Ozone Cracking in Drafting Aprons
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Functional Group Composition of Secondary Organic Aerosol Formed from Ozonolysis of A-Pinene Under High VOC and Autoxidation
Article Cite This: ACS Earth Space Chem. 2018, 2, 1196−1210 http://pubs.acs.org/journal/aesccq Functional Group Composition of Secondary Organic Aerosol Formed from Ozonolysis of α‑Pinene Under High VOC and Autoxidation Conditions Megan S. Claflin,†,‡ Jordan E. Krechmer,†,‡,§ Weiwei Hu,†,‡,∥ Jose L. Jimenez,†,‡ and Paul J. Ziemann*,†,‡ †Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, Colorado 80309, United States ‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States *S Supporting Information ABSTRACT: The formation of secondary organic aerosol (SOA) from α-pinene ozonolysis has been widely studied, with a recent focus on contributions from highly oxidized multifunctional compounds (HOMs) that have been observed in laboratory and field studies. Most of what is known about the chemical composition of SOA and HOMs, however, consists of molecular formulas and limited molecular structure identification based on mass spectrometric analysis. Here, we characterized the SOA formed from α-pinene ozonolysis using derivatization-spectrophotometric methods to quantify per- oxide, carbonyl, carboxyl, ester, and hydroxyl groups. Experiments were conducted over a range of α-pinene concentrations and relative humidities, including regimes in − which gas-phase HOMs were detected using NO3 chemical ionization mass spectrometry. Results for experiments conducted with high concentrations of α-pinene were also compared with predictions of a model that employed the Master Chemical Mechanism and included gas-particle and gas-wall partitioning. It appears that gas-phase monomer and dimer products formed • • • • through RO2 +RO2 ,RO2 +HO2,RO2 isomerization, and stabilized Criegee intermediate + carboxylic acid or water reactions contributed to SOA formation, but that in particles the aldehyde and ketone groups in these compounds were often converted to carboxyl and ester groups through Baeyer−Villiger reactions with hydroperoxides and peroxycarboxylic acids. -
The Reactions of Alkenes
The Reactions of Alkenes The Stereochemistry of Addition Reactions 1 Diverse Reactions of Alkenes Alkenes react with many electrophiles to give useful products by addition (often through special reagents) 2 Preparation of Alkenes: A Preview of Elimination Reactions • Alkenes are commonly made by – elimination of HX from alkyl halide (dehydrohalogenation) • Uses heat and KOH – elimination of H-OH from an alcohol (dehydration) • requires strong acids (sulfuric acid, 50 ºC) 3 A Regioselective Reaction A reaction in which one structural isomer is favored over another, leading to its predominance in the mixture of products. 4 A Stereoselective Reaction A reaction in which one stereoisomer in a mixture is produced more rapidly than another, resulting in predominance of the favored stereoisomer in the mixture of products. 5 A Stereospecific Reaction A reaction in which a particular stereoisomeric form of reactant gives one specific stereoisomer of product, while a different stereoisomeric form of reactant leads to a different single pure streoisomer of product. Stereospecific reaction is also stereoselective; however, stereoselective reaction is not stereospecific. 6 An Electrophilic Addition Reaction where HX = HF, HCl, HBr, and HI Reactivity of HF << HCl < HBr < HI since HF is less acidic and HI is most acidic. The rate of addition of HI is too fast to measure. 7 The Mechanism of the Reaction 8 Relative Stabilities of Carbocations 9 Hyperconjugation Stabilizes a Carbocation 10 The Difference in Carbocation Stability Determines the Products -
Carboxylic Acids from Limonene Oxidation by Ozone and Hydroxyl Radicals: Insights Into Mechanisms Derived Using a FIGAERO-CIMS
