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Light-Driven Chemistry: Photoswitch In Rna Activity Control And Development Of Photoredox Catalysis, Juncheng Li Jan 2025

Light-Driven Chemistry: Photoswitch In Rna Activity Control And Development Of Photoredox Catalysis, Juncheng Li

Electronic Theses & Dissertations (2024 - present)

This dissertation is structured into two principal segments. The initial segment elucidates a series of synthetic works involving artificial molecules, specifically featuring the photosensitive azobenzene. These molecules facilitate remote control over the structure and functionality of biomolecules, with subsequent applications in regulating biological processes. The latter segment concentrates on the design and enhancement of organic photocatalysts, utilizing traditional acridine ions as a foundation. This section details the development of diverse organic photocatalyst-promoted processes, including photo Lewis acid catalysis, photo Brønsted acid catalysis, and photoredox reactions.


Synthesis Of Bio-Orthogonal Hydrogels For 3d Cell Culture Via Penicillamine Β-Thiolactone-Mediated Native Chemical Ligation, Kaelin E. Marshall, Matthew E. Currier, Nathan J. Oldenhuis Jan 2025

Synthesis Of Bio-Orthogonal Hydrogels For 3d Cell Culture Via Penicillamine Β-Thiolactone-Mediated Native Chemical Ligation, Kaelin E. Marshall, Matthew E. Currier, Nathan J. Oldenhuis

Honors Theses and Capstones

Many hydrogel systems designed to mimic the extracellular matrix (ECM) employ thiol-based chemistries with undesirable functional groups, including vinyl sulfones and methacrylates. In downstream applications, any unreacted functional groups are problematic and render hydrogels non-viable for human use. Here, we introduce modifications to the Native Chemical Ligation (NCL) mechanism, exploring the elimination of cytotoxic byproducts and increased reaction rate by using a β-thiolactone. The inclusion of the β-thiolactone results in retention of the thiol within the gel, as well as enhanced kinetics due to the thermodynamic favorability of the ring opening and amide formation. We achieved this by functionalizing 4-arm …


Extreme Value Theory Analysis Of High Emitter Trends Across Four Us Cities From 1995 To 2021, M. Matti Maricq, Gary A. Bishop Jan 2025

Extreme Value Theory Analysis Of High Emitter Trends Across Four Us Cities From 1995 To 2021, M. Matti Maricq, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

Extreme value theory provides a direct means to characterize the distribution of high emitters within a vehicle fleet and calculate statistical confidence intervals for comparisons. Defining a “high emitter” as the maximum emitter in a random sample of N vehicles implies in the limit of large N that high emitters follow an extreme value distribution, comprised of three distinct domains. The analysis of over twenty years of roadside remote sensing emissions measurements in Chicago, Denver, Los Angeles and Tulsa reveals clear differences between gasoline vehicle high emitter distributions across pollutants (hydrocarbons (HC), carbon monoxide (CO) and nitric oxide (NO)), but …


Functionalized 2d Hexaazatriphenylene As Hydrogen Storage Platform: A Dft-Guided Design Approach, Islam Gomaa Jan 2025

Functionalized 2d Hexaazatriphenylene As Hydrogen Storage Platform: A Dft-Guided Design Approach, Islam Gomaa

Nanotechnology Research Centre

No abstract provided.


Nontoxic High Temperature Resistant Hydrogels, Thomas P. Schuman, Baujun Bai, Buddhabhushan Pundlik Salunkhe Jan 2025

Nontoxic High Temperature Resistant Hydrogels, Thomas P. Schuman, Baujun Bai, Buddhabhushan Pundlik Salunkhe

Patents

Compositions of swellable non-toxic hydro gels and their use in conformance control are described herein. More specifically, the present invention generally relates to the hydro gels compositions that can be used to treat the oil reservoirs having high temperature and high salinity conditions. The compositions generally comprise a plurality of swellable particles having one or more crosslinkers interspersed within a polymer matrix. The compositions can also be used in biomedical, agricultural, fracking and similar applications wherein thermally-stable, nontoxic hydrogels are required.


