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Full-Text Articles in Chemistry

Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown Sep 2019

Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown

Sarah Cady

In this study, we methylated hydroxyl groups (phenolic hydroxyl: Phe-OH and aliphatic hydroxyl: Aliph-OH) in soda lignin (SL) prior to solvent liquefaction to improve storage stability of the resulting oil. We investigated two methylating reagents, dimethyl sulfate (DMS) and dimethyl carbonate (DMC), for selective Phe-OH and total hydroxyl group (Phe-OH and Aliph-OH) blocking. Samples of SL, DMS-SL, and DMC-SL were depolymerized into oils under supercritical ethanol (350 °C). Both methylated lignins produced higher amounts of oils and smaller amounts of char compared to untreated SL due to suppressed charring reactions. Oil produced from SL had relatively higher functional group contents …


Recent Approaches In Designing Bioadhesive Materials Inspired By Mussel Adhesive Protein, Pegah Kord Forooshani, Bruce P. Lee Mar 2018

Recent Approaches In Designing Bioadhesive Materials Inspired By Mussel Adhesive Protein, Pegah Kord Forooshani, Bruce P. Lee

Bruce Lee

Marine mussels secret protein-based adhesives, which enable them to anchor to various surfaces in a saline, intertidal zone. Mussel foot proteins (Mfps) contain a large abundance of a unique, catecholic amino acid, Dopa, in their protein sequences. Catechol offers robust and durable adhe-sion to various substrate surfaces and contributes to the curing of the adhesive plaques. In this article, we review the unique features and the key functionalities of Mfps, catechol chemistry, and strategies for preparing catechol-functionalized poly- mers. Specifically, we reviewed recent findings on the contributions of various features of Mfps on interfacial binding, which include coacervate formation, surface …


Improvement Of Mechanical Properties And Water Stability Of Vegetable Protein Based Plastics, Gowrishankar Srinivasan Sep 2015

Improvement Of Mechanical Properties And Water Stability Of Vegetable Protein Based Plastics, Gowrishankar Srinivasan

Gowrishankar Srinivasan

Bio-renewable bio-degradable plastics are a potential solution to the growing problems of pollution caused by petroleum plastics and dependency on foreign nations for petroleum resources. One possible feed stock for these materials are vegetable proteins, especially from soy bean and corn. These proteins have relatively high molecular weights and have the potential of being processed with standard polymer processing technologies. But some issues that need to be addressed are their water instability (soy protein) and inferior mechanical properties as compared to petroleum derived plastics. In this study, soy protein isolates (SPI) and zein protein was processed with various additives and …


Bioactive Surface Modification Of Metal Oxides Via Catechol-Bearing Modular Peptides: Multivalent-Binding, Surface Retention, And Peptide Bioactivity, Wen Tang, Gina Policastro, Geng Hua, Kai Guo, Chrys Wesdemiotis, Gary Doll, Matthew Becker Aug 2015

Bioactive Surface Modification Of Metal Oxides Via Catechol-Bearing Modular Peptides: Multivalent-Binding, Surface Retention, And Peptide Bioactivity, Wen Tang, Gina Policastro, Geng Hua, Kai Guo, Chrys Wesdemiotis, Gary Doll, Matthew Becker

Gary L. Doll

A series of multivalent dendrons containing a bioactive osteogenic growth peptide (OGP) domain and surface-binding catechol domains were obtained through solid phase synthesis, and their binding affinity to hydroxyapatite, TiO2, ZrO2, CeO2, Fe3O4 and gold was characterized using a quartz crystal microbalance with dissipation (QCM-d). Using the distinct difference in binding affinity of the bioconjugate to the metal oxides, TiO2-coated glass slides were selectively patterned with bioactive peptides. Cell culture studies demonstrated the bioavailability of the OGP and that OGP remained on the surface for at least 2 weeks under in vitro cell culture conditions. Bone sialoprotein (BSP) and osteocalcein …


Forensic Significance Of Teal Colored Cashmere And Black Acrylic Fibers, Nicole M. Martin Jul 2015

Forensic Significance Of Teal Colored Cashmere And Black Acrylic Fibers, Nicole M. Martin

Nicole M Martin

Forensic Significance of Teal Colored Cashmere and Black Acrylic Fibers Textile fibers are a valuable type of trace evidence within forensic cases. They have the ability to connect a perpetrator to a victim and or a crime scene. Some types of fibers are more prevalent than others. The purpose of this research was to conduct a target fiber study in order to determine the significance of the selected fibers in a forensic case. Two fibers were selected from two different garments, black acrylic fiber and a teal colored cashmere fiber. Unknown fibers were collected from three local clothing stores and …


