Synergistic Reinforcement Of Lignin–Chitosan Hydrogels Using Vanillin As A Sustainable Green Crosslinker, Moses Ayitey-Adjin Jr., Mohammad Jahid Hasan, Jeremy Erb, Kishore Chand, Garry S. Crosson, Kenya Crosson, Esteban Ureña-Benavides, Erick Salvador Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

While bio-based hydrogels derived from lignin and chitosan are promising sustainable adsorbents, their practical application is hindered by poor mechanical stability. This study addresses this limitation by synthesizing lignin-chitosan hydrogels using vanillin as a green, bio-derived crosslinker via a facile solution-casting method. The formation of imine (Schiff base) linkages between the aldehyde groups of vanillin and the primary amines of chitosan was confirmed by FTIR spectroscopy (C = N stretching at ~ 1602 cm^− 1). SEM and TGA results demonstrated a reduction in the pore size of the crosslinked hydrogel and an enhanced residual thermal mass. Rheological and …

Magnetic Cellulose Nanocrystal Composites: Synthesis, Properties, Applications, And Opportunities, Mohammad Jahid Hasan, Kishore Chand, Esteban E. Ureña-Benavides, Erick S. Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

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Magnetic Cellulose Nanocrystal Composites: Synthesis, Properties, Applications, and Opportunities

Metal Oxide Nanoparticle‑Integrated Phema Hydrogels: Morphology, Chemical Properties, And Biological Interaction, Venkateswar Rao, Collin Cox, Brandon Clark, Arushi Rai, Erick S. Vasquez-Guardado, Madhuri Kango-Singh, Soubantika Palchoudhury

Chemical and Materials Engineering Faculty Publications

Hydrogels offer attractive matrices for incorporating inorganic metal oxide nanoparticles (NPs) to generate multifunctional hybrid materials, but challenges remain in scalable synthesis and correlating their properties to bio-interaction. Therefore, we report the synthesis and characterization of poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogels, and pHEMA hydrogels encapsulating iron oxide or zinc oxide NPs, using a modified free-radical polymerization. Dose-dependent survivorship studies on Drosophila melanogaster revealed that both NP-embedded hydrogels are tolerated over a wide dose range (e.g., 50–200 mg), although ZnO NP-gels exhibit lower survivorship at some concentrations due to their inherent composition and a wider size distribution of iron oxide NPs.

Polymer-Derived Silicon Oxycarbide (Sioc) And Silicon Carbonitride (Sicn) Ceramics For Advanced Electrochemical Energy Storage Applications, Saja Al Ajrash, Erick S. Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

Preceramic polymers, especially silicon oxycarbide (SiOC) and silicon carbonitride (SiCN) ceramics, have gained significant attention due to their wide range of applications in many fields, particularly in energy storage devices beyond conventional lithium-ion batteries (LIBs). This review focuses on the synthesis, structural characteristics, and properties of SiOC and SiCN ceramics as electrodes for battery applications. Furthermore, their promising applications as electrode materials for energy storage systems are explored, along with the most recent advances in the development of such materials and their use in lithium-ion batteries (LIBs), lithium-sulfur batteries (LSBs), potassium-ion batteries (PIBs), sodium-ion batteries (SIBs), and supercapacitors. This review …

Self-Assembly Interactions In Magnetite-Coated Cellulose Nanocrystals: Implications For Magnetic Hyperthermia Applications, Mohammad J. Hasan, Erin L. Mcneill, Kishore Chand, Juganta Roy, Monishita Deb, Katherine Schlaak, Sydney Herzog, Yvonne Sun, Sarah Watzman, Esteban E. Ureña-Benavides, Erick S. Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

Magnetic cellulose nanocrystal (MCNC) nanocomposites are promising sustainable and biocompatible platforms for magnetic hyperthermia; however, the molecular mechanisms governing Fe3O4 adsorption and deposition onto CNCs remain poorly understood. Here, sulfated (S-CNC) and TEMPO-oxidized CNCs (T-CNC) were used to prepare nanocomposites at 1:2 and 1:4 CNC:Fe3O4 mass ratios, enabling a systematic evaluation of how surface chemistry and nanoparticle loading dictate interfacial interactions and magneto-colloidal behavior. Bare magnetite nanoparticles were 21 ± 5 nm by TEM but grew to 144 ± 18 in the DLS measurement at pH 7. The S-CNC nanocomposites had hydrodynamic sizes between 144 and 210 nm, not much …

