปริมาณผลึกเพิ่มขึ้นเมื่อเพิ่มความเข้มข้นของกรดมากขึ้น และเมื่อทำการเตรียมนาโนคอมพอสิตของยางธรรมชาติอิพอกซิไดส์/นาโนเซลลูโลส พบว่าการใส่นาโนเซลลูโลสมีส่วนช่วยในการปรับปรุงสมบัติด้านความทนแรงดึงและความทนน้ำมันของนาโนคอมพอสิตเมื่อเทียบกับยางธรรมชาติและยางธรรมชาติอิพอกซิไดส์ หากแต่เสถียรภาพทางความร้อนของนาโนคอมพอสิตไม่มีการเปลี่ยนแปลง ซึ่งจากการเตรียมนาโนคอมพอสิตของยางธรรมชาติอิพอกซิไดส์/เซลลูโลสนาโนไฟเบอร์ (ปริมาณ 0.5–3 ส่วนต่อยางร้อยส่วน) พบว่านาโนคอมพอสิตที่ใส่เซลลูโลสนาโนไฟเบอร์ปริมาณ 2 ส่วนต่อยางร้อยส่วน แสดงสมบัติด้านความทนแรงดึงและความทนน้ำมันสูงกว่ายางธรรมชาติอิพอกซิไดส์ 1.80 และ 1.39 เท่า ตามลำดับ จากนั้นนำนาโนคอมพอสิตของยางธรรมชาติอิพอกซิไดส์/เซลลูโลสนาโนไฟ-เบอร์ไปเปรียบเทียบกับนาโนคอมพอสิตของยางธรรมชาติอิพอกซิไดส์/เซลลูโลสนาโนคริสตัลที่มีการไฮโดรไลซิสที่ความเข้มข้นของกรดต่าง ๆ ที่ปริมาณ 2 ส่วนต่อยางร้อยส่วน พบว่านาโนคอมพอสิตที่มีการใส่เซลลูโลสนาโนคริสตัลที่ไฮโดรไลซิสด้วยกรดความเข้มข้น 5 โมลาร์ มีสมบัติด้านความทนแรงดึงและความทนน้ำมันสูงที่สุด โดยมีค่าความทนแรงดึงและมอดุลัสที่ความเครียดร้อยละ 300 มีค่าเพิ่มขึ้น 1.89 และ 2 เท่า ตามลำดับ เมื่อเทียบกับยางธรรมชาติอิพอกซิไดส์ นอกจากนี้เมื่อทำการเปรียบเทียบกระบวนการผสมแบบเลเท็กซ์คอมพาวด์และ ‘อินซิทู’ พบว่ากระบวนการผสมแบบเลเท็กซ์คอมพาวด์มีสมบัติด้านความทนแรงดึงและความทนน้ำมันที่สูงกว่ากระบวนการผสมแบบ ‘อินซิทู’ เมื่อพิจารณาที่ปริมาณเซลลูโลนาโนคริสตัลในนาโนคอมพอสิตเท่า ๆ กัน
ตัวดูดซับคอปเปอร์(Ii) ไอออนที่เตรียมจากยางรถยนต์ใช้แล้ว, พิมลวัลย์ บุญโกย
ตัวดูดซับคอปเปอร์(Ii) ไอออนที่เตรียมจากยางรถยนต์ใช้แล้ว, พิมลวัลย์ บุญโกย
Chulalongkorn University Theses and Dissertations (Chula ETD)
งานวิจัยนี้มีวัตถุประสงค์เพื่อพัฒนาตัวดูดซับคอปเปอร์(II) ไอออน (Cu(II)) จากยางรถยนต์ใช้แล้ว (WTR) โดยการปรับปรุงผิว WTR ด้วยวิธีต่างกัน ได้แก่ การปรับปรุงผิวด้วยการเผา วิธีทางเคมี และแบบสองขั้นตอน โดยการปรับปรุงด้วยการเผาที่อุณหภูมิต่างกันคือ 320, 370 และ 400 องศาเซลเซียส การปรับปรุงผิวด้วยวิธีทางเคมีโดยการรีฟลักซ์ด้วยสารละลายกรดไนตริกที่เวลาต่างกันคือ 30, 60 และ 180 นาที และการปรับปรุงผิวแบบสองขั้นตอนคือการปรับปรุงผิวด้วยวิธีการเผาและวิธีทางเคมีร่วมกัน อีกทั้งงานวิจัยนี้ยังพัฒนาตัวดูดซับถ่านคาร์บอนซึ่งได้จากการเผาที่ 400 องศาเซลเซียส (h400-WTR) เป็นตัวดูดซับถ่านกัมมันต์ทั้งในรูปแบบผง (ac-WTR/powder) และแบบก้อน (ac-WTR/cube) โดยการกระตุ้นด้วยสารละลายกรดไนตริก ที่อุณหภูมิ 700 องศาเซลเซียส จากการทดลองพบว่าตัวดูดซับ h400-WTR มีความสามารถในการดูดซับมากที่สุดถึง 85% ซึ่งมากกว่าความสามารถในตัวดูดซับอื่น เป็นไปได้ว่ามีรูพรุนหรือพื้นที่ในการยึดเกาะกับ Cu(II) มากกว่าตัวดูดซับจากการปรับปรุงผิวด้วยวิธีทางเคมีและการปรับปรุงผิวแบบสองขั้นตอน โดยตัวดูดซับที่ปรับปรุงด้วยการเผาหรือด้วยวิธีทางเคมีนั้นไม่พบการปลดปล่อย Cu(II) ออกสู่น้ำกลั่นที่ทดสอบ ถ่านกัมมันต์แบบผงและแบบก้อนในงานวิจัยนี้มีพื้นที่ผิวจำเพาะต่ำกว่ามาตรฐานของถ่านกัมมันต์ แต่อย่างไรก็ตามตัวดูดซับถ่านกัมมันต์แบบผงที่เตรียมได้สามารถดูดซับ Cu(II) ไอออนสูงถึง 100% และมีค่าการดูดซับมากกว่าตัวดูดซับถ่านคาร์บอนทุกชนิด ทั้งนี้อาจเนื่องจากพื้นที่ผิวที่เพิ่มมากขึ้นจากการกระตุ้นด้วยกรดไนตริก โดยแบบก้อนดูดซับที่ 54% ซึ่งสามารถใช้งานในรูปแบบก้อนในน้ำได้โดยไม่แตกสลายใน 24 ชั่วโมง จึงน่าสนใจในการนำไปใช้งานกรณีที่การใช้งานไม่เหมาะกับแบบผง
Recently Developed Carbohydrate Based Gelators And Their Applications, Joedian Morris, Jonathan Bietsch, Kristen Bashaw, Guijun Wang
Recently Developed Carbohydrate Based Gelators And Their Applications, Joedian Morris, Jonathan Bietsch, Kristen Bashaw, Guijun Wang
