Category: News

A New Biomimetic Approach to Superhydrophobic Nanocomposite Coating Materials Inspired by Natural Materials (Lotus Leaf and Duck Feather)

Soha M. Albukhari (Advisor: Dr. Patricia Heiden)

Doctoral Student, Department of Chemistry, Michigan Technological University

November  17, 2014 – 8:30 am – Fisher Hall, Room 126

Abstract:

This proposal describes a novel approach to create of superhydrophobic polymeric nanocoating materials, inspired by the water-repellant properties in two natural materials, lotus leaves and duck feathers. The process combines simple synthetic techniques with coaxial electrospinning and ultrasonication techniques to form a novel, reinforced superhydrophobic and self-cleaning coating on a glass substrate. To accomplish this we prepare a PMMA-grafted graphene suspension and a fluorinated silica nanoparticle suspension. These two fluids were used in coaxial electrospinning to produce a novel core-sheath nanofiber coating material with a dual superhydrophobic structure that mimics the critical structures in duck feathers and lotus leaves. These features are expected to give nanocomposite micro-nano core-sheath fibers that will impart superhydrophobic properties by increasing the water contact angle (CA) to more than 150º, and give a self-cleaning surface by having a water roll-off angle of less than 10º. These values are also expected to make the surface resistant to icing. Such a dual biomimetic structure has never been produced before, and by combining these features we will be able to study how these two differently functioning structures interact. The basic purpose of the PMMA-graphene core is to fill the air space in the micro-nano helix of the core-sheath nanocomposite by forming a cushion on the fiber-water interface, decreasing its surface wettability. Moreover, graphene electro-conductivity provides anti-icing properties and adds mechanical strength to the coating, so if the sheath layer fails, the graphene layer will still function independently. Studying this new dual-mimetic material may reveal new information about morphology and nanostructures that impart superhydrophobicity, which has value for coating applications such as airplane wings, sidewalks, car windshields, runways, and roads.


Title: Applications of Quantum Chemical Methods to Atmospheric Reactions

Dr. Heather A. Rypkema

Department of Atmospheric, Oceanic, and Space Sciences

University of Michigan

November 14, 2014  

3:00 pm Chemical Sciences Building~ Room 101

Abstract:

Quantum chemical methods have a broad-ranging capacity toward informing our understanding of molecular transformations in a variety of environments, including the chemistry of the atmosphere. Specifically, these applications include kinetic and thermodynamic analysis of chemical reactions, evaluation of competing reaction channels, and the theoretical validation of postulated chemical mechanisms. This presentation provides a survey quantum chemistry as applied to a number of atmospherically relevant studies. The full atmospheric oxidation profile of peroxyacetic acid predicts the likely fate of a prevalent atmospheric species while postulating a new source of reactive species not represented in current models. The direct and catalyzed hydration of formic acid and acetaldehyde provide a mechanism for the formation of hygroscopic molecules capable of initiating cloud formation and the production of SOA. Diabatic excited states can be used to predict the relative reactivity among atom-transfer reactions, which are particularly significant in a hydroxyl-rich environment. A mechanism for the proliferation of atmospheric hydroxyl radical through the atmospheric oxidation of cyclical alkanes provides a possible explanation for the discrepancy between predicted and measured OH levels in the troposphere. Cumulatively, these studies will demonstrate the diverse applications of theoretical quantum chemistry in enhancing our understanding of atmospheric chemistry.


Elucidating the Pathways for Protein Misfolding and Aggregation: Unity in Diversity.