Quantifying Inositol Phosphate Dephosphorylation To Understand The Role Of Recalcitrant Organic Phosphorus Forms On Harmful Algal Blooms In Freshwater Systems, Iffat Tasnim Jan 2025

Quantifying Inositol Phosphate Dephosphorylation To Understand The Role Of Recalcitrant Organic Phosphorus Forms On Harmful Algal Blooms In Freshwater Systems, Iffat Tasnim

College of Graduate Studies: Theses & Dissertations

Organophosphorus such as phytic acid, a surrogate species of inositol phosphate (IP), may serve as a source for orthophosphate (OP) in freshwater. In absence of OP, competent aquatic microorganisms upregulate the production of specialized enzymes to obtain growth-sustaining OP from organic phosphorus (org-P) forms. The contribution of recalcitrant org-P to the OP pool has been overlooked due to the lack of capable tools to measure OP production from org-P accurately. The objective of this study was to quantify OP production from phytic acid (a surrogate form of recalcitrant org-P) to assess the contribution of recalcitrant org-P forms to the total …


A New Paradigm For The Supramolecular Structure Of Laterally Offset Diarenes: Polymorphs Ii Of Para-Substituted Acetophenone Azines, Yp.Ph.(Me)C.N.N.C(Me).Ph.Yp (Y = Cl, Br, Ch3), Harmeet Bhoday, Kaidi Yang, Steven P. Kelley, Rainer Glaser Jan 2025

A New Paradigm For The Supramolecular Structure Of Laterally Offset Diarenes: Polymorphs Ii Of Para-Substituted Acetophenone Azines, Yp.Ph.(Me)C.N.N.C(Me).Ph.Yp (Y = Cl, Br, Ch3), Harmeet Bhoday, Kaidi Yang, Steven P. Kelley, Rainer Glaser

Chemistry Faculty Research & Creative Works

The crystal structures of polymorphs II of acetophenone azines YpPhRCNNCRPhYp with R = CH3 and Y = Cl (1M), Br (2M), and CH3 (8M) are discussed. The azine molecules in polymorphs II are Ci-symmetric with trans-azine moieties and conrotatory phenyl twists. Polymorphs 1M-I and 2M-I contain C2-symmetric enantiomers with pronounced azine twists and disrotatory phenyl twists and allow for strong lateral double T-contacts. The three polymorphs II exemplify the new Paradigm IV for the supramolecular architectures of "laterally offset diarenes" and result in "shiplap/flat" idioteloamphiphile monolayers. Intralayer lateral attraction is provided by edge-to-face arene-arene contacts …


Multiscale Computational Chemistry Studies Of The Catalytic Mechanisms Of Non-Heme Fe(Ii)/2-Oxoglutarate-Dependent Oxygenases, Simahudeen Bathir Jaber Sathik Rifayee Jan 2025

Multiscale Computational Chemistry Studies Of The Catalytic Mechanisms Of Non-Heme Fe(Ii)/2-Oxoglutarate-Dependent Oxygenases, Simahudeen Bathir Jaber Sathik Rifayee

Dissertations, Master's Theses and Master's Reports

Enzymes catalyze complex biological transformations. Non-heme Fe(II)/2-oxoglutarate (2OG)–dependent enzymes are highly versatile catalysts capable of selective C–H oxidation, enabling transformations such as hydroxylation, halogenation, desaturation, demethylation, ring rearrangements, epoxidation, and electrophilic aromatic substitution. These enzymes are involved in various biological processes, including fatty acid metabolism, hypoxic signaling, collagen maturation, and transcriptional regulation. Computational Modeling provides detailed knowledge of the enzymes including atomistic details of the important catalytic species, conformational and electronic effects, which are crucial to enzyme engineering and drug design efforts. This dissertation implements advanced multi-scale molecular modelling techniques including Molecular dynamics and Quantum Mechanic / Molecular Mechanics calculations …


New Psychoactive Substances Detected In Wastewater Samples Collected Along The Interstate Highway Rest Areas In Kentucky, Durga Prasad Kodati Jan 2025

New Psychoactive Substances Detected In Wastewater Samples Collected Along The Interstate Highway Rest Areas In Kentucky, Durga Prasad Kodati

Murray State Theses and Dissertations

The rapid emergence and proliferation of new psychoactive substances (NPS) pose significant challenges to public health and law enforcement. The potential for abuse and toxicity of these substances, which are intended to mimic the effects of controlled drugs, has been raising concerns as these compounds are designed to evade being regulated. There are traditional methods of tracking NPS, such as seizures and forensic toxicology, but they are delayed and seldom effective because these substances continue to evolve rapidly. Wastewater-based epidemiology (WBE) has emerged as a promising tool for real-time surveillance of drug consumption. The primary objective of this research was …


