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Platinum Group Metal (Pgm) Free Multi Metallic Nanomaterial: A Potential Electrocatalyst For Ethanol Oxidation, Susmita Singh, Prodipta Pal, Soumik Roy, Shalini Basak, Prantica Saha, Anushna Dutta, Sinthia Saha, Mainak Bose

Turkish Journal of Chemistry

Comprehensive studies of the ethanol oxidation reaction (EOR) have shown high interest in fuel cell technologies. As anodecatalysts, introducing platinum group metal (PGM) free catalyst is promising for higher catalytic activity towards the EOR, as these arecost-effective, pollution-tolerant, and suitable for sustainable energy conversion. In this investigation, multi walled carbon nanotube(MWCNT) supported PGM-free electrocatalysts are synthesized by the impregnation reduction method. The atomic structure,composition, and morphology of nanoalloy catalysts are discovered through X-ray diffraction (XRD), Raman spectroscopy and fourier-transform infrared (FTIR) spectroscopy techniques. Electrochemical behaviours have been analysed by cyclic voltammetry (CV), linearsweep voltammetry (LSV), Chronoamperometry (CA), and electrochemical impedance …

Nonadhesive Membranes: Preparation And Characterization Of Modified Phbhx Membranes, Funda Alkan, Murat Demi̇rbi̇lek, Oktay Aydin, Berrak Gümüşkaya Öcal, Neli̇sa Laçi̇n Türkoğlu, Mustafa Türk, Mehmet Ali̇ Onur

Turkish Journal of Chemistry

After abdominal surgery, there is a possibility of adhesions between the abdominal organs and the abdominal wall. Theadhesions can lead to problems such as chronic pain, intestinal blockage, and infertility. To prevent adhesion, antiadhesion patchescan be used. In this study, poly hydroxybutyrate-co-hexanoate membranes were fabricated as antiadhesion patches and modified witheither fatty acids or polyethylene glycol. The homogeneity and protein absorption of the membranes were assessed. The effects onblood coagulation factors were determined and the adhesion-proliferation properties of human fibroblast cells on the membranes weredetermined. The results show that myristic acid slightly increases surface free energy (40.7 ± 4.2 mN/m), …

Preparation And Characterization Of Rhfe/G-C3n4 Nanoparticles For Efficient Hydrolysis Of Sodium Borohydride, Merve Uçar Kaya, Mehmet Yurderi̇, Mehmet Zahmakiran

Turkish Journal of Chemistry

Highly effective graphitic carbon nitride-supported RhFe Nanoparticles (denoted as RhFe/g-C3N4) were prepared using a simple wet impregnation-reduction method for the hydrolysis of sodium borohydride (NaBH4). The obtained RhFe/g-C3N4 catalyst was characterized using advanced analytical/spectroscopic techniques such as inductively coupled plasma-optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Powder X-ray diffraction (P-XRD), X-ray spectroscopy (XPS), and fourier transform infrared spectroscopy (FT-IR). The catalytic activities of RhFe/g-C3N4 catalysts with varying Rh/Fe molar ratios were investigated, demonstrating superior catalytic activity compared to monometallic Rh and Fe. The initial turnover frequency (TOF) value of the Rh0.48Fe0.52/g-C3N4 catalyst was calculated as …

Masking Of Iron And Other Interferences During The Spectrophotometric Analysis Of Aluminum From Soil Samples Using Alizarin Red S, Hafiz Zain Ul Aabidin, Muhammad Inam Ul Hassan, Tariq Yasin, Muhammad Zubair Rahim, Ahsan Amin Bhatti, Hamayun Imtiaz, Asif Raza

Turkish Journal of Chemistry

In whole-rock geochemical analysis, the quantification of aluminum in geological samples is performed using differentanalytical techniques including UV-Vis spectrophotometry. During the spectrophotometric analysis of aluminum utilizing AlizarinRed S, iron causes significant interference, leading to inaccurate measurements of the amount of aluminum in the sample. In caseswhere leached or processed samples contain titanium, interference is also observed. However, appropriate masking agents can removethese interferences. In this study, various masking agents including Tiron, oxalic acid, ascorbic acid, and thioglycolic acid were utilizedfor the masking of iron. Among these masking agents, ascorbic acid proved to be the best candidate for masking iron. A …

