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Full-Text Articles in Biochemical and Biomolecular Engineering

Silver Nanoparticle Coated Bioactive Glasses - Composites With Dex/Cmc Hydrogels: Characterization, Solubility, And In Vitro Biological Studies, Anthony W. Wren, Pegah Hassanzadeh, Lana M. Placek, Timothy J. Keenan, Aisling Coughlan, Lydia R. Boutelle, Mark R. Towler Aug 2015

Silver Nanoparticle Coated Bioactive Glasses - Composites With Dex/Cmc Hydrogels: Characterization, Solubility, And In Vitro Biological Studies, Anthony W. Wren, Pegah Hassanzadeh, Lana M. Placek, Timothy J. Keenan, Aisling Coughlan, Lydia R. Boutelle, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Silver (Ag) coated bioactive glass particles (Ag-BG) were formulated and compared to uncoated controls (BG) in relation to glass characterization, solubility and microbiology. X-ray diffraction (XRD) confirmed a crystalline AgNP surface coating while ion release studies determined low Ag release (/L). Cell culture studies presented increased cell viability (127 and 102%) with lower liquid extract (50 and 100 ml/ml) concentrations. Antibacterial testing of Ag-BG in E. coli, S. epidermidis and S. aureus significantly reduced bacterial cell viability by 60-90%. Composites of Ag-BG/CMC-Dex Hydrogels were formulated and characterized. Agar diffusion testing was conducted where Ag-BG/hydrogel composites produced the largest inhibition zones …


Bioactive Glass Reinforced Elastomer Composites For Skeletal Regeneration: A Review, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Mark R. Towler Aug 2015

Bioactive Glass Reinforced Elastomer Composites For Skeletal Regeneration: A Review, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Biodegradable elastomers have clinical applicability due to their biocompatibility, tunable degradation and elasticity. The addition of bioactive glasses to these elastomers can impart mechanical properties sufficient for hard tissue replacement. Hence, a composite with a biodegradable polymer matrix and a bio glass filler can offer a method of augmenting existing tissue. This article reviews the applications of such composites for skeletal augmentation.


Effects Of Strontium Substitution On Bioactivity Of Hydroxyapatite, Chokchai Yatongchai, Lana M. Placek, Mark R. Towler, Anthony W. Wren Jun 2015

Effects Of Strontium Substitution On Bioactivity Of Hydroxyapatite, Chokchai Yatongchai, Lana M. Placek, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Effect of strontium (Sr) substitution on bioactivity of hydroxyapatite (HA) was investigated. The substitution of Sr2+ for Ca2+ in the HA lattice increases biodegradability of Sr-substituted HA (Sr-HA) and accelerates the formation of apatite crystals on the Sr-HA surface. Moreover, the dissolution products from HA and Sr-HA samples are not cyto-toxic.


Fabrication And Characterization Of Poly(Octanediol Citrate)/Gallium-Containing Bioglass Microcomposite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Hussin A. Rothan, Rohana Yusof, Mark R. Towler, Ivan Djordjevic Mar 2015

Fabrication And Characterization Of Poly(Octanediol Citrate)/Gallium-Containing Bioglass Microcomposite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Hussin A. Rothan, Rohana Yusof, Mark R. Towler, Ivan Djordjevic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bone can be affected by osteosarcomae requiring surgical excision of the tumor as part of the treatment regime. Complete removal of cancerous cells is difficult and conventionally requires the removal of a margin of safety around the tumor to offer improved patient prognosis. This work considers a novel series of composite scaffolds based on poly (octanediol citrate) (POC) impregnated with gallium-based bioglass microparticles for possible incorporation into bone following tumor removal. The objective of this research was to fabricate and characterize these scaffolds and subsequently report on their mechanical and biological properties. The porous micro composite scaffolds with various concentrations …


A Glass Polyalkenoate Cement Carrier For Bone Morphogenetic Proteins, Adel M.F. Alhalawani, Omar Rodriguez, Declan J. Curran, Russell Co, Sean Kieran, Saad Arshad, Timothy J. Keenan, Anthony W. Wren, Gazelle Crasto, Sean A.F. Peel, Mark R. Towler Mar 2015