Atmos. Chem. Phys., 19, 13037–13052, 2019 https://doi.org/10.5194/acp-19-13037-2019 © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License. Carboxylic acids from limonene oxidation by ozone and hydroxyl radicals: insights into mechanisms derived using a FIGAERO-CIMS Julia Hammes1, Anna Lutz1, Thomas Mentel1,2, Cameron Faxon1, and Mattias Hallquist1 1Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden 2Institute of Energy and Climate Research, Troposphere (IEK-8), Forschungszentrum Jülich GmbH, Jülich, Germany Correspondence: Mattias Hallquist ([email protected]) Received: 21 September 2018 – Discussion started: 27 September 2018 Revised: 10 July 2019 – Accepted: 25 July 2019 – Published: 22 October 2019 Abstract. This work presents the results from a flow reactor are suggested to fill-in the knowledge gaps. Using the addi- study on the formation of carboxylic acids from limonene tional mechanisms proposed in this work, nearly 75 % of the oxidation in the presence of ozone under NOx-free condi- observed gas-phase signal in our lowest concentration exper- tions in the dark. A High-Resolution Time-of-Flight acetate iment (8.4 ppb converted, ca. 23 % acid yield) carried out un- Chemical Ionisation Mass Spectrometer (HR-ToF-CIMS) der humid conditions can be understood. was used in combination with a Filter Inlet for Gases and AEROsols (FIGAERO) to measure the carboxylic acids in the gas and particle phases. The results revealed that limonene oxidation produced large amounts of carboxylic 1 Introduction acids which are important contributors to secondary organic aerosol (SOA) formation. The highest 10 acids contributed Atmospheric aerosol particles have an impact on climate and 56 %–91 % to the total gas-phase signal, and the domi- human health, and their respective effects depend on par- nant gas-phase species in most experiments were C8H12O4, ticle properties determined by the particle size and chem- C9H14O4,C7H10O4 and C10H16O3. -
Bioinspired Surfaces Adapted from Lotus Leaves for Superliquiphobic Properties DISSERTATION Presented in Partial Fulfillment Of
Bioinspired Surfaces Adapted from Lotus Leaves for Superliquiphobic Properties DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Samuel Graeme Martin, M.S. Graduate Program in Mechanical Engineering The Ohio State University 2017 Dissertation Committee: Professor Noriko Katsube, Advisor Professor Anthony Luscher Professor Shaurya Prakash Copyrighted by Samuel Graeme Martin 2017 Abstract Nature can be turned to for inspiration into novel engineering designs that help address scientific difficulties. Through evolution, nature has created efficient and multipurpose objects using commonly occurring materials. These objects have many applications that can aid humanity and can be of commercial interest. One technical difficulty that nature can help solve includes liquid repellency. Inspiration for extreme liquid repellency, also known as superliquiphobicity, can be found on lotus leaves (Nelumbo nucifera) due to their extreme water repellency. The motivation for studying the surface of lotus leaves is that their unique surface features can be adapted for commercial applications to save time, money, and lives. Nature has a limited material toolbox, but by incorporating synthetic materials and better manufacturing processes, the surface properties can be enhanced. Mimicking these biological structures and using them for design inspirations is the field of biomimetics. In this thesis, an introduction chapter on biomimetics and liquid repellency is first presented. These principles are referred to throughout the thesis for creating superliquiphobic surfaces. Next, a chapter on experimental procedure and sample characterization is presented. Afterwards, three chapters are presented containing original research on surfaces inspired by lotus leaves for liquid repellency. -
I. an Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Student Research Projects, Dissertations, and Theses - Chemistry Department Chemistry, Department of 2011 I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials. Charles Edward Schiaffo University of Nebraska-Lincoln Follow this and additional works at: https://digitalcommons.unl.edu/chemistrydiss Part of the Organic Chemistry Commons Schiaffo, Charles Edward, "I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials." (2011). Student Research Projects, Dissertations, and Theses - Chemistry Department. 