Volume 84, Issue 10

The IUPAC International Symposium on Ionic Polymerization (IP 2011), was held in Akron, Ohio 10-15 July 2011. We welcomed 165 participants from 18 countries. This was a "homecoming"-the symposium series was initiated by Prof. Joseph P. Kennedy in 1976. This biannual event travelled around the globe, and after 35 years it came back to the University of Akron, the global leader in polymer research. The symposium was co-chaired by Judit E. Puskas from the University of Akron and Robson F. Storey from the University of Southern Mississippi. It started with a mini-symposium honoring the honorary chair, Prof. Kennedy, with international leaders as speakers. The symposium covered a broad range of topics. A unique feature of the symposium was a session devoted to "rising stars" in the field of ionic polymerizations. This volume presents papers based on presentations from that session. We hope to see the rising stars as the next leaders in the field. Judit E. Puskas Conference Co-Chair

The 14th Asian Chemical Congress (14 ACC) was held in Bangkok, Thailand 5-8 September 2011 by the Chemical Society of Thailand (CST) under the patronage of Prof. Dr. Her Royal Highness Princess Chulabhorn. The congress was supported as a tradition hosted by the members of the Federation of Asian Chemical Societies (FACS) and sponsored by IUPAC. The congress was a unique and exciting forum for meeting the challenge put forth by the event's theme: "Contemporary chemistry for sustainability and economic sufficiency". The congress attracted more than 1800 scientists from 48 different countries. Two Nobel Laureate lectures, a Kavli Foundation lecture, 6 plenary lectures, and FACS Award lectures were delivered, and 183 invited papers and approximately 1000 contributed scientific papers were presented in 23 symposia, 45 concurrent sessions, and poster presentations. In order to meet the significance of the theme of the congress and to celebrate the International Year of Chemistry 2011, this issue of Pure and Applied Chemistry collects seven selected articles from invited lectures delivered at the congress to highlight "Sustainability and economic sufficiency: Novelty in green analytical chemistry". These articles are: "Pulsed chronopotentiometric membrane electrodes based on plasticized poly(vinyl chloride) with covalently bound ferrocene functionalities as solid contact transducer" (Eric Bakker); "Laboratory automation based on flow techniques" (Victor Cerda); "Chemiluminescence immunoassay for a nonionic surfactant using a compact disc-type microfluidic platform" (Toshihiko Imato); "Cauliflower polyaniline/multiwalled carbon nanotubes electrode and its applications to hydrogen peroxide and glucose detection" (Proespichaya Kanatharana); "More with less: Advances in flow and paper-based monitoring of nutrients in aquatic systems" (Ian D. McKelvie); "Computer-controlled flow chemical analysis (CC-FCA) and its application to environmental analytical chemistry" (Shoji Motomizu); and "Reagent-free analytical flow methods for the soft drink industry: Efforts for environmentally friendly chemical analysis" (Duangjai Nacapricha). Other general papers presented in the congress were published in the 14 ACC Proceedings. We certainly acknowledge the great contribution made to this congress by the Congress Chair, Prof. Supawan Tantayanont, as well as the local organizing and scientific committees. We also thank the different organizers and session chairs for the symposia and workshops, which were exhibited in a lively manner during this successful congress, and the contributors to this issue. The 15th ACC is scheduled to be held 19-23 August 2013 in Singapore. Supa Hannongbua and Kate Grudpan Conference Editors

This paper highlights the importance of the collection of data that is of suitable quality and of appropriate frequency and/or spatial intensity for the monitoring of aquatic systems. The advantages of automated techniques, such as flow analysis, in monitoring are emphasized, as is the selection of parameters that address the objectives of monitoring. The potential of nascent microfluidic and paper-based analytical techniques as tools for water quality monitoring is examined.

Flow techniques have undoubtedly aroused special interest in relation to many other automatic methodologies of analysis. Ever since segmented flow analysis (SFA) was developed by Skeggs in 1957, flow techniques have been in continuous evolution toward new develop-ments. There is no solid argument in favor of using any particular flow technique separately; rather, substantial advantages can be derived from their combination. Since flow-based methods are nonseparative tools, the advantages of combining flow techniques with separation techniques are noteworthy. High selectivity can be achieved by coupling them with liquid chromatography (LC), gas chromatography (GC), solid-phase extraction (SPE), or capillary electrophoresis (CE). Thus, a detailed description of flow techniques, their evolution, their hyphenation advantages, and a critical comparison between current developed methods exploiting flow techniques aimed at solving present analytical needs are reviewed in this article.