Synthesis And Characterization Of Temperature- And Ph-Responsive Pia-B-Pnipam@Fe3O4 Nanocomposites, Swati Kumari, Cayla Cook, Fatema Tarannum, Erick Salvador Vasquez-Guardado, Olufemi Ogunjimi, Keisha B. Walters

Chemical and Materials Engineering Faculty Publications

Stimuli-responsive polymers (SRPs) have garnered significant attention in recent decades due to their immense potential in biomedical and environmental applications. When these SRPs are grafted onto magnetic nanoparticles, they form multifunctional nanocomposites capable of various complex applications, such as targeted drug delivery, advanced separations, and magnetic resonance imaging. In this study, we employed a one-step hydrothermal method using 3-aminopropyltrimethoxysilane (APTES) to synthesize APTES-modified Fe₃O₄ nanoparticles (APTES@Fe₃O₄) featuring reactive terminal amine groups. Subsequently, via two consecutive surface-initiated atom transfer radical polymerizations (SI-ATRP), pH- and temperature-responsive polymer blocks were grown from the Fe₃O …

Magnetic Nanoparticles: Synthesis And Applications In Life Sciences, Kishore Chand, Erick Salvador Vasquez

Chemical and Materials Engineering Faculty Publications

Magnetic nanoparticles (MNPs) are multifunctional materials with superparamagnetic properties and tunable surface chemistries, making them valuable across diverse fields, such as biomedicine, environmental remediation, and agriculture. This review examines recent advancements in MNP synthesis, encompassing chemical, physical, and environmentally friendly methods while highlighting improvements in size, morphology, and composition control that enhance application-specific performance and environmental sustainability. The review discusses various architectures, including single-core, core–shell, hybrid composites, and stimuli–responsive systems, with an emphasis on their stability, scalability, and functionalization potential. In biomedical applications, MNPs show promise in targeted drug delivery, magnetic hyperthermia, and magnetic resonance imaging contrast enhancement, where biocompatibility, …

Work In Progress: Exploring The Impact Of International Experiences On The Development Of Students’ Entrepreneurial Mindset, Olgha Bassam Qaqish, Marcia Pool, William H. Pennock, Erick Salvador Vasquez, Fahmidah Ummul Ashraf

Chemical and Materials Engineering Faculty Publications

International experiences, including collaborative online international learning (COIL) experiences that naturally increase accessibility, are of interest to many undergraduate students. These experiences provide educators a unique opportunity to develop a student's entrepreneurial mindset (EM). Additionally, hands-on experiences aligned with the National Academy of Engineering’s (NAE) grand challenge themes (Sustainability, Security, Health, and Joy of Living) support connections between the experience, disciplinary knowledge, multicultural awareness, and EM. Through this Work-in-Progress (WiP) study, we seek to answer: 1) How do international experiences influence undergraduate science and engineering students’ EM, and 2) How does the international experience modality (i.e., study abroad or COIL) …

Camino—Career Advancement, Mentorship, Inspiration, And Opportunities: A Stem K-12 Outreach Initiative, Hector A. Pulgar, Francisco Zelaya-Arrazabal, Erick Salvador Vasquez, Sebastian N. Martinez Lizana

Chemical and Materials Engineering Faculty Publications

CAMINO is a STEM program designed to promote career advancement, provide mentorship, give inspiration, and offer opportunities for K-12 Hispanic students located in East Tennessee. As part of the educational component of an NSF CAREER grant, the program launched in 2021 and is a collaboration between a research group from the University of Tennessee and one of the high schools with the largest Hispanic populations in the Knoxville Metropolitan area. These students from minority backgrounds may limit their aspirations and may not pursue higher education and/or professional development for numerous reasons, such as limited motivation, insufficient exposure to higher education, …

Entrepreneurially Minded Learning (Eml) Micromoment Activities Generated Using Students' Experiences In A Fluid Flow And Heat Transfer Course, Erick Salvador Vasquez, Megan Morin

Chemical and Materials Engineering Faculty Publications

The Entrepreneurially Minded Learning (EML) Framework involves the 3 C's: curiosity, connections, and creating value. Several design courses, open-ended assignments, and laboratory experiences can successfully lead to EML implementations. However, these implementations require extensive class time and instructor feedback, limiting their use in core engineering courses. Developing EML activities that are active, engaging, and rapid to deploy in a classroom setting can promote the sustained growth of an entrepreneurial mindset (EM). EML micromoment activities are emerging as a practical tool to facilitate the incorporation of the 3 Cs through rapid activity implementations that only last 2 – 30 minutes. These …