23. https://digitalcommons.unl.edu/chemistrydiss/23 This Article is brought to you for free and open access by the Chemistry, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Student Research Projects, Dissertations, and Theses - Chemistry Department by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials. By Charles E. Schiaffo A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy Major: Chemistry Under the Supervision of Professor Patrick H. Dussault Lincoln, Nebraska June, 2011 I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials. Charles E. Schiaffo, Ph.D. University of Nebraska-Lincoln, 2011 Advisor: Patrick H. Dussault The use of ozone for the transformation of alkenes to carbonyls has been well established. The reaction of ozone with alkenes in this fashion generates either a 1,2,4- trioxolane (ozonide) or a hydroperoxyacetal, either of which must undergo a separate reduction step to provide the desired carbonyl compound. -
Intensified Ozonolysis of Lignins in a Spray Reactor: Insights Into Product Yields and Lignin Structure
Reaction Chemistry & Engineering Intensified Ozonolysis of Lignins in a Spray Reactor: Insights into Product Yields and Lignin Structure Journal: Reaction Chemistry & Engineering Manuscript ID RE-ART-03-2019-000098.R1 Article Type: Paper Date Submitted by the 20-Apr-2019 Author: Complete List of Authors: Silverman, Julian; University of Kansas, Center for Environmentally Beneficial Catalysis Danby, Andrew; Unviersity of Kansas, Center for Environmentally Beneficial Catalysis Subramaniam, Bala; University of Kansas, Center for Environmentally Beneficial Catalysis Page 1 of 23 Reaction Chemistry & Engineering 1 Intensified Ozonolysis of Lignins in a Spray Reactor: 2 Insights into Product Yields and Lignin Structure 3 Julian R. Silverman1, Andrew M. Danby1, Bala Subramaniam1,2* 4 5 1Center for Environmentally Beneficial Catalysis, University of Kansas, 1501 Wakarusa Drive, 6 Lawrence, Kansas 66047, United States 7 8 2Department of Chemical and Petroleum Engineering, University of Kansas, 1530 W. 15th Street, 9 Lawrence, Kansas 66045, United States 10 11 *Corresponding Author: [email protected]. Tel.: +1-785-864-2903. Fax: +1-785-864-6051 12 13 Abstract 14 We demonstrate a simple spray reactor for an ozonolysis pretreatment step to cleave carbon- 15 carbon double bonds in grass lignins to conveniently recover vanillin and p-hydroxybenzaldehyde 16 (~5 wt. % of the lignin), two of the most value-added monomers. Lignin dissolved in an acid 17 solution is sprayed into an ozone containing gas stream at ambient temperatures with contact 18 times of less than 10 seconds. The production rate of these valuable species is between one to 19 two orders of magnitude greater than that previously reported in a CSTR in which ozone is 20 bubbled through a liquid phase containing dissolved lignin. -
20 More About Oxidation–Reduction Reactions
More About 20 Oxidation–Reduction Reactions OOC n important group of organic reactions consists of those that O A involve the transfer of electrons C from one molecule to another. Organic chemists H OH use these reactions—called oxidation–reduction reactions or redox reactions—to synthesize a large O variety of compounds. Redox reactions are also important C in biological systems because many of these reactions produce HH energy. You have seen a number of oxidation and reduction reactions in other chapters, but discussing them as a group will give you the opportunity to CH3OH compare them. In an oxidation–reduction reaction, one compound loses electrons and one com- pound gains electrons. The compound that loses electrons is oxidized, and the one that gains electrons is reduced. One way to remember the difference between oxidation and reduction is with the phrase “LEO the lion says GER”: Loss of Electrons is Oxi- dation; Gain of Electrons is Reduction. The following is an example of an oxidation–reduction reaction involving inorganic reagents: Cu+ + Fe3+ ¡ Cu2+ + Fe2+ In this reaction,Cu+ loses an electron, so Cu+ is oxidized. Fe3+ gains an electron, so Fe3+ is reduced. The reaction demonstrates two important points about oxidation– reduction reactions. First, oxidation is always coupled with reduction. In other words, a compound cannot gain electrons (be reduced) unless another compound in the reaction simultaneously loses electrons (is oxidized). Second, the compound that is oxidized (Cu+) is called the reducing agent because it loses the electrons that are used to reduce the other compound (Fe3+). Similarly, the compound that is reduced (Fe3+) is called the oxidizing agent because it gains the electrons given up by the other compound (Cu+) when it is oxidized. -