A Glass Polyalkenoate Cement Carrier For Bone Morphogenetic Proteins, Adel M.F. Alhalawani, Omar Rodriguez, Declan J. Curran, Russell Co, Sean Kieran, Saad Arshad, Timothy J. Keenan, Anthony W. Wren, Gazelle Crasto, Sean A.F. Peel, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This work considers a glass polyalkenoate cement (GPC)-based carrier for the effective delivery of bone morphogenetic proteins (BMPs) at an implantation site. A 0.12 CaO–0.04 SrO–0.36 ZnO–0.48 SiO2 based glass and poly(acrylic acid) (PAA, Mw 213,000) were employed for the fabrication of the GPC. The media used for the water source in the GPC reaction was altered to produce a series of GPCs. The GPC liquid media was either 100 % distilled water with additions of albumin at 0, 2, 5 and 8 wt% of the glass content, 100 % formulation buffer (IFB), and 100 % BMP (150 µg …


Highly Porous Titania Films Coated On Sub-Micron Particles With Tunable Thickness By Molecular Layer Deposition In A Fluidized Bed Reactor, Rajankumar L. Patel, Ying Bing Jiang, Xinhua Liang Mar 2015

Highly Porous Titania Films Coated On Sub-Micron Particles With Tunable Thickness By Molecular Layer Deposition In A Fluidized Bed Reactor, Rajankumar L. Patel, Ying Bing Jiang, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Titanium alkoxide (titanicone) thin films were coated on large quantities of sub-micron sized silica particles at 100 °C using molecular layer deposition (MLD) in a fluidized bed reactor. Titanium tetrachloride and ethylene glycol were used as precursors. The content of titanium on the particles increased linearly as the number of MLD coating cycles increased. The conformity of the films, with a thickness of ~12 nm, was verified using TEM for silica particles coated with 50 cycles of titanicone. The composition of the titan cone films was confirmed using energy dispersive X-ray spectrometry. Porous titanium oxide films were formed for the …


Impact Of Internals Size And Configuration On Bubble Dynamics In Bubble Columns For Alternative Clean Fuels Production, Moses Kagumba, Muthanna H. Al-Dahhan Feb 2015

Impact Of Internals Size And Configuration On Bubble Dynamics In Bubble Columns For Alternative Clean Fuels Production, Moses Kagumba, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bubble Columns Have Been Used in a Wide Range of Applications in Industry Including the Production of Alternative Clean Fuels Via Fischer-Tropsch Synthesis and Liquid Phase Methanol Synthesis, among Others. the Effects of Dense Internals Encountered in Fischer-Tropsch Synthesis with Different Diameters and Covering the Same Cross-Sectional Area and Hence Configuration on Bubble Properties Are Lacking in the Open Literature. Therefore, the Focus of This Study is to Investigate the Effects of Dense Internals with Different Diameters and Covering the Same Cross-Sectional Area and Hence Configuration on the Bubble Dynamics Such as Local and overall Gas Holdup, Specific Interfacial Area, …


Process For The Preparation Of Sufentanil Base And Related Components, Brian Orr, Joseph P. Haar Jr., George H. Klemm, Keith Tomazi Feb 2015

Process For The Preparation Of Sufentanil Base And Related Components, Brian Orr, Joseph P. Haar Jr., George H. Klemm, Keith Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The present disclosure generally related to an improved process for the preparation of various piperidine derivatives. More particularly, the present disclosure related to an improved process for preparing sufentanil base (1) and related compounds, which advantageously utilizes more cost effective and/or less hazardous reagents, including a dispersion comprising between about 50% and about 70% by weight (based on the total weight of the dispersion) of an alkali metal hydride, such as sodium hydride, as well as eliminates the need for expensive and/or time consuming purification techniques.