Computer-controlled fluid-flow chemical analysis (CC-FCA) was investigated for the determination of trace amounts of toxic pollutants in the environment. For CC-FCA, automated chemical analysis systems were developed by using computer-controllable pumping and valve modules, and polytetrafluorethylene (PTFE) tubing and connectors. The systems demonstrated in this work were a flow injection-type system, a sequential injection-type system, a mini-column pretreatment system (Auto-Pret system), and an Auto-Pret hyphenated with flow injection analysis (FIA) system. Such systems were fully controlled by a computer program; the lab-made programs were written in Visual Basic. The systems can be hyphenated with some detectors, such as a spectrophotometric detector, an electrochemical detector, electrothermal-atomic absorption spectrometry (ET-AAS), a liquid electrode plasma-atomic emission spectrometry (LEP-AES) and inductively coupled plasma (ICP)-AES. Such systems were successfully applied to the determination of trace amounts of toxic pollutants in environmental water samples: they were heavy metal ions (Pb, Cd, Cr, etc.). In this paper, the author aims mainly at investigating the CC-FCA method for the determination of trace amounts of Cr(VI) in environmental water samples by spectrophotometry. The techniques used in this work were FIA, sequential injection analysis (SIA), and Auto-Pret/FIA, which were all computer-controllable. Limits of detection of Cr(VI) by FIA, SIA, and Auto-Pret/FIA were 8 × 10 –9 mol/L (0.4 μg/L), 1.1 × 10 –8 mol/L (0.6 μg/L), and 1.4 × 10 –9 (0.07 μg/L), respectively. The methods were applied to the determination of Cr(VI) in river and drinking waters.

The evolution of an entirely green analytical system for industrial quality control of carbonated drinks is described. The developed flow system is capable of providing analytical data of the dissolved CO 2 , sucrose, and color of a sample consecutively in real-time. The system has been carefully designed on the basis of “reagent-free”, meaning that no added chemicals are required for the analysis. The system first vaporizes CO 2 from the soft drink in a gas–liquid separation chamber, with a channel for a flow of pure water as the CO 2 acceptor. The dissolved CO 2 alters the conductivity of the water stream, which is directly related to the concentration of CO 2 in the soft drink. The sucrose content is measured based on the “schlieren effect”, the sample plug flows out of the vaporization chamber into a colorimeter with a near-infrared/light-emitting diode (NIR/LED) as light source. The schlieren effect arises at the boundary of pure water and soft drink with refraction of light in proportion to the sugar concentration. The system also measures the absorbance of the sample using an RGB-LED. The related principles and preliminary experiments as proof of concept are described as well as the construction of the flow system for this completely reagent-free analyzer. A simple flow injection system using the schlieren effect was also developed for rapid quantitative analysis of sugar in noncarbonated soft drinks.

A simple and pump-free chemiluminescence immunoassay based on a compact disc (CD)-type microfluidic platform for the determination of alkylphenol polyethoxylates (APnEOs) is described. The method is based on a competitive immunoreaction of the anti-APnEOs antibody immobilized on the magnetic microbeads between APnEOs and horseradish peroxidase (HRP)-labeled APnEOs in the sample solution. The luminol solution containing H 2 O 2 and enhancer is caused to flow from one reservoir in the platform to another by appropriate adjustment of the speed of the rotation of the disc. The detection limit was similar to that reported in our previous paper, i.e., 10 ppb according to IC 80 .