Mechanical Properties of Rubber
8434_Harris_33_b.qxd 09/20/2001 12:30 PM Page 33.1 CHAPTER 33 MECHANICAL PROPERTIES OF RUBBER Ronald J. Schaefer INTRODUCTION Rubber is a unique material that is both elastic and viscous. Rubber parts can there- fore function as shock and vibration isolators and/or as dampers.Although the term rubber is used rather loosely, it usually refers to the compounded and vulcanized material. In the raw state it is referred to as an elastomer. Vulcanization forms chem- ical bonds between adjacent elastomer chains and subsequently imparts dimen- sional stability, strength, and resilience. An unvulcanized rubber lacks structural integrity and will “flow” over a period of time. Rubber has a low modulus of elasticity and is capable of sustaining a deformation of as much as 1000 percent. After such deformation, it quickly and forcibly retracts to its original dimensions. It is resilient and yet exhibits internal damping. Rubber can be processed into a variety of shapes and can be adhered to metal inserts or mounting plates. It can be compounded to have widely varying properties.The load- deflection curve can be altered by changing its shape. Rubber will not corrode and normally requires no lubrication. This chapter provides a summary of rubber compounding and describes the static and dynamic properties of rubber which are of importance in shock and vibration isolation applications. It also discusses how these properties are influenced by envi- ronmental conditions. RUBBER COMPOUNDING Typical rubber compound formulations consist of 10 or more ingredients that are added to improve physical properties, affect vulcanization, prevent long-term dete- rioration, and improve processability.These ingredients are given in amounts based on a total of 100 parts of the rubber (parts per hundred of rubber). -
Organic Chemistry I: Reactions and Overview
Organic Chemistry I: Reactions and Overview Andrew Rosen Editor: Raghav Malik January 13, 2013 Contents I Library of Synthetic Reactions 3 II Organic Trends and Essentials 4 1 The Basics: Bonding and Molecular Structure 4 1.1 Resonance Stability . 4 2 Families of Carbon Compounds 4 2.1 Strength of London Dispersion Forces (Polarizability) . 4 2.2 Degree of Unsaturation . 4 3 An Introduction to Organic Reactions and Their Mechanisms 4 3.1 Comparing Acid Strengths . 4 4 Nomenclature and Conformations of Alkanes and Cycloalkanes 5 4.1 Ring Flipping . 5 5 Stereochemistry 5 5.1 Naming Enantiomers via the -R and -S System . 5 5.2 Stereochemistry Examples . 6 6 Ionic Reactions - Overview 6 6.1 General Nucleophilic Substitution Reactions . 6 6.2 Carbocation Stability . 6 6.3 Factors Aecting the Rates of SN 1 and SN 2 Reactions . 6 6.4 Elimination Reactions . 7 6.5 Summary . 7 7 Alkenes and Alkynes I - Overview 8 7.1 The E-Z System . 8 7.2 Relative Stabilities of Alkenes . 8 7.3 Factors Aecting Elimination Reactions . 8 7.4 Acid-Catalyzed Dehydration of Alcohols . 8 1 III Reaction Mechanisms 9 8 Ionic Reactions - Mechanisms 9 8.1 The SN 2 Reaction . 9 8.2 The SN 1 Reaction . 10 8.3 The E2 Reaction . 10 8.4 The E1 Reaction . 11 9 Alkenes and Alkynes I - Mechanisms 11 9.1 Acid-Catalyzed Dehydration of Secondary or Tertiary Alcohols: An E1 Reaction . 11 9.2 Acid-Catalyzed Dehydration of Primary Alcohols: An E2 Reaction . 12 9.3 Synthesis of Alkynes from Vic-Dihalides . -
Ozone Resistance of Neoprene Rubber Sheet by Neoprene Rubber Sheet - [email protected], Date: Dec.10.06