A Potentially Fruitful Path Toward A Cleaner And Safer Environment: Mxenes Uses In Environmental Remediation, Ali Mohammad Amani, Milad Abbasi, Atena Najdian, Farzaneh Mohamadpour, Seyed Reza Kasaee, Hesam Kamyab, Shreeshivadasan Chelliapan, Hanieh Ardeshiri, Lobat Tayebi, Ehsan Vafa, Sarah Mosleh-Shirazi, Alireza Jahanbin, Saravanan Rajendran, Daniel Simancas-Racines Jan 2025

A Potentially Fruitful Path Toward A Cleaner And Safer Environment: Mxenes Uses In Environmental Remediation, Ali Mohammad Amani, Milad Abbasi, Atena Najdian, Farzaneh Mohamadpour, Seyed Reza Kasaee, Hesam Kamyab, Shreeshivadasan Chelliapan, Hanieh Ardeshiri, Lobat Tayebi, Ehsan Vafa, Sarah Mosleh-Shirazi, Alireza Jahanbin, Saravanan Rajendran, Daniel Simancas-Racines

Electrical & Computer Engineering Faculty Publications

The rapid industrialization of the world has resulted in severe environmental pollution, necessitating the development of new materials such as pollution remediation. Two-dimensional (2D) MXenes have emerged as a promising family of materials due to their unique physicochemical properties, making them ideal for environmental remediation. The article sheds light on the new opportunities of MXenes in the removal of organic and inorganic contaminants, including organic dyes, pharmaceuticals, heavy metals, radionuclides, and gas pollutants. MXenes also show excellent performance in photocatalytic degradation, adsorption, and microbial inactivation with environmental safety. Moreover, their application in recovering valuable elements from waste streams is also …


The Development Of A One Pot, Two Reaction Synthetic Preparation Of 1,2,4-Oxadiazole, And Synthesis Of Ataluren, A Novel Drug In The Fight Against Duchenne Muscular Dystrophy. Efforts Towards The Synthesis Of A Potential Protease Inhibitor Against The Main Protease (3clpro) Of Covid-19, Austin J. Carter Jan 2025

The Development Of A One Pot, Two Reaction Synthetic Preparation Of 1,2,4-Oxadiazole, And Synthesis Of Ataluren, A Novel Drug In The Fight Against Duchenne Muscular Dystrophy. Efforts Towards The Synthesis Of A Potential Protease Inhibitor Against The Main Protease (3clpro) Of Covid-19, Austin J. Carter

Theses and Dissertations

1,2,4-Oxadiazoles are five-membered heterocyclic structures first synthesized by Tiemann and Krüger in 1884. Recent discoveries suggest an array of useful biological properties.In preparation of 1,2,4-oxadiazoles, the most prevalent precursors are amidoximes, which can be created via the reaction of nitriles with hydroxylamine hydrochloride and a base. The amidoximes are reacted with an activated carboxylic acid to yield an acylated intermediate. This intermediate can be exposed to a base to cyclize into the 1,2,4-oxadiazole. This thesis describes the efforts in combining these three steps into a unified one-pot synthesis.

Currently, there are a significant number of commercially available FDA approved and …


Asymmetric Synthesis Of The Hiv Protease Inhibitor Tmc-126 And An Anti-Malarial Agent Via A Titanium Tetrachloride Mediated Asymmetric Glycolate Aldol Addition Reaction. Redefining The Curtius Rearrangement Reaction Via Dehomologation Of Carboxylic Acids Bearing Alpha-Leaving Groups, Kweku Amaning Affram Jan 2025

Asymmetric Synthesis Of The Hiv Protease Inhibitor Tmc-126 And An Anti-Malarial Agent Via A Titanium Tetrachloride Mediated Asymmetric Glycolate Aldol Addition Reaction. Redefining The Curtius Rearrangement Reaction Via Dehomologation Of Carboxylic Acids Bearing Alpha-Leaving Groups, Kweku Amaning Affram

Theses and Dissertations

Acquired Immune Deficiency Syndrome (AIDS) and malaria are two devastating infectious diseases caused by HIV and Plasmodium parasites. AIDS is caused by HIV-1 and HIV-2, transmitted through sexual contact, blood transfusions, needle sharing, and perinatal routes. Malaria, caused by plasmodium parasites through mosquito bites. Today, millions of people around the world have been infected with HIV and malaria and much research has been done to treat it. However, despite advancements in therapeutic options, these diseases remain a significant global health threat, particularly in developing countries due to the emergence of drug-resistant strains for both HIV and malaria complicating eradication efforts. …