Chemistry & Biochemistry Faculty Publications
Carbohydrate based low molecular weight gelators have been an intense subject of study over the past decade. The self-assembling systems built from natural products have high significance as biocompatible materials and renewable resources. The versatile structures available from naturally existing monosaccharides have enriched the molecular libraries that can be used for the construction of gelators. The bottom-up strategy in designing low molecular weight gelators (LMWGs) for a variety of applications has been adopted by many researchers. Rational design, along with some serendipitous discoveries, has resulted in multiple classes of molecular gelators. This review covers the literature from 2017-2020 on monosaccharide …
กาวที่ไวต่อแรงกดจากยูรีเทนอะคริเลตดัดแปรด้วยเอทิลเฮกซิลอะคริเลตและอะคริลิกแอซิด, ศุภศิลป์ ทัดสวน
กาวที่ไวต่อแรงกดจากยูรีเทนอะคริเลตดัดแปรด้วยเอทิลเฮกซิลอะคริเลตและอะคริลิกแอซิด, ศุภศิลป์ ทัดสวน
Chulalongkorn University Theses and Dissertations (Chula ETD)
งานวิจัยนี้มุ่งเน้นศึกษาสมบัติทางกายภาพ สมบัติการยึดติด และเสถียรภาพทางความร้อนของแผ่นเทปที่มีโครงสร้างแบบร่างแห (CL เทป) และแบบร่างแหกึ่งสอดไขว้ (SMI เทป) ที่พัฒนาจากอะคริลิกแอซิด (AA) เอทิลเฮกซิลอะคริเลต (EHA) ร่วมกับยูรีเทนอะคริเลต (UAO) ซึ่งสังเคราะห์จากพอลิเอทิลีนไกลคอล(PEG) ไอโซเฟอร์โรนไดไอโซไซยาเนต (IPDI) และไฮดรอกซีเอทิลอะคริเลต (HEA) ที่อัตราส่วนโมล 1:2:2 แผ่นเทป SMI พัฒนาจากอะคริเลตโคพอลิเมอร์ที่ต่างกัน 3 ชนิดคือ AC30 AC40 และ AC50 ซึ่งสังเคราะห์ด้วย AA/EHA ที่อัตราส่วนโดยโมล 30/70 40/60 และ 50:50 ตามลำดับ ผลการศึกษาพบว่า เทป SMI ที่พัฒนาจากสัดส่วนผสมของ UAO ต่อโคพอลิเมอร์ เป็น 20:80 และ 30:70 นั้น มีลักษณะขุ่น ไม่แข็งแรง เสียรูปหลังได้รับแรงกดเพียงเล็กน้อย ทิ้งคราบบนวัสดุพื้น แต่เมื่อปรับเพิ่มสัดส่วนเป็น 40:60 และ 50:50 แผ่นเทป SMI สูตรดังกล่าว มีแนวโน้มว่าสามารถประยุกต์ใช้เป็นเทปกาวชนิดไวต่อแรงกด ได้อย่างมีประสิทธิภาพมากขึ้น สำหรับแผ่นเทป CL ที่พัฒนาจากมอนอเมอร์ผสมของ AA/EHA (0:100, 10:90, 20:80, 30:70 โดยโมล) ร่วมกับ UAO (10%, 20% และ 30% โดยน้ำหนัก) นั้น มีลักษณะโปร่งแสง แข็งแรงและคงรูปได้ดี สามารถติดบนพื้นผิวได้ด้วยแรงกดเพียงเล็กน้อย และไม่ทิ้งคราบหลังลอกออก ทั้งนี้ค่าอุณหภูมิเปลี่ยนสถานะคล้ายแก้ว (Tg) และค่ามอดูลัสของแผ่นเทป CL มีแนวโน้มลดลงเมื่อลดสัดส่วนของ AA/EHA และลดปริมาณ UAO ลง ซึ่งสัมพันธ์กับสัดส่วนของส่วนแข็งและส่วนนุ่ม รวมถึงความยาวของสายโซ่ระหว่างจุดเชื่อมขวางนั่นเอง ทั้ง แผ่นเทป SMI และ CL มีเสถียรภาพทางความร้อนดีกว่าเทปที่พัฒนาจาก …
Advancements In Bio-Based Novel (Co)Monomers For Polymeric Materials, Khristal Anne Monroe
Advancements In Bio-Based Novel (Co)Monomers For Polymeric Materials, Khristal Anne Monroe
College of Graduate Studies: Theses & Dissertations
Most current research in the area of sustainable and environmentally friendly materials relate to the use of renewable sources for the fabrication of bio-based polymers and composites. Using plant-based derivatives is a common strategy. Pine sap can be distilled into turpentines (light fraction) and pine rosin (heavy fraction). Pine rosin is obtained as a brittle solid and its major component is abietic acid. This project aims at investigating a synthetic approach for the synthesis of a pine rosin-based polymer that can be potentially used for manufacturing a collection device for pine sap. The synthetic strategy consisted in the preparation of …