Student-Led Video Podcasting In A Chemical Behavior Of Materials Course, Erick Salvador Vasquez

Chemical and Materials Engineering Faculty Publications

Video podcasts, or vodcasts, are a form of podcasting that combines video and audio to deliver various types of educational content effectively. To our knowledge, very few studies have focused on student-produced podcasting for learning technical engineering concepts. This study explores using student-created technical videos in a course on the chemical behavior of materials through three separate assignments. The first assignment centered on sustainability aspects. Students, divided into groups of three, were tasked to review two influential journal articles on plastic waste input into the ocean and metal recycling. Each group had to prepare and deliver a technical script about …

A High-Temperature Lithium-Aluminum Alloy/Oxygen Or Air Fuel Cell, Sarwan S. Sandhu

Chemical and Materials Engineering Faculty Publications

This paper is in support of our current effort in the development of an experimental hybrid (lithium- aluminum alloy/electrolyte/oxygen or air) fuel cell for the acquisition of the experimental data required to characterize its performance behavior. The literature-based assembled formulation provided in this paper can be used to predict the cell open-circuit electric potential, lithium amount in the cell anode alloy, and g-atom ratio of lithium to aluminum in the cell anode as a function of time at any cell discharge current level. The ohmic voltage losses can also be computed in the cell cathode, anode, and two electrolytes at …

Assessing Global Engagement Interventions To Advance Global Engineering Competence For Engineering Formation, Scott Schneider, Erick S. Vasquez-Guardado, Corinne Mowrey, Michael Moulton, Homero Murzi, Matthew A. Witenstein

Chemical and Materials Engineering Faculty Publications

This paper summarizes the work performed during the first year of a collaborative Research Initiation in Engineering Formation (RIEF) project focused on assessing the formation of a global learner mindset in engineering students through the use of different types of global engagement interventions without extended international travel. During this year the global engagement interventions have been developed, piloted, and assessed using the Global Engagement Survey (GES) and Global Engineering Competency Scale (GECS) instruments in a pre and post format. The assessment results helped the research team update the interventions and refine the assessment strategy, including the addition of new qualitative …

Work In Progress: Exploring The Impact Of International Experiences On The Development Of Students’ Entrepreneurial Mindset, Olgha Bassam Qaqish, Marcia Poole, William Pennock, Erick S. Vasquez-Guardado, Fahmidah Ummul Ashraf

Chemical and Materials Engineering Faculty Publications

International experiences, including collaborative online international learning (COIL) experiences that naturally increase accessibility, are of interest to many undergraduate students. These experiences provide educators a unique opportunity to develop a student's entrepreneurial mindset (EM). Additionally, hands-on experiences aligned with the National Academy of Engineering’s (NAE) grand challenge themes (Sustainability, Security, Health, and Joy of Living) support connections between the experience, disciplinary knowledge, multicultural awareness, and EM. Through this Work-in-Progress (WiP) study, we seek to answer: 1) How do international experiences influence undergraduate science and engineering students’ EM, and 2) How does the international experience modality (i.e., study abroad or COIL) …

Enhancing Entrepreneurial Minded Learning Of Process Control And Heat Transfer Concepts Using Micromoments And Concept Maps, Erick S. Vasquez-Guardado, Ricardo Gomez Gonzalez, Jean M. Andino, Nilza D. Aples, Xiaojing Yuan

Chemical and Materials Engineering Faculty Publications

The Entrepreneurially Minded Learning (EML) Framework seeks to infuse an Entrepreneurial Mindset in engineering students. The EML framework is founded on the 3 C’s principles of curiosity, connections, and creating value. Assessing EML efforts, however, is a well-known challenge for many engineering courses that do not have a design component. Through concept maps and micromoment activities, this work seeks to answer the following questions: Does implementing micromoment activities enhance students’ EML in two core areas of chemical engineering, i.e., heat transfer and process controls? A secondary research question is whether introducing a physical device in lectures enhances students’ EML. The …

Using Micromoments And Concept Maps To Enhance Entrepreneurially Minded Learning Of Indoor Air Pollution Control, Jean M. Andino, Erick Salvador Vasquez-Guardado, Ricardo Gomez Gonzalez, Xiaojing Yuan, Nilza D. Aples