Simultaneous Determination Of Sunset Yellow And Tartrazine In Real Samples On An N-Butylamine-Graphite/Polyaminophenol Composite Electrode, Mürşi̇de Ceren Afşar, Zekerya Dursun

Turkish Journal of Chemistry

A composite electrode was fabricated for simultaneous determination of sunset yellow (SY) and tartrazine (Tz) in foods andsyrup. It is based on n-butylamine intercalation into graphite and then dropped on a poly (4-aminophenol)/glassy carbon electrode(GCE). The electrode surface morphologies, chemistry, and electrical properties were identified by scanning electron microscopy(SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS), and electrochemical impedance spectroscopy (EIS). Thenew composite electrode significantly increased the electrochemical response of SY and Tz relative to a bare GCE. The peak currentof SY and Tz increased linearly depending on their concentrations from 0.006 μmol L–1 to 1.0 μmol L–1 (r = …

A New Water-Soluble Silicon Phthalocyanine That Catalyzes The Photodegradation Of Pollutant Dyes, Damla Nur Kaya, Behi̇ce Sebnem Sesalan

Turkish Journal of Chemistry

The removal of color arising from water-soluble dyes in wastewaters is necessary to counter the threat to health. Because of thedifficulty in elimination of these dyes by conventional methods, their photodegradation using photosensitizers such as phthalocyanines(Pcs) has been employed recently. When compared to peripherally substituted derivatives, silicon Pcs are reported to be morebiocompatible with low toxicity. Thus a new silicon Pc substituted with two quaternized dimethylamino phenoxy units (compound 1)and its quaternized derivative (compound 2) were synthesized to test its photocatalytic ability employing the dyes methylene blue (MB),eosin B (EB), erythrosine (ERB), sulforhodamine B (SRB), and brilliant blue FCF (BRB), …

Tailor-Designed Oxalic Acid-Crosslinked Poly(Vinyl Alcohol)/Chitosan Biodegradable Films For Active Food Packaging Applications, Reem Hazem Fathy Anwar Elaasar

Theses and Dissertations

Food packaging plastic waste is posing great threats to ecosystems, human health, and the planet's overall sustainability; therefore, research has been directed towards the fabrication of biodegradable food packaging materials. In this study, active and biodegradable oxalic acid (OA) crosslinked poly(vinyl alcohol) (PVA)/chitosan (CS) composite films of different weight ratios were synthesized via the solvent casting technique and their food packaging properties were investigated. Owing to its water resistance and antibacterial superiority, the composite film with the ratio of OA chemically crosslinked PVA/CS 80:20 was elected to be coated with green tea extract (GTE) to ameliorate its antibacterial and antioxidant …

Super-Resolution Imaging Reveals Resistance To Mass Transfer In Functionalized Stationary Phases, Ricardo Monge Neria, Muhammad Zeeshan, Aman Kapoor, Tae Kyong John Kim, Nichole Hoven, Jeffrey S. Pigott, Burcu Gurkan, Christine E. Duval, Lydia Kisley

Faculty Scholarship

Chemical separations are costly in terms of energy, time, and money. Separation methods are optimized with inefficient trial-and-error approaches that lack insight into the molecular dynamics that lead to the success or failure of a separation and, hence, ways to improve the process. We perform super-resolution imaging of fluorescent analytes in five different commercial liquid chromatography materials. Unexpectedly, we observe that chemical functionalization can block more than 50% of the material’s porous interior, rendering it inaccessible to small-molecule analytes. Only in situ imaging unveils the inaccessibility when compared to the industry-accepted ex situ characterization methods. Selectively removing some of the …