Site-Specific Modification Of Antibodies Utilizing Microbial Transglutaminase For Improved Immunoassay Performance, Emily Beitello Jan 2025

Site-Specific Modification Of Antibodies Utilizing Microbial Transglutaminase For Improved Immunoassay Performance, Emily Beitello

Theses and Dissertations

Immobilization strategies used for fixing antibodies to solid phase surfaces significantly contribute to the antigen capture capacity and influences the performance and sensitivity of immunoassays. Traditional methodologies result in the random orientation and/or the weak attachment of immobilized antibodies. Different formats of immunoassays scope in applicability to many fields of research and everyday use. Improving the efficiency of immobilizing antibodies in immunoassays is a beneficial endeavor to increase assay sensitivity. Here, we investigated the use of enzyme-mediated conjugation of antibodies to facilitate a highly oriented immobilization. Microbial transglutaminase (mTG) catalyzes the covalent bond formation between a plethora of primary amine …


Scalable Fabrication Of High-Payload Dendrimer-Based Nanoparticles For Targeted Atherosclerosis Therapy, Huari Kou, Lin Qi, Da Huang, Jiandong Wu, Honglan Shi, Hu Yang Jan 2025

Scalable Fabrication Of High-Payload Dendrimer-Based Nanoparticles For Targeted Atherosclerosis Therapy, Huari Kou, Lin Qi, Da Huang, Jiandong Wu, Honglan Shi, Hu Yang

Chemistry Faculty Research & Creative Works

Nanoparticle-based therapeutics hold promise for the treatment of atherosclerosis, but challenges such as low drug-loading capacity and a lack of scalable, controllable production hinder their clinical translation. Flash nanoprecipitation, a continuous synthesis method, offers a potential solution for scalable and reproducible nanoparticle production. In this study, we employed a custom-designed multi-inlet vortex mixer to perform cross-linking reaction-enabled flash nanoprecipitation, facilitating controlled and scalable synthesis of cross-linked Poly amidoamine (PAMAM) dendrimer nanoparticles. Notably, this approach allows simultaneous nanoparticle cross-linking and drug loading in a single step. The mannose moiety enabled specific targeting of macrophages via mannose receptors, enhancing the localization of …


Enhanced Biofuel Cells Based On A Hybrid Enzymatic/Bimetallic Composite For Complete Lactate Catalytic Electrooxidation, Jefferson Honorio Franco, João Victor Bonaldo, Shelley D. Minteer, Adalgisa R. De Andrade Jan 2025

Enhanced Biofuel Cells Based On A Hybrid Enzymatic/Bimetallic Composite For Complete Lactate Catalytic Electrooxidation, Jefferson Honorio Franco, João Victor Bonaldo, Shelley D. Minteer, Adalgisa R. De Andrade

Chemistry Faculty Research & Creative Works

We describe complete lactate electrooxidation in an enzymatic biofuel cell that combines the catalytic action of the bimetallic composite Ru@Pt-CNT and the enzyme oxalate oxidase (OxOx). The Ru@Pt-CNT/OxOx hybrid electrode was 2.0-fold more catalytically active than the electrode containing the bimetallic composite only. During chronoamperometric experiments, the hybrid electrode achieved a 35% higher maximum current density (2.65 ± 0.15 mA cm-2) than the Ru@Pt-CNT electrode. Electrochemical impedance spectroscopy showed that the hybrid electrode had lower charge transfer resistance than the Ru@Pt-CNT electrode, confirming that OxOx had a high affinity for lactate during the bioelectrocatalytic reaction on the electrode …


Metal-Free Photoredox Catalysis For The S-Trifluoromethylation Of Thiols And Investigation Of Ph-Dependent Decontamination Of Dimethyl Chlorophosphate, A Nerve Agent Simulant, Via Hydrolysis With Azoles, Raheemat Rafiu Jan 2025

Metal-Free Photoredox Catalysis For The S-Trifluoromethylation Of Thiols And Investigation Of Ph-Dependent Decontamination Of Dimethyl Chlorophosphate, A Nerve Agent Simulant, Via Hydrolysis With Azoles, Raheemat Rafiu

Doctoral Dissertations

"Organofluorine chemistry plays a critical role in synthetic chemistry due to the unique properties of fluorine. However, the S-trifluoromethylation of thiols remains underexplored, with existing methods often relying on toxic and expensive organometallic catalysts. Given the advantages of S-trifluoromethylated compounds, including enhanced pharmacological activity and improved metabolic stability, we developed a green and cost-effective method for the synthesis of S-CF3 compounds using diacetyl as the organic catalyst and Langloi's reagent as the trifluoromethylating reagent. This reaction, which proceeds under mild conditions using visible light photoredox catalysis, works across various substrate scopes, including aromatic, heteroaromatic, and aliphatic thiols.