Chemical and Materials Engineering Faculty Publications

Micromoments targeted toward indoor air quality were introduced to students in an Air Quality Engineering course to enhance their entrepreneurial mindset. Three micromoment activities, i.e., “Question Frenzy”, “Make It Relevant”, and “How Do We Make It Better?” that are linked, respectively, to the curiosity, connections, and creating value elements of EM were deployed in the class in the context of the use of a Corsi Rosenthal cube (a do-it-yourself structure that has recently become popular as an inexpensive way to reduce indoor particle pollution). Students generated concept maps pre-and post- micromoment intervention using the freely available CMap Tools software. The …

Experimental Thermal Conductivity Studies Of Agar-Based Aqueous Suspensions With Lignin Magnetic Nanocomposites, Bishal Gautam, Saja M. Nabat Al-Ajrash, Mohammad Jahid Hasan, Abhishek Saini, Sarah J. Watzman, Esteban Ureña-Benavides, Erick S. Vasquez-Guardado

Chemical and Materials Engineering Faculty Publications

Nanoparticle additives increase the thermal conductivity of conventional heat transfer fluids at low concentrations, which leads to improved heat transfer fluids and processes. This study investigates lignin-coated magnetic nanocomposites (lignin@Fe₃O₄) as a novel bio-based magnetic nanoparticle additive to enhance the thermal conductivity of aqueous-based fluids. Kraft lignin was used to encapsulate the Fe₃O₄ nanoparticles to prevent agglomeration and oxidation of the magnetic nanoparticles. Lignin@Fe₃O₄ nanoparticles were prepared using a pH-driven co-precipitation method with a 3:1 lignin to magnetite ratio and characterized by X-ray diffraction, FT-IR, thermogravimetric analysis, and transmission electron …

Novel Castor Oil/Water/Ethanol Pickering Emulsions Stabilized By Magnetic Nanoparticles And Magnetically Controllable Demulsification, Mohammad J. Hasan, Peng Chen, Neithan Dominick, Erick S. Vasquez, Esteban E. Ureña-Benavides

Chemical and Materials Engineering Faculty Publications

A novel castor oil/water/ethanol Pickering emulsion, stabilized by magnetic nanoparticles (NPs), was developed to allow on-demand demulsification by an external magnetic field for the extraction of ethanol from aqueous solution using the castor oil. The emulsion was stabilized by Fe3O4-coated cellulose nanocrystals (CNC@Fe3O4) and lignin-coated Fe3O4 NPs (lignin@Fe3O4). The stability of the emulsions was investigated at various castor oil to ethanol-water ratios (50/50 and 70/30), various NP concentrations, and ethanol concentrations in the aqueous phase. The magnetically controlled demulsification ability of the emulsions was investigated by using a permanent magnet. The results showed that the 70/30 emulsions were more stable …

Adsorptive Properties And On-Demand Magnetic Response Of Lignin@Fe3o4 Nanoparticles At Castor Oil–Water Interfaces, Mohammad J. Hasan, Emily Westphal, Peng Chen, Abishek Saini, I-Wei Chu, Sarah J. Watzman, Esteban E. Ureña-Benavides, Erick S. Vasquez

Chemical and Materials Engineering Faculty Publications

Lignin@Fe3O4 nanoparticles adsorb at oil–water interfaces, form Pickering emulsions, induce on-demand magnetic responses to break emulsions, and can sequester oil from water. Lignin@Fe3O4 nanoparticles were prepared using a pH-induced precipitation method and were fully characterized. These were used to prepare Pickering emulsions with castor oil/Sudan red G dye and water at various oil/water volume ratios and nanoparticle concentrations. The stability and demulsification of the emulsions under different magnetic fields generated with permanent magnets (0–540 mT) were investigated using microscopy images and by visual inspection over time. The results showed that the Pickering emulsions were more stable at the castor oil/water …

Liquid-Liquid Equilibria Of Water + Ethanol + Castor Oil And The Effect Of Cellulose Nanocrystal/Fe3o4 And Lignin/Fe3o4 Nanoparticles, Mohammad J. Hasan, Fariba Yehaneh, Amy Ciric, Peng Chen, Erick S. Vasquez, Esteban E. Ureña-Benavides

Chemical and Materials Engineering Faculty Publications

Castor oil has been proposed as a renewable solvent for the liquid extraction of ethanol from water as an alternative to more traditional energy intensive distillation-based methods. The liquid–liquid equilibrium (LLE) of the ternary system water + ethanol + castor oil was determined at 295.15 K using high performance liquid chromatography (HPLC). Castor oil was herein treated as a pseudo-component with the molecular weight of the triglyceride of ricinoleic acid. The experimental data was fitted to the UNIQUAC and NRTL models to obtain parameters for castor oil, and binary interaction parameters for castor oil/ethanol and castor oil/water pairs. The separation …