Mutational Scanning And Binding Free Energy Computations Of The Sars-Cov-2 Spike Complexes With Distinct Groups Of Neutralizing Antibodies: Energetic Drivers Of Convergent Evolution Of Binding Affinity And Immune Escape Hotspots, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Nishank Raisinghani, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The rapid evolution of SARS-CoV-2 has led to the emergence of variants with increased immune evasion capabilities, posing significant challenges to antibody-based therapeutics and vaccines. In this study, we conducted a comprehensive structural and energetic analysis of SARS-CoV-2 spike receptor-binding domain (RBD) complexes with neutralizing antibodies from four distinct groups (A–D), including group A LY-CoV016, group B AZD8895 and REGN10933, group C LY-CoV555, and group D antibodies AZD1061, REGN10987, and LY-CoV1404. Using coarse-grained simplified simulation models, rapid energy-based mutational scanning, and rigorous MM-GBSA binding free energy calculations, we elucidated the molecular mechanisms of antibody binding and escape mechanisms, identified key …

Quantitative Characterization And Prediction Of The Binding Determinants And Immune Escape Hotspots For Groups Of Broadly Neutralizing Antibodies Against Omicron Variants: Atomistic Modeling Of The Sars-Cov-2 Spike Complexes With Antibodies, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Nishank Raisinghani, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

A growing body of experimental and computational studies suggests that the cross-neutralization antibody activity against Omicron variants may be driven by the balance and tradeoff between multiple energetic factors and interaction contributions of the evolving escape hotspots involved in antigenic drift and convergent evolution. However, the dynamic and energetic details quantifying the balance and contribution of these factors, particularly the balancing nature of specific interactions formed by antibodies with epitope residues, remain largely uncharacterized. In this study, we performed molecular dynamics simulations, an ensemble-based deep mutational scanning of SARS-CoV-2 spike residues, and binding free energy computations for two distinct groups …

Epr Imaging Workshop: From Theory And Practice To Applications, Arthur H. Heiss, Ralph T. Weber, Sandra S. Eaton, Gareth R. Eaton

TeachEPR Submissions

Methods of imaging and insights from imaging are described. Practical aspects of sample type and dimensions are described.

Workshop presented at the 27th International EPR Symposium, sponsored by Bruker BioSpin EPR Division and the University of Denver, in Denver, Colorado on August 1, 2004.

Workshop On The Epr Of Aqueous Samples, Gareth R. Eaton

TeachEPR Submissions

The problem with water and other materials that absorb microwave energy are described. Dielectric properties are described as a function of frequency.

Workshop presented at the 25th International EPR Symposium on July 28, 2002.

Electro-Oxidative Deoxyfluorination Of Arenes With Net3·3hf, En Chih Liu, Sabrina M. Reich, Mayank Tanwar, Matthew Neurock, Long Luo, Melanie S. Sanford

Chemistry Faculty Research & Creative Works

This report describes the design, development, and optimization of an electrochemical deoxyfluorination of arenes using a tetrafluoropyridine-derived leaving group. NEt₃·3HF serves as the fluoride source, and the reactions are conducted using either constant potential or constant current electrolysis in an undivided electrochemical cell. Mechanistic studies support a net oxidative pathway, in which initial single-electron oxidation generates a radical cation intermediate that is trapped by fluoride. The resulting radical undergoes a second oxidation reaction, followed by the loss of the leaving group to yield the fluoroarene product.

Infrared Cooling In An Anharmonic Cascade Framework: 2-Cyanoindene, The Smallest Cyano-Pah Identified In Tmc-1, Mark H. Stockett, Vincent J. Esposito, Eleanor K. Ashworth, Ugo Jacovella, James N. Bull

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Infrared (IR) cooling of polycyclic aromatic hydrocarbon (PAH) molecules is a major radiative stabilization mechanism of PAHs present in space and is the origin of the aromatic infrared bands (AIBs). Here, we report an anharmonic cascade model in a master equation framework to model IR emission rates and emission spectra of energized PAHs as a function of internal energy. The underlying (simple harmonic cascade) framework for fundamental vibrations has been developed through the modeling of cooling rates of PAH cations and other carboneaous ions measured in electrostatic ion storage ring experiments performed under “molecular cloud in a box” conditions. The …

Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter

Engineering Faculty Articles and Research

With the expanding use of polymers in additive manufacturing, sustainable resins for use in vat photopolymerization are required to reduce their environmental impact. One promising approach to achieve this is to incorporate biobased fillers that replace the acrylates in photopolymer resins as ‘green’ alternatives. In this study, photopolymer composites consisting of a methacrylate resin with varying calcium carbonate powder content between 0 and 50 wt.% were investigated. A digital light processing technique was used to fabricate tensile test specimens for mechanical testing. Good printability, dimensional accuracy, and good interlayer adhesion were observed for composite resin formulations that incorporated calcium carbonate …

Effective Learning Strategies In Stem, Muzammil Arshad, Rebecca R. Romatoski, Mamoona Muzammil

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Effective learning strategies were developed, implemented, and applied at five separate institutions of higher education in the United States, and one in the Middle East. The research has been dedicated to determining effective learning strategies for student learning and success. The research series developed grading rubric for homework and exams, developed a course structure for hybrid and face-to-face courses in STEM, and studied the impact of the syllabus design on student learning and motivation. A pedagogical methodology constituting the designed course structure was utilized to use various activity-based modules. Course lectures were designed to utilize PowerPoint presentations and/or OneNote as …

Dft Study Of The Mechanism Of Selective Hydrogenation Of Acetylene By Rhodium Single-Atom Catalyst Supported On Hy Zeolite, Melisa Su Yordanlı, Roberto Escobar, Jessica Meza, Deniz Akgül, Yuxin Zhao, Alper Uzun, Fatma Ahu Akin, Viktorya Aviyente, Abdurrahman Cagri Atesin, Tülay A. Ateşin

School of Earth, Environmental, & Marine Sciences Faculty Publications

The selectivity of acetylene hydrogenation by the Rh single-atom catalyst (SAC) supported on HY zeolite was investigated using density functional theory (DFT) and a 5/83T quantum mechanics/molecular mechanics (QM/MM) embedded cluster model. The calculated activation barrier (ΔG‡) for the oxidative addition of dihydrogen to the Rh metal center (15.9 kcal/mol) is lower in energy than that for the σ-bond metathesis of dihydrogen to the Rh—C bond (22.7 kcal/mol) and the Rh—O bond (28.4 kcal/mol). The activation barriers of the oxidative addition of subsequent dihydrogen molecules are significantly higher than that of the oxidative addition of the first dihydrogen molecule. These …

The Role Of Confined Hydration And Water Reorganization In Molecular Binding, Joe Z. Wu

Dissertations, Theses, and Capstone Projects

An important factor in guiding the development of drug discovery efforts is the comprehensive assessment of a ligand or drug’s ability to bind its receptor. The metric used to measure this interaction strength is by calculating the binding free energy (BFE). To achieve this accurately, we combine two concepts: (1) Grid Inhomogeneous Solvation Theory (GIST) returns the local water thermodynamic and structural contributions to free energy; and the (2) Alchemical Transfer Method (ATM) obtains the absolute (ABFE) and relative binding free energy (RBFE) estimates between ligand pairs. In this work, we employ Alchemical Water-Transfer to tether bridging water(s) during the …

Studies On The Synthesis, Function, And Properties Of Troponoids, John-Charles A. Baucom

Dissertations, Theses, and Capstone Projects

Troponoids are a unique class of non-benzenoid aromatic compounds with a wide range of demonstrated applications in pharmaceuticals and molecular sensing. The cycloheptatrienone scaffold possesses a noteworthy degree of tunability as a function of ring oxygenation. This manuscript describes our efforts toward a better understanding of the physical consequences of the scaffold to better utilize the motif. Chapter the first discusses our efforts at elucidating the mechanism of troponoid inhibition of the Hepatitis B virus reverse transcriptase RNAse H enzymatic domain. Using homology modeling in conjunction with traditional in vitro assays we were able to establish the likely mechanism of …

Investigating Dna Damage Caused By Reactive Oxygen And Nitrogen Species Via Guided-Ion-Beam Scattering And Computational Techniques, Jonathan Benny