Dr. Ashutosh Tiwari, Assistant Professor of Chemistry

Department of Chemistry,  Michigan Technological University     

November 7, 2014  ~  3:00pm  ~  Chemical Science Building, Room 101

Abstract:

Due to the aging of baby boomers in the USA, the proportion of the population in higher age groups has increased. This demographic shift coupled with a concomitant increase in longevity has brought new challenges and threats in the form of diseases and disorders that not only affect an individual but impact the whole society at large. Increased oxidative damage of proteins associated with aging causes them to misfold and aggregate and thus, disorders related to protein misfolding and aggregation are on the rise. Since many aggregated proteins share a common fibrillar structure at the molecular level, understanding the principles and contributing factors that regulate protein misfolding, surface hydrophobic exposure, aberrant interactions, or aggregation is key to understanding their relationship to cellular toxicity. I will discuss recent results from my laboratory wherein we studied several proteins for their surface-hydrophobic exposure and aggregation propensity at physiological pH and temperature. Identifying shared protein aggregation pathways for a large set of structurally diverse proteins will lead to a better understanding of the disease process and as a consequence provide common effective targets for therapy.


Green Chemistry: An Overview of Principles and Applications

Mark R. Mason

Professor, Department of Chemistry and Biochemistry and
Director,  School of Green Chemistry and Engineering
The University of Toledo
Thursday, November 6, 2014
11:00 am Chemical Sciences Building Room 102

Over the past two decades, there has been a dramatic shift in the way government and industry view pollution prevention and the environmental consequences of chemical manufacture in the United States. Source reduction, rather than “end of the pipe” waste treatment, is now the preferred method for reducing pollution. This approach requires chemists and engineers to be increasingly aware of the environmental consequences of the chemical-related products and processes we develop. Green chemistry, “the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances,” is the foundation of this increased awareness. This presentation will provide an overview of selected green chemistry principles, green chemistry applications and metrics, chemical alternatives assessment, and future opportunities.


American Chemical Society Meeting

The fall 2014 meeting of the American Chemical Society—Upper Peninsula Local Section will be held Friday October 24, 2014 at 4 p.m. in Chem Sci 101.

Sarah Green (Chem) will be the featured presenter. Green recently returned from a yearlong experience in Washington (DC) where she served as the Jefferson Science Fellow. Refreshments will be provided.


DNA as a Catalyst

Prof. Scott K. Silverman,   Professor of Chemistry

Department of Chemistry, University of Illinois at Urbana-Champaign

October 10, 2014  ~  3:00pm  ~    Chemical Science Building, Room 101

Abstract:

DNA in its double-stranded form is familiar as the genetic material. When single-stranded, however, DNA can adopt complex three-dimensional structures that allow binding of substrates and catalysis of chemical reactions. DNA has many conceptual and practical advantages over other biologically derived polymers (proteins and RNA) for applications as a catalyst.  This presentation describes the development of DNA catalysts, or deoxyribozymes, for a variety of chemical reactions, primarily involving covalent modification of peptide and protein substrates.


Mineralogical Miracles at Merelani, Tanzania

John A. Jaszczak
Department of Physics and the A. E. Seaman Mineral Museum Michigan Technological University

 December 5,  2014, 3:00pm Chemical Science Building, Room 101

Abstract:

The Lelatema Mountains in northern Tanzania are host to one of the world’s richest flake graphite deposits, but it is the purple-blue gem variety of zoisite called “tanzanite” that has brought renown to the region since the 1960s.

In December 2007 a pocket of exceptionally fine crystals of graphite was discovered at in Merelani’s Block D. Given graphite’s extreme softness and obvious lack of gem value, it seems almost in miraculous that specimens of these graphite crystals, perhaps the finest in the world, were superbly preserved. Adding to their uniqueness and beauty, the graphite crystals are covered by a secondary overgrowth of graphite that contains rare stellate graphite dendrites. The pocket also produced superb gem-quality crystals of diopside, fluorapatite, and tremolite crystals. More recently, world-class specimens of several sulfide minerals have been discovered and preserved. These include highly lustrous, large Pyrite crystals, exceptionally large, translucent crystals of the rare ZnS polytype wurtzite, and rare black octahedral crystals of alabandite. This illustrated lecture will briefly tour this amazing mining district, review these seemingly miraculous mineralogical that have been uncovered.