Preparation, Cure, And Characterization Of Cyanate Ester-Epoxy Blends Containing Reactive Flame Retardants, Mustafa Mukhtar, Donald A. Klosterman

Chemical and Materials Engineering Faculty Publications

Cyanate ester resins are sometimes mixed with lower cost epoxy monomers to modify cost, toughness, and processing capabilities. Despite the high performance of these thermosetting polymers, flame retardancy remains an issue. This study examined blends of three different commercial cyanate ester monomers (LVT-100, LECy, and XU-71787.02) and diglycidyl ether of bisphenol A (DGEBA) at 50/50 wt% of each type. The blends were successfully reacted with two reactive flame retardants (FR): 9,10-dihydro-9-ox-9-phosphaphenanthrene-10-oxide (DOPO) and poly(m-phenylene methylphosphonate) (PMP) at phosphorus contents ranging from 0 to 3 wt%. The curing behavior of EP/CE blends was investigated using differential scanning calorimetry (DSC). It was …

Synthesis Of A Phosphorus-Based Epoxy Reactive Flame Retardant Analog To Diglycidyl Ether Of Bisphenol A (Dgeba) And Its Behavior As A Matrix In A Carbon Fiber Composite, Mustafa Mukhtar

Chemical and Materials Engineering Faculty Publications

This paper describes the synthesis of a phosphorus-based flame retardant that is a chemical analog of diglycidyl ether of bisphenol A (DGEBA), as well as its incorporation as a matrix into carbon fiber laminates. Carbon fiber composites, if used for structural applications in mass transport vehicles (aircraft, trains), will require some aspects of improved fire performance to be used safely in those applications. The first phase of work involved the development of two separate synthesis routes to produce the flame retardant monomer, referred to as Phosphorus-DGEBA or simply P-DGEBA. The second step was to determine the viability of the compound's …

Identification Of Lithocholic Acid As A Molecular Glass Host For Room-Temperature Phosphorescent Materials, John J. Flynn, Zachary M. Marsh, Douglas M. Krein, Steven M. Wolf, Joy E. Haley, Erick S. Vasquez, Thomas M. Cooper, Nicholas P. Godman, Tod A. Grusenmeyer

Chemical and Materials Engineering Faculty Publications

Lithocholic acid was identified as a molecular glass host material for room temperature phosphorescent (RTP) chromophores. Differential scanning calorimetry (DSC) was performed on a series of structurally similar, biologically sourced molecules, including lithocholic acid, β-estradiol, cholesterol, and β-sitosterol, in an effort to identify new amorphous molecular glasses independent of plasticizing additives. DSC analysis revealed lithocholic acid and β-estradiol form stable molecular glasses post thermal processing unlike neat cholesterol and β-sitosterol. The ability of lithocholic acid and β-estradiol to stabilize high wt. % loadings of d10-pyrene and a mixture of d10-pyrene and an iridium chromophore, bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate iridium(III) (FIr6), was also investigated. …

Preparation, Cure, And Characterization Of Cyanate Ester-Epoxy Blends, Donald A. Klosterman

Chemical and Materials Engineering Faculty Publications

Cyanate ester resins are often blended with lower cost epoxy monomers in order to modify the cost, toughness, and processing characteristics. There are also several choices of catalysts that can be used to improve processing, namely by reducing the cure temperature. This study was undertaken to illustrate how a designed experiment approach can be used to systematically investigate a wide range of material combinations and illuminate the basic cure behavior of some simple cyanate ester – epoxy blend combinations. Two commercial cyanate ester resin products were obtained. Each was blended with a bisphenol F based epoxy resin at two different …

Entrepreneurially Minded Learning In The Unit Operations Laboratory Through Community Engagement In A Blended Teaching Environment, Erick S. Vasquez, Kelly Bohrer, Abraham Noe-Hays, Arthur Davis, Matthew Dewitt, Michael J. Elsass

Chemical and Materials Engineering Faculty Publications

Online and blended learning opportunities in Chemical Engineering curriculum emerged due to COVID-19. After eight weeks of in-person Unit Operations Laboratory sessions, a remote-learning open-ended final project was assigned to student teams. The assignment involved aspects related to entrepreneurial-minded learning (EML) and community-based learning (CBL). Results show correlations between self-directed learning and the EML framework. Continuous support and involvement of a community partner correlate to students' m

Analytical Model For Electromagnetic Induction In Pulsating Ferrofluid Pipe Flows, Huiyu Wang, John G. Monroe, Swati Kumari, Serhiy O. Leontsev, Erick S. Vasquez, Scott M. Thompson, Matthew J. Berg, Dibbon Keith Walters, Keisha B. Walters

Chemical and Materials Engineering Faculty Publications

No abstract provided.