Polythiophene Nanocomposites For Photodegradation Applications: Past, Present And Future, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. H. Cho Jun 2015

Polythiophene Nanocomposites For Photodegradation Applications: Past, Present And Future, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. H. Cho

Dr. Mohammad Mansoob Khan

Polythiophene (PTh) has been the subject of considerable interest because of its good environmental stability, unique redox electrical behavior, stability in doped and neutral states, ease of synthesis, and wide range of applications in many fields. Apart from its applications in the electrical or electronic field, PTh has shown promising applications in photocatalytic degradation. The fabrication of a catalyst, metal oxides with PTh, extends the absorption range of the modified composite system, thereby enhancing the photocatalytic activity under UV or visible light irradiation. Substituted PTh, such as alkyl substitution, modifies the electronic properties of the polymer, thereby enlarging the potential …


Improvement Of Mechanical Properties And Water Stability Of Vegetable Protein Based Plastics, Gowrishankar Srinivasan May 2015

Improvement Of Mechanical Properties And Water Stability Of Vegetable Protein Based Plastics, Gowrishankar Srinivasan

Gowrishankar Srinivasan

Bio-renewable bio-degradable plastics are a potential solution to the growing problems of pollution caused by petroleum plastics and dependency on foreign nations for petroleum resources. One possible feed stock for these materials are vegetable proteins, especially from soy bean and corn. These proteins have relatively high molecular weights and have the potential of being processed with standard polymer processing technologies. But some issues that need to be addressed are their water instability (soy protein) and inferior mechanical properties as compared to petroleum derived plastics. In this study, soy protein isolates (SPI) and zein protein was processed with various additives and …


Dc Electrical Conductivity Retention And Electrical Compensation Of Polyaniline By Tio2 At Higher Loading Percentages In Polyaniline@Tio2 Nanocomposites, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. H. Cho Apr 2015

Dc Electrical Conductivity Retention And Electrical Compensation Of Polyaniline By Tio2 At Higher Loading Percentages In Polyaniline@Tio2 Nanocomposites, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. H. Cho

Dr. Mohammad Mansoob Khan

Electrically conductive HCl-doped polyaniline Pani)@titanium dioxide (TiO2) nanocomposites were prepared by the in-situ oxidative polymerization of aniline in the presence of different amounts of TiO2 nanoparticles. The synthesized Pani@TiO2 nanocomposites were confirmed by transmission electron microscopy, X-ray diffraction, UV-visible spectroscopy, and thermogravimetric analysis. The stability of the Pani@TiO2 nanocomposites in terms of their electrical conductivity retention was examined under isothermal and cyclic aging conditions, and compared with that of pure Pani. The Pani@TiO2 nanocomposites showed higher thermal stability than pure Pani. The effect of competitive doping/de-doping by TiO2 was examined at different Pani to TiO2 weight ratios. TiO2 at a …


Synthesis And Polymerization Of (E,E)-[6.2]-(2,5)Furanophane-1,5-Diene, Neil D. Doppler, Jeffrey H. Glans Sep 2014

Synthesis And Polymerization Of (E,E)-[6.2]-(2,5)Furanophane-1,5-Diene, Neil D. Doppler, Jeffrey H. Glans

Jeffrey H. Glans

The goal of this research is to polymerize (E,E)-[6.2]-(2,5)furanophane to give a linear polymer. It will be synthesized by a 1,8-Hofmann Elimination using trimethyl-[(E)-3-(5-methyl-2-furyl)allyl] ammonium iodide. This diene will then be polymerized. The resulting polymeric [3.2] furanophane will then be oxidized to form a polymeric macrocycle tetra ketone. This compound will be tested for cation complexation.


Synthesis And Polymerization Of (E,E)-[6.2]-(2,5)Furanophane-1,5-Diene, Neil D. Doppler, Jeffrey H. Glans Sep 2014

Synthesis And Polymerization Of (E,E)-[6.2]-(2,5)Furanophane-1,5-Diene, Neil D. Doppler, Jeffrey H. Glans

Jeffrey H. Glans

The goal of this research is to polymerize (E,E)-[6.2]-(2,5)furanophane to give a linear polymer. It will be synthesized by a 1,8-Hofmann Elimination using trimethyl-[(E)-3-(5-methyl-2-furyl)allyl] ammonium iodide. This diene will then be polymerized. The resulting polymeric [3.2] furanophane will then be oxidized to form a polymeric macrocycle tetra ketone. This compound will be tested for cation complexation.