Ion-selective membrane materials based on poly(vinyl chloride) (PVC)-containing covalently attached redox-active ferrocene (Fc) groups are characterized here as all-solid-state pulsed voltammetric ion sensors. The redox capacity of the membrane increases 7-fold with a doubling of the Fc content and 3-fold with the addition of 10 wt % of the lipophilic electrolyte ETH 500, tetradodecylammonium tetrakis(4-chlorophenyl)borate. This salt improves the ionic conductivity of the membrane and appears to make the Fc groups electrochemically more accessible. A too high content of the two, on the other hand, was found to cause undesired sensitivity to redox-active species present in the sample solution. Dilution of the membrane with a plasticizer eliminated this redox sensitivity while preserving its high redox capacity. A practical application of the designed electrodes in electrochemical analysis was demonstrated with a multi-pulse protocol that includes a current-controlled ion uptake pulse, followed by an open-circuit potential (OCP) measurement and a regeneration pulse. Potentiometric calibration curves obtained with this protocol exhibited a linear response with near-Nernstian slopes for acetate, nitrate, chloride, and perchlorate ions with the selectivity expected for an ion-exchanging membrane.

Vertically aligned polyaniline (PANI) structures were prepared by controlling the deposition current density during a stepwise template-free electrochemical deposition process of aniline on a glassy carbon electrode (GCE). Scanning electron micrographs (SEMs) showed the formation of cauliflower PANI structures, each with a diameter of approximately 2–3 and 10 μm in length. The cauliflower-like PANI electrode was modified with multiwalled carbon nanotubes (cauliflower PANI/MWCNTs) and used as the working electrode for electrochemical detections where H 2 O 2 and glucose were used as the models for the chemical sensor and biosensor, respectively. The sensor provided linearity in the range of 1.0 to 150 μM of H 2 O 2 with the limit of detection (LOD) of 50 nM. This is 100-fold better than the LOD of the bare GCE. Moreover, this sensor exhibited remarkable operational stability, i.e., 50 μM H 2 O 2 could be analyzed up to 140 times with a 2.7 % relative standard deviation (RSD). A glucose biosensor was prepared using the modified cauliflower PANI/MWCNT electrode. This had a 3.4 times higher sensitivity than an electrode modified with PANI film/MWCNTs. The regular size and high surface-to-volume ratio of the cauliflower PANI electrode will provide good opportunities for further biosensor applications.

In this paper, more than 70 years of cationic polymerization of isoprene (IP) are reviewed. Up to now, the controlled or living cationic polymerization of IP was never reported due to numerous side reactions, including chain transfer, cyclization, and cross-linking reactions that were very difficult to control. Cationic polyisoprenes (PIPs) are thus described to be mainly 1,4- trans with saturated/cyclized sequences. Although progress was made for their characterization due to many analysis techniques, cationic PIPs are still not yet fully characterized, particularly the saturated sequences. As a consequence, even if suggestions are proposed, polymerization mechanism is still not fully elucidated.

Cationic polymerization of L,L-lactide (LA) in the presence of trifluoromethanesulfonic acid (TfA) has been studied. It was found that propagation proceeds mainly according to the activated monomer (AM) mechanism. Hydroxyl groups required for this type of propagation are formed as a result of the ring opening of protonated lactide. Thus, part of the acid (acting as an initiator) is consumed for the generation of hydroxyl groups, and part (acting as a catalyst) is involved in the protonation of monomer molecules forming secondary oxonium ions which are then able to react with the hydroxyl groups. A dual role of the protic acid is reflected in the kinetic results and in the dependence of experimental degree of polymerization on theoretical values. The structure of active species responsible for polymer chain growth was determined by phosphorus ion-trapping method. The evidence that in the cationic ring-opening polymerization (ROP) of LA initiated by protic acids, both hydroxyl groups and secondary oxonium ions are present throughout the polymerization (as required for polymerization proceeding by the AM mechanism) was found on the basis of changes of the averaged proton chemical shift in 1 H NMR spectra of LA polymerizing mixture.

This review discusses cationic UV-curing processes of vinyl ethers, propenyl ethers, and epoxy monomers. Cationic photopolymerization based on photogeneration of acid from onium salts induced by UV light and consecutive polymerization initiated by photogenerated acid was first proposed at the end of the 1970s. The process engendered high interest both in academia and in industry. Cationic photoinduction presents some advantages over comparable radical-mediated processes, particularly the absence of inhibition by oxygen, low shrinkage, and good adhesion, and mechanical properties of the UV-cured materials. Moreover, the monomers employed are generally less toxic and irritant than acrylates and methacrylates, which are widely used in radical photopolymerization. In this overview, particular emphasis is given to our recent contributions to the field of cationic photopolymerization for different classes of monomers.