Facile Fabrication And Characterization Of Kraft Lignin@Fe3o4 Nanocomposites Using Ph Driven Precipitation: Effects On Increasing Lignin Content, Frankie A. Petrie, Justin M. Gorham, Robert T. Busch, Serhiy O. Leontsev, Esteban E. Ureña-Benavides, Erick S. Vasquez

Chemical and Materials Engineering Faculty Publications

This work offers a facile fabrication method for lignin nanocomposites through the assembly of kraft lignin onto magnetic nanoparticles (Fe3O4) based on pH-driven precipitation, without needing organic solvents or lignin functionalization. Kraft lignin@Fe3O4 multicore nanocomposites fabrication proceeded using a simple, pH-driven precipitation technique. An alkaline solution for kraft lignin (pH 12) was rapidly injected into an aqueous-based Fe3O4 nanoparticle colloidal suspension (pH 7) under constant mixing conditions, allowing the fabrication of lignin magnetic nanocomposites. The effects of increasing lignin to initial Fe3O4 mass content (g/g), increasing in ratio from 1:1 to 20:1, are discussed with a complete chemical, structural, and …

Comparison Of Tensile Properties Of Triaxial Braided Carbon Fiber Composites Made From Vacuum Assisted Resin Transfer Molding (Vartm) And Autoclave Molding, Donald A. Klosterman, Charles Browning

Chemical and Materials Engineering Faculty Publications

Triaxially braided fiber composites are increasingly being used in aerospace, ballistic, and sporting good applications due to their inherent damage tolerance, torsional stability, and cost compared to woven fabrics and unidirectional preforms. There have been numerous publications over the past 15-20 years on the mechanical properties and failure mechanisms of triaxial braided composites. However, most of these have involved panels made with autoclave curing. In the present study, braided carbon fiber composites were made using autoclave curing and vacuum assisted resin transfer molding (VARTM). The goal of the study was to compare the physical and tensile properties of quasi-isotropic panels …

Detection And Aggregation Of Listeria Monocytogenes Using Polyclonal Antibody Gold-Coated Magnetic Nanoshells Surface-Enhanced Raman Spectroscopy Substrates, Robert T. Busch, Farzia Karim, Yvonne Sun, H. Christopher Fry, Yuzi Liu, Chenglong Zhao, Erick S. Vasquez

Chemical and Materials Engineering Faculty Publications

Magnetic nanoshells with tailored surface chemistry can enhance bacterial detection and separation technologies. This work demonstrated a simple technique to detect, capture, and aggregate bacteria with the aid of end-functionalized polyclonal antibody gold-coated magnetic nanoshells (pAb-Lis-AuMNs) as surface-enhanced Raman spectroscopy (SERS) probes. Listeria monocytogenes were used as the pathogenic bacteria and the pAb-Lis-AuMNs, 300 nm diameter, were used as probes allowing facile magnetic separation and aggregation. An optimized covalent bioconjugation procedure between the magnetic nanoshells and the polyclonal antibody was performed at pH six via a carbodiimide crosslinking reaction. Spectroscopic and morphological characterization techniques confirmed the fabrication of stable pAb-Lis-AuMNs. …

Fabrication And Characterization Of Electrospun Poly(Acrylonitrile-Co-Methyl Acrylate)/Lignin Nanofibers: Effects Of Lignin Type And Total Polymer Concentration, Suchitha Devadas, Saja M. Nabat Al-Ajrash, Donald A. Klosterman, Kenya A. Crosson, Garry S. Crosson, Erick S. Vasquez

Chemical and Materials Engineering Faculty Publications

Lignin macromolecules are potential precursor materials for producing electrospun nanofibers for composite applications. However, little is known about the effect of lignin type and blend ratios with synthetic polymers. This study analyzed blends of poly(acrylonitrile-co-methyl acrylate) (PAN-MA) with two types of commercially available lignin, low sulfonate (LSL) and alkali, kraft lignin (AL), in DMF solvent. The electrospinning and polymer blend solution conditions were optimized to produce thermally stable, smooth lignin-based nanofibers with total polymer content of up to 20 wt % in solution and a 50/50 blend weight ratio. Microscopy studies revealed that AL blends possess good solubility, miscibility, and …