Dissertations, Theses, and Capstone Projects

Among DNA nucleobases, guanine (G) is the primary target for one-electron ionization and oxidation, generating G●+ through various processes, including photooxidation, electrocatalytic oxidation, DNA-binding transition metals, ionizing radiation, and photolysis. This is due to the low adiabatic ionization potential and oxidation potential of guanine. Electron holes from other nucleobases can move to guanine, proving that G●+ production traps oxidative DNA damage. G●+ formation can exacerbate DNA damages and cause secondary reactions from reactive oxygen species (ROS) and reactive nitrogen species (RNS) during pathological processes. The following three projects were conducted using a customized electrospray ionization (ESI) guided-ion-beam tandem mass spectrometer, …

Workshop On Rapid Scan Epr, Gareth R. Eaton, Arthur H. Heiss, Deborah Gale Mitchell, Joshua R. Biller, Richard W. Quine, George A. Rinard, Mark Tseitlin, Sandra S. Eaton

TeachEPR Submissions

An introduction to the method of rapid scan EPR is given with emphasis on the design of rapid scan coils, selection of scan parameters, and the reasons that the method improves signal to noise per unit time.

Understanding Anionic Hyperporphyrins: Tddft Calculations On Peripherally Deprotonated Meso-Tetrakis(4-Hydroxyphenyl)Porphyrin., Jeanet Conradie, Carl C. Wamser, Abhik Ghosh

Chemistry Faculty Publications and Presentations

Presented herein is a DFT/TDDFT study of -tetrakis(4-hydroxyphenyl)porphyrin (H[THPP]) and its Meso-deprotonated tetraanionic form; the latter was modeled as both a free tetraanion and with various counterions. Based on our calculations, the experimentally observed hyperporphyrin spectra are attributed to an admixture of phenol/phenoxide character into the a-type HOMO of tetraphenylporphyrin. The admixture results in an elevation of the orbital energy of the HOMO in relation to other frontier orbitals, which accounts for the observed spectral redshifts. The calculations underscore differences in the performance of different exchange-correlation functionals. Thus, while the popular hybrid functional B3LYP greatly exaggerates the redshift of …

An Effective Secure Multi-Objective Task Scheduling Algorithm In Multi-Cloud Environment, V K S K Sai Vadapalli, Ramesh Babu Gurujukota, Phaneendra Varma Chintalapati, Satyanarayana Murty, G. Sai Chaitanya Kumar, Satish Kumar Kode

Karbala International Journal of Modern Science

In cloud environments, task scheduling is essential for improving performance. Nevertheless, the existence of several heterogeneous clouds makes scheduling extremely difficult, requiring increasingly advanced algorithms to manage these environments' diversity and dynamic nature. To solve this, numerous authors have created a variety of task schedulers utilizing heuristic and metaheuristic techniques. Nevertheless, it remains dynamic and challenging because task scheduling is an NP-hard issue. Furthermore, in many complicated situations, it is still problematic to guarantee security throughout the task’s execution. Therefore, this paper introduces a multi-objective security-aware task scheduler using the Crayfish Mud Ring Optimization Algorithm for a multi-cloud environment. This …

In Memoriam - Nora Sabelli: Master Orchestrator Of Grant Programs And Mentor For Advancing The Interdisciplinary Learning Sciences Field, Eric Hamilton, Jeremy Roschelle, Roy Pea, Barbara Means, Louis Gomez, Kim Gomez, Nancy Butler Songer

Education Division Scholarship

On Friday, September 6, 2024, the learning sciences field lost a giant in Dr. Nora Sabelli, 87 years old, a personal mentor to many researchers and an inspiration to so many learning scientists and STEM leaders. Nora’s first professional career was as a computational chemist, and later she became a passionate leader in research for improving STEM education. Nora’s time as a senior program officer at the National Science Foundation’s (NSF) Education and Human Resources (EHR) directorate was legendary; she was a force of nature who reshaped funding priorities for stronger science and a stronger connection of science to education …

Nanostructured Graphitic Carbon Nitride For Photocatalytic And Electrochemical Applications, Muhammad Abdul Qadeer, Iqra Fareed, Asif Hussaine, Muhammad Asim Farid, Sadia Nazir, Faheem K. Butt, Ji-Jun Zou, Muhammad Tahir, Shang-Feng Du