A series of polyethers was prepared by monomer-activated anionic polymerization. The combination of an ammonium salt with triisobutylaluminum allowed the polymerization of epoxides containing various aliphatic side chains (1,2-butene oxide (BO), 1,2-hexene oxide (HO), and 1,2-octadecene oxide (ODO)) or a fluorinated group (3,3,3-trifluoro-1,2-epoxypropane (TFEP)). Polymers of molar masses up to 35 000 g/mol with relatively narrow molar mass distribution could be synthesized. Polymer structures were analyzed by 13 C NMR, and the thermal behavior was studied by differential scanning calorimetry (DSC). The evolution of hydrophobicity was investigated according to the length and composition of the side chain. Using a long aliphatic side-chain epoxide (C16) imparted crystallinity to the resulting atactic polymer.

Neutral Ni II complexes, classically used for catalytic ethylene polymerization, can play an additional role as radical initiators of the homo- and copolymerizations of (meth)acrylates and styrene. Benefiting from this duality, the copolymerization of ethylene and various (meth)acrylates or styrene was successfully performed. Multiblock copolymers containing sequences of both ethylene and (meth)acrylates were prepared for the first time from an original dual radical/catalytic mechanism.

Reduction sensitivity and mild synthetic conditions make disulfide-bonded materials ideal for degradable biomaterial applications. Both the degradation and the synthetic advantages of disulfide-bonded biomaterials have been applied to drug delivery vesicles, protein conjugation, and hydrogel biomaterials, but the synthetic advantages are rarely seen in the creation of biopolymers. A greener and highly efficient oxidative system is presented for the polymerization dithiols to high-molecular-weight poly(disulfide) polymers. The application of this system to 2-[2-(2-sulfanylethoxy)ethoxy]ethanethiol (DODT) produced corresponding degradable poly(disulfide) polymers with molecular weights as high as M n = 250 000 g/mol and with a polydispersity index (PDI) as low as 1.15.

This document provides (i) definitions of terms related to macromolecular rotaxanes and macromolecular pseudorotaxanes and (ii) recommendations for naming these macromolecular assemblies. The nomenclature recommendations presented here have been developed by combining the nomenclature rules for the low-molar-mass (low-M) rotaxanes and those for macromolecules (both established in published IUPAC recommendations) in such a way that the developed nomenclature system provides unambiguous names for macromolecular rotaxanes (and pseudorotaxanes), including differentiation among various isomers of these supramolecular assemblies. Application of the nomenclature recommendations is illustrated using examples covering a wide range of structure types of macromolecular rotaxanes and pseudorotaxanes. An Alphabetical Index of Terms and a List of Abbreviations and Prefixes are included.

The universal adoption of an agreed nomenclature has never been more important for the description of chemical structures in publishing and online searching. The International Union of Pure and Applied Chemistry (IUPAC) and Chemical Abstracts Service (CAS) make similar recommendations. The main points are shown here with references to original documents. Further details can be found in the IUPAC Purple Book.

Circular dichroism (CD) spectroscopy is a widely used technique for the characterisation of proteins. A number of CD instruments are currently on the market, and there are more than a dozen synchrotron radiation circular dichroism (SRCD) beamlines in operation worldwide. All produce different output formats and contents. In order for users of CD and SRCD data to be able simply to compare and contrast data and the associated recorded or unrecorded metadata, it is essential to have a common data format. For this reason, the JCAMP-DX-CD format for CD spectroscopy has been developed, based on extensive consultations with users and senior representatives of all the instrument manufacturers and beamlines, and under the auspices of IUPAC, based on the Joint Committee on Atomic and Physical Data Exchange protocols. The availability of a common format is also important for deposition to, and access from, the Protein Circular Dichroism Data Bank, the public repository for CD and SRCD data and metadata. The JCAMP-DX-CD format can be read by standard JCAMP programs such as JSpecView. We have also created a series of parsers, available at the DichroJCAMP web site (http://valispec.cryst.bbk.ac.uk/formatConverter/dichroJCAMPDX-CD.html), which will enable the conversion between instrument and beamline formats and the JCAMP-DX-CD format.