Investigating The Solubility And Cytocompatibility Of Cao-Na2o-Sio2/Tio2 Bioactive Glasses, Anthony W. Wren, Aisling Coughlan, Courtney M. Smith, Sarah P. Hudson, Fathima R. Laffir, Mark R. Towler Feb 2015

Investigating The Solubility And Cytocompatibility Of Cao-Na2o-Sio2/Tio2 Bioactive Glasses, Anthony W. Wren, Aisling Coughlan, Courtney M. Smith, Sarah P. Hudson, Fathima R. Laffir, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study aims to investigate the solubility of a series of titanium (TiO2)-containing bioactive glasses and their subsequent effect on cell viability. Five glasses were synthesized in the composition range SiO2-Na2O-CaO with 5 mol % of increments TiO2 substituted for SiO2. Glass solubility was investigated with respect to (1) exposed surface area, (2) particle size, (3) incubation time, and (4) compositional effects. Ion release profiles showed that sodium (Na+) presented high release rates after 1 day and were unchanged between 7 and 14 days. Calcium (Ca2+) release …


Effect Of Nitrogen On Properties Of Na2o-Cao-Sro-Zno-Sio2 Glasses, Ahmed Bachar, Cyrille Mercier, Arnaud Tricoteaux, Jean Christophe Hornez, Anne Leriche, Claudine Follet, Bertrand Revel, Stuart Hampshire, Mark R. Towler Jan 2015

Effect Of Nitrogen On Properties Of Na2o-Cao-Sro-Zno-Sio2 Glasses, Ahmed Bachar, Cyrille Mercier, Arnaud Tricoteaux, Jean Christophe Hornez, Anne Leriche, Claudine Follet, Bertrand Revel, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glasses in the Na2O-CaO-SrO-ZnO-SiO2 system have previously been investigated for suitability as a reagent in Al-free glass polyalkenoate cements (GPCs). These materials have many properties that offer potential in orthopedics. However, their applicability has been limited, to date, because of their poor strength. This study was undertaken with the aim of increasing the mechanical properties of a series of these Zn-based GPC glasses by doping with nitrogen to give overall compositions of: 10Na2O-10CaO-20SrO-20ZnO-(40-3x)SiO2-xSi3N4 (x is the no. of moles of Si3N4). The density, glass-transition temperature, hardness, …


Effect Of Resin Thickness, And Curing Time On The Micro-Hardness Of Bulk-Fill Resin Composites, Shaymaa M. Nagi, Lamiaa M. Moharam, Mohamed H. Zaazou Jan 2015

Effect Of Resin Thickness, And Curing Time On The Micro-Hardness Of Bulk-Fill Resin Composites, Shaymaa M. Nagi, Lamiaa M. Moharam, Mohamed H. Zaazou

Chemical and Biochemical Engineering Faculty Research & Creative Works

Background: Bulk-fill resin composite has been introduced, their manufacturers claimed that they can be applied in bulks of 4mm, without necessitating a prolonged curing time, or a light curing unit with increased irradiance. Thus, this study was conducted to evaluate the effect of resin thickness and curing time on the micro-hardness of two bulk -fill resin composites: Tetric Evo-Ceram [TE], and X-trafil [XF]. Material and Methods: 120 cylindrical specimens were prepared and divided into 24 groups (n=5/group), representing the two bulk-fill resin composites, three different material thicknesses (2, 3 and 4 mm) and the four curing times used in the …


Processing And Mechanical Testing Of Strontium-Substituted Hydroxyapatite/Glass Composites, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren Dec 2014

Processing And Mechanical Testing Of Strontium-Substituted Hydroxyapatite/Glass Composites, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Sr-HA/Glass composites were produced. Phase composition of composites was evaluated. Their physical and mechanical properties were determined. Sintered composites mainly consisted of Sr-HA/β-TCP, or β-TCP/Ca2ZnSi2O7. The composites had porosity up to 4 times those of undoped Sr-HA. Compared to undoped Sr-HA, the Sr-HA/Glass composites had lower biaxial flexural strength and hardness. The Weibull modulus for the composites ranged from 2.77 to 18.74.


Porous Titania Microspheres With Uniform Wall Thickness And High Photoactivity, Xinhua Liang, Rajankumar L. Patel Mar 2014

Porous Titania Microspheres With Uniform Wall Thickness And High Photoactivity, Xinhua Liang, Rajankumar L. Patel

Chemical and Biochemical Engineering Faculty Research & Creative Works

Highly porous titania particles were prepared by depositing thin films of titania, using alternating reactions of TiCl4 and hydrogen peroxide, on poly(styrene-divinylbenzene) (PS-DVB) template particles via atomic layer deposition (ALD) at 77 C. The composition of the titania films was verified by XPS analysis, and the titania films were directly observed by TEM. TGA/DSC was used to study the thermal decomposition of the polymer template. Porous titania particles with uniform wall thicknesses were successfully obtained after the template PS-DVB was removed by oxidation in air at 400 C for 24 h. Verification of the resulting porous structure of the titania …