Chemical Warfare Agents …


Design And Synthesis Of Organocatalyts For Efficient Decontamination Of Organophosphate-Based Nerve Agents And Pesticides, Emmanuel Kingsley Darkwah Jan 2025

Design And Synthesis Of Organocatalyts For Efficient Decontamination Of Organophosphate-Based Nerve Agents And Pesticides, Emmanuel Kingsley Darkwah

Doctoral Dissertations

Exposure to organophosphate-based nerve agents and pesticides poses significant health and security threats to civilians, soldiers, and first responders. Despite extensive efforts to develop chemical detoxification agents for use in topical applications on exposed skin surfaces and for intravenous injections, there remains an unmet need for effective, non-hazardous decontaminating agents. The current state-of-the-art decontaminating agent, Dekon-139 (2,3-butanedione oxime, potassium salt), exhibits adverse effects when applied to the skin.

In this study, we designed and synthesized pharmaceutically relevant aminoguanidine-derived aldimines that are relatively non-toxic and substantially more effective at decontaminating nerve agents and pesticides compared to existing agents, and they act …


Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones Jan 2025

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …


Structural Optimization And Stability Enhancement Of Uba(2) And Ntl9 Using The Computational Tool: Emcast, Bahar Ghazi Esfahani Jan 2025

Structural Optimization And Stability Enhancement Of Uba(2) And Ntl9 Using The Computational Tool: Emcast, Bahar Ghazi Esfahani

Graduate Student Theses, Dissertations, & Professional Papers

This study enhances protein stability prediction by refining EmCAST (Empirical C-Alpha Stability Tool), a computational tool used to identify stabilizing mutations in protein domains. We applied EmCAST to two model proteins: the α-helical ubiquitin-associated domain 2 (UBA(2)) and the α/β N-terminal domain of ribosomal protein L9 (NTL9). Protein stability is critical for proper function, and mutations can lead to misfolding and disease. To validate EmCAST’s predictions, guanidine hydrochloride-induced denaturation was monitored using circular dichroism (CD) spectroscopy for both wild-type and mutant variants. Results guided refinements to EmCAST’s algorithm, incorporating new experimental datasets to improve accuracy. Additionally, we examined the assumption …


Effect Of Single Screw Extrusion Process Parameters On Gel Formation And Properties In Polycaprolactone Films, Kitthanya Ritthichai Jan 2025

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 …


Functional Design Of Dissymmetric Ligands For Coordination Systems, Kaitlyn R. Brown Jan 2025

Functional Design Of Dissymmetric Ligands For Coordination Systems, Kaitlyn R. Brown

Theses and Dissertations (Comprehensive)

Herein, the functional design of dissymmetric ligands for coordination systems is explored with a focus on their synthesis and structural characterization. The design strategy of these ligands incorporates the ability to coordinate both metal cations and anions along with a ligand site for other functionalization. Their synthesis, structural and other characterization, Hirshfeld surface analysis, and some metal-coordinated complexes are discussed. Chapter 1 introduces supramolecular and coordination chemistry, along with relevant literature that supports this research and outlines the thesis objective. Chapter 2 investigates the hydrogen bonding of a dissymmetric pyrimidine thioether ligand in its neutral form, water solvate, protonated nitrate …


Development Of Cyan And Blue Thermostable Fluorescent Proteins: Characterization And Structural Analysis, Acacia J. Jurkowski Jan 2025

Development Of Cyan And Blue Thermostable Fluorescent Proteins: Characterization And Structural Analysis, Acacia J. Jurkowski

Graduate Theses/Dissertations

Fluorescent proteins are commonly used as cell markers in living organisms. Modifications by mutation can be used to improve the qualities of these proteins including fluorescence, thermostability, pH stability, and chemical stability. The goal of this project is to use mutagenesis to improve the fluorescence of thermostable cyan and blue proteins derived from the thermal green protein (TGP). The first cyan protein developed by the DeVore lab (CTP 0.0) shifted the fluorescence to cyan but decreased the quantum yield (ΦF) to 0.056. Further mutations were incorporated to increase the quantum yield through incorporating hydrogen bonding interactions to the …