Journal of Electrochemistry

Graphitic carbon nitride (g-C₃N₄) exhibits great mechanical as well as thermal characteristics, making it a valuable material for use in photoelectric conversion devices, an accelerator for synthesis of organic compounds, an electrolyte for fuel cell applications or power sources, and a hydrogen storage substance and a fluorescence detector. It is fabricated using different methods, and there is a variety of morphologies and nanostructures such as zero to three dimensions that have been designed for different purposes. There are many reports about g-C₃N₄ in recent years, but a comprehensive review which covers nanostructure dimensions …

A Cnt Intercalated Co Porphyrin-Based Metal Organic Framework Catalyst For Oxygen Reduction Reaction, Pei-Pei He, Jin-Hua Shi, Xiao-Yu Li, Ming-Jie Liu, Zhou Fang, Jing He, Zhong-Jian Li, Xin-Sheng Peng, Qing-Gang He

Journal of Electrochemistry

The poor electronic conductivity of metal-organic framework (MOF) materials hinders their direct application in the field of electrocatalysis in fuel cells. Herein, we proposed a strategy of embedding carbon nanotubes (CNTs) during the growth process of MOF crystals, synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure. Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin. Simultaneously, the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency. X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT …

New Insights Into Controlling The Functional Properties Of Tin Oxide-Based Materials, Alexandra Kuriganova, Nina Smirnova

Journal of Electrochemistry

Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for productions of materials with well-defined functional properties. Pulse electrolysis, a top-down electrochemical approach, has been demonstrated to be a viable method for producing nanostructured materials with a particular efficacy in the synthesis of tin oxides. This method allows for significant control over the composition and shape of the resulting tin oxides particles by modifying the anionic composition of the aqueous electrolyte, obviating the need for additional capping agents in the synthesis process and …

Associations Between Social Determinants Of Health And Mental Health Disorders Among U.S. Population: A Cross-Sectional Study, S. Tanarsuwongkul

Faculty Publications

Aims

The impact of social determinants of health (SDOH) on mental health is increasingly realized. A comprehensive study examining the associations of SDOH with mental health disorders has yet to be accomplished. This study evaluated the associations between five domains of SDOH and the SDOH summary score and mental health disorders in the United States.

Methods

We analyzed data from a diverse group of participants enrolled in the All of Us research programme, a research programme to gather data from one million people living in the United States, in a cross-sectional design. The primary exposure was SDOH based on Healthy …

Photolysis And Sublimation Chemistry Of Ammonium Cyanide With Relevance To Cometary Environments, O. H. Wilkins, K. M. Yocum, Vincent J. Esposito, E. Harel, S. N. Milam, P. A. Gerakines

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bulk nitrogen is depleted in solar system objects, including the terrestrial planets, chondritic meteorites, and comets. Recently, it was suggested that cometary nitrogen may be locked up in ammonium salts—ionic solids comprising ammonia (NH₃) and an acid such as hydrogen cyanide (HCN)—based on Rosetta/ROSINA data from comet 67P/Churyumov–Gerasimanko. Among the proposed salts to have been found in 67P were ammonium cyanide (NH₄CN) and ammonium cyanate (NH₄OCN), which were inferred from identifying HCN, cyanamide (NH₂CN), and isocyanic acid (HNCO) in the mass spectrometry data collected in the coma of 67P. However, the relationship …

Tribological, Thermal, Kinetic, And Surface Microtextural Characterization Of Prime P-Type <100> Silicon Wafer Cmp For Direct Wafer Bonding Applications, Michelle Yap, Catherine Yap, Yasa Sampurno, Glenn Whitener, Jason Keleher, Len Borucki, Ara Philipossian

Chemistry Department Faculty Articles

We investigated the tribological, thermal, kinetic, and surface microtextural characteristics of chemical mechanical polishing (CMP) of 300 mm p-type <100> prime silicon wafers (and their native oxide) at various pressures, sliding velocities, and starting platen temperatures. Results showed the dominant tribological mechanism for both native oxide and silicon polishing to be boundary lubrication. Using frictional data, we pinpointed the exact time that corresponded to the total removal of the native oxide and the onset of silicon polishing. This allowed us to separately characterize removal rates of each layer. For native oxide, while the rate depended on temperature, the presence of a …