Catalytic Hydrogen Transfer Of Ketones Over Atomic Layer Deposited Highly-Dispersed Platinum Nanoparticles Supported On Multi-Walled Carbon Nanotubes, Chengjun Jiang, Xinhua Liang Feb 2014

Catalytic Hydrogen Transfer Of Ketones Over Atomic Layer Deposited Highly-Dispersed Platinum Nanoparticles Supported On Multi-Walled Carbon Nanotubes, Chengjun Jiang, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hydrogen transfer of ketones, catalyzed by highly dispersed platinum nanoparticles supported on multi-walled carbon nanotubes (MWCNTs), was studied. Pt nanoparticles were deposited on gram quantities of non-functionalized MWCNTs by atomic layer deposition (ALD) at 300 C, using (methylcyclopentadienyl) trimethylplatinum and oxygen as precursors. TEM analysis showed that ~ 1.4 nm Pt nanoparticles were highly dispersed on MWCNTs. The heterogeneous hydrogen-transfer reactions of acetophenone indicated that an acetophenone conversion of 100% and a 1-phenylethanol selectivity of 99.0% could be obtained with a ketone to Pt mass ratio of 24,690 and a ketone to KOH mass ratio of 22 at 150 C …


Multiphase Hydrodynamics And Distribution Characteristics In A Monolith Bed Measured By Optical Fiber Probe, Yuan Zhou, Milorad P. Dudukovic, Muthanna H. Al-Dahhan, Hui Liu Feb 2014

Multiphase Hydrodynamics And Distribution Characteristics In A Monolith Bed Measured By Optical Fiber Probe, Yuan Zhou, Milorad P. Dudukovic, Muthanna H. Al-Dahhan, Hui Liu

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Optical Fiber Probe Has Been for the First Time Applied to Investigate the Hydrodynamics and Gas-Phase Distribution at High Gas/liquid Ratios in a Two-Phase Flow Monolith Bed with 0.048 M Diameter and 400 Cpsi. Local Hydrodynamic Parameters Including Gas Holdup, Bubble Frequency, Bubble Velocity, and Bubble Length in Single Channels Were Measured by 16 Inserted Single-Point Optical Fiber Probes within the Bed under a Nozzle as the Liquid Distributor. the Following Findings Are Reported. (1) the Optical Fiber Probe Can Be Used as an Efficient and Convenient Technique for Measuring Local Hydrodynamic Parameters Inside the Channels of a Monolith …


Environmental Stress Cracking Of Glassy Polymers, Parthasakha Neogi, Gholamreza Zahedi Jan 2014

Environmental Stress Cracking Of Glassy Polymers, Parthasakha Neogi, Gholamreza Zahedi

Chemical and Biochemical Engineering Faculty Research & Creative Works

When a glassy polymer is exposed to an organic solvent, it can crack spontaneously or fail more readily under extension. This is environmental stress cracking. When the solvent diffuses into the polymer, stresses develop because of swelling of the polymer. In addition, fluctuations give rise to stresses, because of the variation in surface tension from changes in the surface concentration of the solute, which is the Marangoni effect. A linear stability analysis is performed to show that such a system is unstable to infinitesimal disturbances. Large tensile stresses arise locally, leading to failures, which will be observed in the interfacial …


Process For The Purification Of Benzphetamine Hydrochloride, Keith Tomazi Jan 2014

Process For The Purification Of Benzphetamine Hydrochloride, Keith Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The present invention relates to the economical and separation of benzphetamine hydrochloride and methamphetamine by liquid extraction. An extraction process employing a suitable organic solvent and water at a pH in the range of from about 6 to about 8 provides excellent removal of the methamphetamine by dissolution in the water phase while the benzphetamine dissolves in the organic phase. Simple separation of the two phases results in separation of the two amines.