Enhanced Thermoelectric Behaviour And Visible Light Activity Of Ag@Tio2/Polyaniline Nanocomposite Synthesized By Biogenic-Chemical Route, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho May 2014

Enhanced Thermoelectric Behaviour And Visible Light Activity Of Ag@Tio2/Polyaniline Nanocomposite Synthesized By Biogenic-Chemical Route, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This paper reports the synthesis of visible light-active Ag@TiO2/Pani nanocomposite through a facile biogenic-chemical route. Ag@TiO2/Pani nanocomposite was prepared by the in-situ oxidative polymerization of aniline in the presence of Ag@TiO2 nanocomposite, which was obtained via a biogenic route. The synthesized Ag@TiO2/Pani nanocomposite was confirmed by UV-visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. The Ag@TiO2/Pani nanocomposite was doped with HCl or para-toluene sulfonic acid to render it conducting. An analysis of the thermoelectrical behavior using a cyclic aging technique showed that the electrical conductivity and thermal stability of Pani got improved after …


Enhanced Thermal Stability Under Dc Electrical Conductivity Retention And Visible Light Activity Of Ag/Tio2@Polyaniline Nanocomposite Film, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, K Raju, J Lee, M. H. Cho May 2014

Enhanced Thermal Stability Under Dc Electrical Conductivity Retention And Visible Light Activity Of Ag/Tio2@Polyaniline Nanocomposite Film, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, K Raju, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The development of organic-inorganic photoactive materials has resulted in significant advancements in heterogeneous visible light photocatalysis. This paper reports the synthesis of visible light-active Ag/TiO2@Pani nanocomposite film via a simple biogenic-chemical route. Electrically conducting Ag/TiO2@Pani nanocomposites were prepared by incorporating Ag/TiO2 in N-methyl-2-pyrrolidone solution of polyaniline (Pani), followed by the preparation of Ag/TiO2@Pani nanocomposite film using solution casting technique. The synthesized Ag/TiO2@Pani nanocomposite was confirmed by UV-visible spectroscopy, photoluminescence spectroscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. The Ag/TiO2@Pani nanocomposite film showed superior activity towards the photodegradation of methylene blue under visible light compared to Pani, …


Polymer Gel Templating Of Free-Standing Inorganic Monoliths For Photocatalysis, Xiaojuan Fan, Honghan Fei, David Demaree, Daniel Brennan, Jessica St. John, Scott Oliver Feb 2014

Polymer Gel Templating Of Free-Standing Inorganic Monoliths For Photocatalysis, Xiaojuan Fan, Honghan Fei, David Demaree, Daniel Brennan, Jessica St. John, Scott Oliver

Xiaojuan Fan

We have developed a simple, low-cost process to fabricate free-standing porous metal oxide monoliths. Various swollen polymers and hydrogels possessing an open network structure are infiltrated with pure liquid metal alkoxide. Hydrolysis followed by chemical or thermal degradation of the polymer leads to bulk porous monoliths, TiO2 and SiO2 as initial examples. The titania solids were subsequently employed as photocatalysts under UV light and monitored for adsorption. The materials show efficient reusable photocatalytic ability as compared to pure-phase nanoparticle titanium oxide.


Introduction To Molecular Motion In Polymers (Book Review), Jeffrey H. Glans Jan 2014

Introduction To Molecular Motion In Polymers (Book Review), Jeffrey H. Glans

Jeffrey H. Glans

A book review by Jeffrey H. Glans. Pethrick, Richard A., T. Amornsakchai, and A. M. North. Introduction to Molecular Motion in Polymers. Dunbeath, Scotland: Whittles Pub.; Boca Raton, FL: Distributed in North America by CRC, 2011. ISBN 9781849950084


Fluorescent Ratiometric Indicators Based On Cu(Ii)-Induced Changes In Poly(Nipam) Microparticle Volume, Shawn Burdette, John Osambo, W.Rudolf Seitz, Daniel Kennedy, Roy Planalp, Aaron Jones, Randy Jackson Jan 2013

Fluorescent Ratiometric Indicators Based On Cu(Ii)-Induced Changes In Poly(Nipam) Microparticle Volume, Shawn Burdette, John Osambo, W.Rudolf Seitz, Daniel Kennedy, Roy Planalp, Aaron Jones, Randy Jackson