Multi-Level Analysis Of Atomic Layer Deposition Barrier Coatings On Additively Manufactured Plastics For High Vacuum Applications, Nupur Bihari
Dissertations, Master's Theses and Master's Reports
While hardware innovations in micro/nano electronics and photonics are heavily patented, the rise of the open-source movement has significantly shifted focus to the importance of obtaining low-cost, functional and easily modifiable research equipment. This thesis provides a foundation of open source development of equipment to aid in the micro/nano electronics and photonics fields.
First, the massive acceptance of the open source Arduino microcontroller has aided in the development of control systems with a wide variety of uses. Here it is used for the development of an open-source dual axis gimbal system. This system is used to characterize optoelectronic properties of …
Aggregation And Degradation Of Dispersants And Oil By Microbial Exopolymers (Addomex): Toward A Synthesis Of Processes And Pathways Of Marine Oil Snow Formation In Determining The Fate Of Hydrocarbons, Antonietta Quigg, Peter H. Santschi, Chen Xu, Kai Ziervogel, Manoj Kamalanathan, Wei-Chun Chin, Adrian B. Burd, Andrew Wozniak, Patrick G. Hatcher
Aggregation And Degradation Of Dispersants And Oil By Microbial Exopolymers (Addomex): Toward A Synthesis Of Processes And Pathways Of Marine Oil Snow Formation In Determining The Fate Of Hydrocarbons, Antonietta Quigg, Peter H. Santschi, Chen Xu, Kai Ziervogel, Manoj Kamalanathan, Wei-Chun Chin, Adrian B. Burd, Andrew Wozniak, Patrick G. Hatcher
Chemistry & Biochemistry Faculty Publications
Microbes (bacteria, phytoplankton) in the ocean are responsible for the copious production of exopolymeric substances (EPS) that include transparent exopolymeric particles. These materials act as a matrix to form marine snow. After the Deepwater Horizon oil spill, marine oil snow (MOS) formed in massive quantities and influenced the fate and transport of oil in the ocean. The processes and pathways of MOS formation require further elucidation to be better understood, in particular we need to better understand how dispersants affect aggregation and degradation of oil. Toward that end, recent work has characterized EPS as a function of microbial community and …
Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin
Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin
Master’s Theses
Polymer gels can be used in the fabrication of materials for filtering liquid and gaseous media, solid-state electrolytes, and transdermal medical patches. This diverse range of applications primarily relies on the transport and mechanical properties of polymer gels. Both sets of properties have shown excellent tunability, but typically in a coupled fashion. Establishing the independent tunability of the transport and mechanical properties of polymer gels (using simple, cost-effective methods) is paramount if polymer gels are to be used to their full potential. Specifically, block copolymer gels self-assemble into organized nanoscale networks within the gel solvent, which allows for facile control …