Investigating The Effect Of Sio2-Tio2-Cao-Na 2o-Zno Bioactive Glass Doped Hydroxyapatite: Characterisation And Structural Evaluation, Chokchai Yatongchai, Anthony W. Wren, Declan J. Curran, Stuart Hampshire, Mark R. Towler Jan 2014

Investigating The Effect Of Sio2-Tio2-Cao-Na 2o-Zno Bioactive Glass Doped Hydroxyapatite: Characterisation And Structural Evaluation, Chokchai Yatongchai, Anthony W. Wren, Declan J. Curran, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of increasing bioactive glass additions,

SiO2-TiO2-CaO-Na2O-ZnO up to 25 wt% in increments of 5 wt%, on the physical and mechanical properties of hydroxyapatite (HA) sintered at 900, 1000, 1100 and 1200°C for 2 h was investigated. Increasing both the glass content and the temperature resulted in increased HA decomposition. This resulted in the formation of a number of bioactive phases. However the presence of the liquidus glass phase did not result in increased densification levels. At 1000 and 1100°C the additions of 5 wt% glass resulted in a decrease in density which …


Degradable Borate Glass Polyalkenoate Cements, L. Shen, A. Coughlan, Mark R. Towler, M. Hall Jan 2014

Degradable Borate Glass Polyalkenoate Cements, L. Shen, A. Coughlan, Mark R. Towler, M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) containing aluminum-free borate glasses having the general composition Ag2O-Na2O-CaO-SrO-ZnO- TiO2-B2O3 were evaluated in this work. An initial screening study of sixteen compositions was used to identify regions of glass formation and cement compositions with promising rheological properties. The results of the screening study were used to develop four model borate glass compositions for further study. A second round of rheological experiments was used to identify a preferred GPC formulation for each model glass composition. The model borate glasses containing higher levels of TiO2 (7.5 mol %) …


Stereoselective Transformations Of Α-Trifluoromethylated Ketoximes To Optically Active Amines By Enzyme-Nanometal Cocatalysis: Synthesis Of (S)-Inhibitor Of Phenylethanolamine N-Methyltransferase, Guilin Cheng, Qi Wu, Zeyu Shang, Xinhua Liang, Xianfu Lin Jan 2014

Stereoselective Transformations Of Α-Trifluoromethylated Ketoximes To Optically Active Amines By Enzyme-Nanometal Cocatalysis: Synthesis Of (S)-Inhibitor Of Phenylethanolamine N-Methyltransferase, Guilin Cheng, Qi Wu, Zeyu Shang, Xinhua Liang, Xianfu Lin

Chemical and Biochemical Engineering Faculty Research & Creative Works

One-pot cascade synthesis of optically active α-trifluoro methylated amines directly from ketoximes was accomplished with the use of Candida antarctica lipase B and catalysts prepared by atomic layer deposition (ALD). Compared to the commercial palladium catalyst, the ALD-prepared catalysts showed much higher activity and afforded various α-trifluoro methylated amides in good yields and with high enantioselectivity. One of the enantiopure amides was further hydrolyzed into the corresponding amine, which was treated as a crucial starting material for total synthesis of (S)-inhibitor of phenyl ethanolamine N-methyltransferase without loss of chiral information. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Characteristics Of Glass Ionomer Cements Composed Of Glass Powders In Cao-Sro-Zno-Sio2 System Prepared By Two Different Synthetic Routes, Ill Yong Kim, Chikara Ohtsuki, Aisling Coughlan, Lana Placek, Anthony W. Wren, Mark R. Towler Dec 2013

Characteristics Of Glass Ionomer Cements Composed Of Glass Powders In Cao-Sro-Zno-Sio2 System Prepared By Two Different Synthetic Routes, Ill Yong Kim, Chikara Ohtsuki, Aisling Coughlan, Lana Placek, Anthony W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass ionomer cements (GICs) are composed of an acid degradable glass, polyacrylic acid and water. Sol-gel processing to prepare the glass phase has certain advantages, such as the ability to employ lower synthesis temperatures than melt quenching and glasses that are reported to have higher purity. A previous study reported the effects of glass synthesis route on GIC fabrication. However, in that study, the sol-gel derived glass exhibited a reduced concentration of cations. This study investigates increasing the cation content of a sol-gel derived glass, 12CaO·4SrO·36ZnO·48SiO2 (molar ratio) by heating before aging to reduce dissolution of cations. This glass …


Relating Ph And Ion Release From Ga2o3-Na 2o-Cao-Zno-Sio2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, Mark R. Towler, M. M. Hall Nov 2013

Relating Ph And Ion Release From Ga2o3-Na 2o-Cao-Zno-Sio2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, Mark R. Towler, M. M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three glasses were designed for this study, including one Ga-free glass (Control), and two Ga-containing glasses (TGa-1, TGa-2). In the Ga-containing glasses, Ga2O3 is included at the expense of ZnO. This study focuses on the relation between pH and ion concentration present in solution in which these bioactive glasses have been submerged for periods of 1, 7, and 14 days. © 2013 IEEE.