Production Of Graphene From Graphite Via Flash Joule Heating Process, Siranut Sirathanutworakan Jan 2025

Production Of Graphene From Graphite Via Flash Joule Heating Process, Siranut Sirathanutworakan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Graphene is a material with unique properties and high potential. Due to its outstanding characteristics in strength, electrical and thermal conductivity, and flexibility, graphene is considered one of the materials of the future that can be used to enhance the efficiency of various emerging technologies. This research focuses on the synthesis of graphene using the Flash Joule Heating (FJH) process, during which an extremely high temperature occurs within milliseconds. The carbon precursor is rapidly exposed to intense heat, resulting in the dissociation of all chemical bonds in its structure and the reorganization of carbon atoms into a new graphene structure. …


การสังเคราะห์แกรฟีนควอนตัมดอตฐานกรดฮิวมิกและการประยุกต์เป็นสารเคลือบเซนเซอร์ตรวจจับความเครียด, ปริตตา จูฑาภักติ Jan 2025

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 Jan 2025

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


Long Oligos: Direct Chemical Synthesis Of Genes With Up To 1728 Nucleotides, Yipeng Yin, Reed Arneson, Yinan Yuan, Shiyue Fang Jan 2025

Long Oligos: Direct Chemical Synthesis Of Genes With Up To 1728 Nucleotides, Yipeng Yin, Reed Arneson, Yinan Yuan, Shiyue Fang

Michigan Tech Publications

The longest oligos that can be chemically synthesized are considered to be 200-mers. Here, we report direct synthesis of an 800-mer green fluorescent protein gene and a 1728-mer Φ29 DNA polymerase gene on an automated synthesizer. Key innovations that enabled this breakthrough include conducting the synthesis on a smooth surface rather than within the pores of traditional supports, and the use of the powerful catching-by-polymerization (CBP) method for isolating the full-length oligos from a complex mixture. Conducting synthesis on a smooth surface not only eliminated the steric hindrance that would otherwise prevent long oligo assembly, but also, surprisingly, drastically reduced …


First-Principles Study Of Ferroelectric Properties And Co2 Reduction Reaction Capabilities In Two-Dimensional Monolayers And Heterostructures, Mo Li Dec 2024

First-Principles Study Of Ferroelectric Properties And Co2 Reduction Reaction Capabilities In Two-Dimensional Monolayers And Heterostructures, Mo Li

Dissertations

Two-dimensional (2D) materials hold significant potential for CO2 reduction reactions (CO2RR) due to their high surface-to-volume ratio. However, achieving high selectivity for desired products and overcoming limitations posed by scaling relationships remain challenging. Recent studies suggest that ferroelectric (FE) materials with switchable out-of-plane polarization (OOP) can effectively tune the adsorption behavior, thermodynamics, and kinetics of CO2RR, offering promising solutions to these challenges. Using density functional theory (DFT) and the Berry phase approach, this work expands the family of 2D ferroelectrics by theoretically identifying Y2CO2, Y2CS2, and Sc …


Single-Step Synthesis Of Activated Carbon From Arabica Spent Coffee Ground Using K2co3 As Activator Agent, Ghina Ivana Mieldan, Yuliusman Yuliusman Dec 2024

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 Dec 2024

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 …


Composite Volume Learning Media Based On Augmented Reality To Enhance Students’ Visual-Spatial Intelligence, Ria Kurniawati, Susiswo Susiswo, Syamsul Hadi Dec 2024

Composite Volume Learning Media Based On Augmented Reality To Enhance Students’ Visual-Spatial Intelligence, Ria Kurniawati, Susiswo Susiswo, Syamsul Hadi

Jurnal Pendidikan Sains

Augmented Reality (AR) technology, a three-dimensional visual tool that integrates virtual objects or environments into real-world displays in real time (Azuma et al., 2001), is particularly useful for grasping complex concepts such as the composite volume of solids, which often confuses students when they need to decompose solids into their individual components. While previous research has predominantly focused on the introduction of solids, spatial nets, and the volume of singular shapes, this study aims to develop composite volume learning media based on AR to enhance students’ visual-spatial intelligence in a valid, practical, and effective manner, aligning with their concrete operational …