Kiteplatin: A Rediscovered Antitumor Drug

Dr. Emanuele Petruzzella
epetruzz@emich.edu
Postdoctoral Researcher Scholar, Chemistry Department, Eastern Michigan University
09/26/2014 – 3:00 pm – Room 101, Chemical Sciences and Engineering Bldg

Abstract:

The antitumor activity of kiteplatin was reported for the first time twenty years ago. Recently, kiteplatin was investigated as potential antitumor drugs for the treatment of cisplatin- and oxaliplatin-resistant tumors.

Resistance to Pt-based antitumor drugs can involve different processes, such as the binding of S-donor biomolecules, like glutathione, cysteine and methionine, to the Pt metal center. This interaction prevents Pt drugs to react with DNA, i.e. the event triggering the antitumor effect. Kiteplatin showed an unique reactivity with these S-donors biomolecules and, for the first time, it was found that, also after reaction with glutathione, kiteplatin is still able to react with a DNA model. This unique behaviour could explain the activity of kiteplatin in cisplatin- and oxaliplatin-resistant tumors.

In recent years, several research groups investigated Pt(IV) derivatives of Pt-based anticancer drugs as pro-drugs for oral administration. The axial dihydroxido Pt(IV) derivative of kiteplatin undergoes a spontaneous thermal- and/or photoinduced reduction process. This Pt(IV) complex can be suitable for photo-therapy.


Dow Corporate Venturing-Accelerating Dow’s Innovation Agenda

Mr. Stephen Hahn, Research Fellow

Dow Corporate Venturing
09/25/2014 – 1:00 pm – Room 101, Chemical Sciences and Engineering Bldg
Abstract:

Dow Corporate Venturing (DCV) serves to identify new technologies for Dow, to analyze and quantify new market opportunities enabled by these breakthroughs, and to capture their value by commercializing or participating in them. DCV serves as an innovation pipeline for Dow, supplying a continuous flow of new business options for the company. The Technology Scouting group within DCV seeks to identify and interact with emerging technology-based companies, and to connect directly with the sources of these innovations, with a focus on developing strategic relationships. Dow Technology Scouting group has established region-specific networks, enabling a global approach to innovation sourcing that meshes with the development and innovation targets of the Corporation, and encourages a Company-wide scouting mentality. Technology Scouting is Dow’s front line for identification and assessment of new opportunities and our Technology Scouts provide a conduit for innovation from the external marketplace of technology into Dow. Examples of recently analyzed, external, technology-based companies will be discussed.


Molecular characterization of atmospheric organic matter in biogenic secondary organic aerosol, ambient aerosol and clouds

Chemistry Seminar
Tuesday, September 23, 2014
EERC 314

Molecular characterization of atmospheric organic matter in biogenic secondary organic aerosol, ambient aerosol and clouds

Ms Yunzhu Zhao
(Advisor: Dr. Lynn Mazzoleni)
Doctoral Candidate
Department of Chemistry
Michigan Technological University

ABSTRACT

Atmospheric aerosol affects the Earth’s energy budget, reduces visibility and influences human health. The organic composition of aerosol is quite complex and continuously evolves through various atmospheric processes. To gain a deeper understanding of the molecular composition of atmospheric organic matter (AOM), chamber-generated biogenic secondary organic aerosol (SOA), ambient aerosol and cloud water samples were studied. Ultrahigh resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry was used to provide detailed molecular characterization of the atmospheric samples. Due to the extremely high mass resolution and mass accuracy, thousands of individual molecular formulas were identified in all of the samples studied. Multivariate statistical analysis methods were evaluated to compare the similarities and differences of the sample compositions. The molecular characterization of biogenic SOA, ambient aerosol and clouds will be discussed. This study of the three types of atmospheric samples helps to understand the composition of AOM with respect to atmospheric processes.