Ozone resistance of neoprene rubber sheet By Neoprene Rubber Sheet - www.dongrubber.com, [email protected], Date: Dec.10.06 Neoprene rubber sheet is a polymer of good ozone resistance. According to the ozone resistance, elastomers can be divided into three categories: ① The elastomer itself has ozone resistance, which has no double bond or less double bonds saturated elastomer. Such as EPDM rubber, chlorosulfonated polyethylene, chlorinated polyethylene rubber and silicone rubber, etc. ② The elastomer which itself has good ozone resistance, and with the help of a formula can be obtained better ozone resistance, such as butyl rubber, neoprene rubber and so on. ③ The elastomer itself has poor ozone resistance, must cooperate with ozone resistance antiager, such as natural rubber, styrene butadiene rubber, butadiene rubber and butyl rubber, etc. Diene elastomer basically belongs to the third class, and why butyl rubber and neoprene rubber are listed in good ozone resistance of the second class? This is due to the low unsaturation of butyl rubber, similar to the low unsaturation elastomer with good ozone resistance. About neoprene rubber we can make the following instructions: olefins compounds after the double bond parts subjected to ozone, ozone compound generated, the ozonide is unstable, easy to crack, so as to cut the carbon-carbon main chain, namely the so-called "ozone cracking". This reaction can be interpreted as a double bond part with characteristics of nucleophilic carbon atoms react with oxygen atoms with characteristics of electrophilic in the ozone, and formed the ozonide. The nucleophilic properties of carbon atoms depend on the substituent of the molecule is easy to attract electrons or easy to emit electrons. -
Degradable Plastics Are Vulnerable to Cracks
Journal Pre-proofs Degradable plastics are vulnerable to cracks Xuxu Yang, Jason Steck, Jiawei Yang, Yecheng Wang, Zhigang Suo PII: S2095-8099(21)00148-X DOI: https://doi.org/10.1016/j.eng.2021.02.009 Reference: ENG 661 To appear in: Engineering Received Date: 30 August 2020 Revised Date: 13 January 2021 Accepted Date: 8 February 2021 Please cite this article as: X. Yang, J. Steck, J. Yang, Y. Wang, Z. Suo, Degradable plastics are vulnerable to cracks, Engineering (2021), doi: https://doi.org/10.1016/j.eng.2021.02.009 This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The Authors Engineering 7 (2021) Research Green Chemical Engineering: Soft Materials—Letter Degradable Plastics Are Vulnerable to Cracks Xuxu Yang a,b, Jason Steck a, Jiawei Yang a, Yecheng Wang a, Zhigang Suo a,* a John A. Paulson School of Engineering and Applied Sciences, Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, MA 02138, USA b State Key Laboratory of Fluid Power and Mechatronic System, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Department of Engineering Mechanics and Center for X-Mechanics, Zhejiang University, Hangzhou 310027, China * Corresponding author. -
Reactions of Alcohols
Reactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations – the majority of which are either oxidation or reduction type reactions. Normally: Oxidation is a loss of electrons; Reduction is a gain of electrons. But in organic terms: Oxidation: loss of H2; addition of O or O2; addition of X2 (halogens). Reduction: - addition of H2 or H ; loss of O or O2; loss of X2. Neither an oxidation nor reduction: Addition or loss of H+, H2O, HX. Ch11 Reacns of Alcohols (landscape).docx Page 1 Oxidation of Alcohols Primary and secondary alcohols are easily oxidized by a variety of reagents. Secondary Alcohols The most common reagent used for oxidation of secondary alcohols to ketones is chromic acid, H2CrO4. Chromic acid is produced in situ by reaction of sodium dichromate, sulfuric acid and water. Na2Cr2O7 + H2O + 2H2SO4 2 H2CrO4 + 2 NaHSO4 Ch11 Reacns of Alcohols (landscape).docx Page 2 Mechanism of oxidation The alcohol and chromic acid produce a chromate ester, which then reductively eliminates the Cr species. The Cr is reduced (VI IV), the alcohol is oxidized. Oxidation of Primary Alcohols Primary alcohols are easily oxidized just like secondary alcohols, and the INITIAL product of oxidation is an aldehyde. Ch11 Reacns of Alcohols (landscape).docx Page 3 However, the aldehyde can also be easily oxidized to an acid, and this ‘over-oxidation’ is a practical problem. E.g. A common reagent that selectively oxidizes a primary alcohol to an aldehyde (and no further) is pyridinium chlorochromate, PCC. N: CrO3, HCl (PCC) E.g. Tertiary Alcohols These are resistant to oxidation because they have no hydrogen atoms attached to the oxygen bearing carbon (carbinol carbon).