Shawn C. Burdette

Microparticles consisting of the thermal responsive polymer N-isopropyl acrylamide (polyNIPAM), a metal ion-binding ligand and a fluorophore pair that undergoes fluorescence resonance energy transfer (FRET) have been prepared and characterized. Upon the addition of Cu(II), the microparticles swell or contract depending on whether charge is introduced or neutralized on the polymer backbone. The variation in microparticle morphology is translated into changes in emission of each fluorophore in the FRET pair. By measuring the emission intensity ratio between the FRET pair upon Cu(II) addition, the concentration of metal ion in solution can be quantified. This ratiometric fluorescent indicator is the newest …


Hyaluronic Acid Based Self-Assembling Nanosystems For Cd44 Target Mediated Sirna Delivery To Solid Tumors., Arun Iyer Dec 2012

Hyaluronic Acid Based Self-Assembling Nanosystems For Cd44 Target Mediated Sirna Delivery To Solid Tumors., Arun Iyer

Arun Iyer

Anticancer therapeutics employing RNA interference mechanism holds promising potentials for sequence-specific silencing of target genes. However targeted delivery of siRNAs to tumor tissues and cells and more importantly, their intracellular release at sites of interest still remains a major challenge that needs to be addressed before this technique could become a clinically viable option. In the current study, we have engineered and screened a series of CD44 targeting hyaluronic acid (HA) based self-assembling nanosystems for targeted siRNA delivery. The HA polymer was functionalized with lipids of varying carbon chain lengths/nitrogen content, as well as polyamines for assessing siRNA encapsulation. From …


Synthesis And Characterization Of Linear And Branched Polylactic Acid For Use In Food Packaging Applications, Kyle C. Bentz Mar 2012

Synthesis And Characterization Of Linear And Branched Polylactic Acid For Use In Food Packaging Applications, Kyle C. Bentz

Kyle C Bentz

Polylactic acid (PLA) resins of various molecular weights and molecular weight distributions were synthesized. Linear, narrow molecular weight distribution (MWD) PLA resins were synthesized, as well as resins containing both high molecular weight branched structures and low molecular weight chains and oligomers. Narrow MWD resins were synthesized for use as adhesives for corrugated paperboard and broad MWD resins were synthesized for use as a waterborne coating. PLA resins were dispersed for use as a waterborne coating. Success has been made at forming films utilizing various plasticizers and surfactants as well as polyvinyl alcohol as dispersing agents. A cold dispersion procedure …


Nanoscale Toughness And Behavior Of Graphene/Epoxy Interfaces, Nima Rahbar, Hossein Salahshoor Dec 2011

Nanoscale Toughness And Behavior Of Graphene/Epoxy Interfaces, Nima Rahbar, Hossein Salahshoor

Nima Rahbar

Atomistic simulations are performed to investigate the nano-scale interfacial fracture toughness between graphene and epoxy. Nano-mechanical properties of graphene and epoxy are initially studied using molecular dynamics simulations. A novel method is suggested to accurately model the behavior of the graphen/epoxy interface during the curing process of the epoxy as a function of temperature. The computed interfacial fracture energy is computed at about 0.203 J/m2, which is in good agreement with available experimental data. It is also shown that the adhesion between cured epoxy and graphene layer increases the pre-existing waviness of the 2-dimensional graphene sheet in a 3-dimensional space. …


Tuning Nonlinear Optical Properties In Π-Delocalizable Ruthenium Complexes, T. Christopher Corkery, Sanjay S. Chavan, Marie P. Cifuentes, Marek Samoc, Stijn Van Cleuvenbergen, Inge Asselberghs, Koen Clays, Mark G. Humphrey Nov 2008

Tuning Nonlinear Optical Properties In Π-Delocalizable Ruthenium Complexes, T. Christopher Corkery, Sanjay S. Chavan, Marie P. Cifuentes, Marek Samoc, Stijn Van Cleuvenbergen, Inge Asselberghs, Koen Clays, Mark G. Humphrey

Chris Corkery

No abstract provided.


Tuning Nonlinear Optical Properties, T. Christopher Corkery, Marie P. Cifuentes, Marek Samok, Mark G. Humphrey Jan 2007

Tuning Nonlinear Optical Properties, T. Christopher Corkery, Marie P. Cifuentes, Marek Samok, Mark G. Humphrey

Chris Corkery

No abstract provided.