Gallium Containing Glass Polyalkenoate Bone Cements: Ion Release And E. Coli Inhibition, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler Nov 2013

Gallium Containing Glass Polyalkenoate Bone Cements: Ion Release And E. Coli Inhibition, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Glass Polyalkenoate Cement (GPC) series (LCon., LGa-1 and LGa-2) containing gallium (Ga) and a 50 wt% addition of E11 polyacrylic acid (PAA), previously developed, was evaluated for ion release, specifically Si, Ca, Zn and Ga, and E. coli inhibition. The maximum inhibition was observed in the t = 0 samples and was 0.35 mm for LCon. and 0.65 mm for LGa-1 and LGa-2. © 2013 IEEE.


Biocompatibility Of Cao-Na2o-Sio2/Tio2 Glass Ceramic Scaffolds For Orthopaedic Applications, A. W. Wren, A. Coughlan, K. E. Smale, S. T. Misture, B. P. Mahon, O. M. Clarkin, Mark R. Towler Nov 2013

Biocompatibility Of Cao-Na2o-Sio2/Tio2 Glass Ceramic Scaffolds For Orthopaedic Applications, A. W. Wren, A. Coughlan, K. E. Smale, S. T. Misture, B. P. Mahon, O. M. Clarkin, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This work aims to determine the effect of substituting TiO2 for SiO2 in a 0.62SiO2-Na2O-0.24CaO based glass-ceramic scaffold. High temperature X-ray Diffraction (HT-XRD) was used to determine the sintering temperature (700oC). Both optical microscopy and x-ray micotomography was used to determine the average pore size (540-680ìm) of each scaffold. Cytocompatibility of each scaffold was conducted using murine mesenchymal stem cells. © 2013 IEEE.


An Investigation Into The Structure And Properties Of Cao-Zno-Sio 2-Tio2-Na2o Bioactive Glass/Hydroxyapatite Composite, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren Nov 2013

An Investigation Into The Structure And Properties Of Cao-Zno-Sio 2-Tio2-Na2o Bioactive Glass/Hydroxyapatite Composite, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Effect of the addition of CaO-ZnO-SiO2-TiO2-Na2O glass as a reinforcing phase on properties of hydroxyapatite/glass composites was investigated. The addition of the glass caused the decomposition of HA phase to tricalcium phosphate, inhibiting densification in the HA/glass composites. However, depending on the glass concentration, some of the glass can act as a sintering aid enhancing the densification in the composites. © 2013 IEEE.


Encapsulation Of Supported Metal Nanoparticles With An Ultra-Thin Porous Shell For Size-Selective Reactions, Zeyu Shang, Rajankumar L. Patel, Brian W. Evanko, Xinhua Liang Oct 2013

Encapsulation Of Supported Metal Nanoparticles With An Ultra-Thin Porous Shell For Size-Selective Reactions, Zeyu Shang, Rajankumar L. Patel, Brian W. Evanko, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A novel nanostructured catalyst with an ultra-thin, porous shell obtained from the thermal decomposition of an aluminum alkoxide film deposited by molecular layer deposition for size-selective reactions was developed. The molecular sieving capability of the porous metal oxide films was verified by examining the liquid-phase hydrogenation of n-hexene versus cis-cyclooctene. © 2013 The Royal Society of Chemistry.


Gas Barrier And Mechanical Properties Of Crosslinked Ethylene Vinyl Acetate Nanocomposites, S. A. Ahmad Ramazani, M. Shafiee, Hossein Abedsoltan, A. Shafiee Oct 2013

Gas Barrier And Mechanical Properties Of Crosslinked Ethylene Vinyl Acetate Nanocomposites, S. A. Ahmad Ramazani, M. Shafiee, Hossein Abedsoltan, A. Shafiee

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this research, the effects of crosslinking agent and clay content on the morphology, barrier and mechanical properties of ethylene vinyl acetate-organoclay nanocomposites prepared by solution method were studied. Dicumyl peroxide has been used as crosslinking agent. The morphology of the prepared nanocomposites was investigated using wide-angle X-ray diffraction and transmission electron microscopy. Wide-angle X-ray diffraction and transmission electron microscopy indicated that the prepared nanocomposites had predominantly intercalated morphologies. The obtained results of permeability tests showed that the permeability of ethylene vinyl acetate films dramatically decreases with addition of organoclay and dicumyl peroxide. Mechanical tests showed that tensile modulus and …


Stabilizing Nanostructured Solid Oxide Fuel Cell Cathode With Atomic Layer Deposition, Yunhui Gong, Diego Palacio, Xueyan Song, Rajankumar L. Patel, Xinhua Liang Sep 2013

Stabilizing Nanostructured Solid Oxide Fuel Cell Cathode With Atomic Layer Deposition, Yunhui Gong, Diego Palacio, Xueyan Song, Rajankumar L. Patel, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

We demonstrate that the highly active but unstable nanostructured intermediate-temperature solid oxide fuel cell cathode, La0.6Sr0.4CoO3-δ (LSCo), can retain its high oxygen reduction reaction (ORR) activity with exceptional stability for 4000 h at 700 C by overcoating its surfaces with a conformal layer of nanoscale ZrO2 films through atomic layer deposition (ALD). The benefits from the presence of the nanoscale ALD-ZrO2 overcoats are remarkable: a factor of 19 and 18 reduction in polarization area-specific resistance and degradation rate over the pristine sample, respectively. The unique multifunctionality of the ALD-derived nanoscaled ZrO2 overcoats, …


Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Ion Release, Biocompatibility And Antibacterial Properties, A. W. Wren, A. Coughlan, M. M. Hall, M. J. German, Mark R. Towler Sep 2013

Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Ion Release, Biocompatibility And Antibacterial Properties, A. W. Wren, A. Coughlan, M. M. Hall, M. J. German, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Ion Release and biocompatibility of a CaO-SrO-ZnO-SiO2 (BT 101) based glass polyalkenoate cement (GPC) was compared against commercial GPCs, Fuji IX and Ketac Molar. The radiopacity (R) was similar for each material, 2.0-2.8. Ion release was evaluated on each material over 1, 7, 30 and 90 days. BT 101 release included Ca (23 mg/L), Sr (23 mg/L) Zn (13 mg/L), Si (203 mg/L). Fuji IX release includes Ca (0.7 mg/L), Al (3 mg/L) Si (26 mg/L), Na (60 mg/L) and P (0.5 mg/L) while Ketac Molar release includes Ca (1 mg/L), Al (0.6 mg/L) Si (23 mg/L), Na (76 …


Atomic Layer Deposited Highly Dispersed Platinum Nanoparticles Supported On Non-Functionalized Multiwalled Carbon Nanotubes For The Hydrogenation Of Xylose To Xylitol, Xinhua Liang, Chengjun Jiang Sep 2013

Atomic Layer Deposited Highly Dispersed Platinum Nanoparticles Supported On Non-Functionalized Multiwalled Carbon Nanotubes For The Hydrogenation Of Xylose To Xylitol, Xinhua Liang, Chengjun Jiang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Highly dispersed platinum nanoparticles were deposited on gram quantities of non-functionalized multiwalled carbon nanotubes (MWCNTs) by atomic layer deposition (ALD) in a fluidized bed reactor at 300°C. (Methylcyclopentadienyl) trimethylplatinum and oxygen were used as precursors. The results of TEM analysis showed that ∼1.3 nm Pt nanoparticles were highly dispersed on non-functionalized MWCNTs. The porous structures of MWCNTs did not change with the deposition of Pt nanoparticles. For comparison, the commercial 3 wt.% Pt/C catalyst was also characterized. The ALD-prepared Pt/MWCNT was used for the hydrogenation of xylose to xylitol. The ALD-prepared Pt/MWCNT showed the best catalytic performance with 100 % …