Electrochemical Sensing of Dopamine using a Dodecylsulfate Doped Polypyrrole Film

A polymer-modified electrode was fabricated by the electropolymerisation of pyrrole from an ethanol solution using sodium dodecylsulfate as a dopant. The modified electrode is a highly sensitive electrochemical sensor for dopamine with a limit of detection measured as 3.8 x 10-8 mol dm-3. The sensor did not sense the common interferant ascorbic acid showing a single redox peak for dopamine in the presence of excess ascorbic acid

CSI in a Lab: A Problem Solving Approach to Undergraduate Chemistry Practicals

With an ever demanding job market and industry complaints of grade inflation in the university sector, our graduates need more than just good grades to obtain successful employment. They need to be able to demonstrate a wide variety of skills such as problem solving, team work and the ability to work on their own initiative. This paper discusses a new type of chemistry practical that tries to incorporate all of these skills into an engaging undergraduate laboratory entitled “Mystery Death on a River”. Chemistry undergraduate labs at present often follow the cookbook recipe approach where students follow a distinct recipe with help from a demonstrator. While these types of laboratories provide the students with valuable skills, they inhibit the student’s ability to understand or provide insight into what they are actually doing throughout the practical (Beussman 2007). This paper discusses the advantages of a ‘Mystery Death’ laboratory where the students work in groups to solve the mystery with little help from demonstrators. The students are presented with a scenario of a death and are asked to work together to design and carryout the experiments necessary for solving the mystery death. They are provided with glassware, chemicals and instruments to carry out the experiments and must finish the day's work with a presentation of their findings. This study provides an interesting insight into group work, student’s skills in the laboratory, problem solving and engaging students within a relaxed laboratory environment

CSI in a Lab: A Problem Solving Approach to Undergraduate Chemistry Practicals

With an ever demanding job market and industry complaints of grade inflation in the university sector, our graduates need more than just good grades to obtain successful employment. They need to be able to demonstrate a wide variety of skills such as problem solving, team work and the ability to work on their own initiative. This paper discusses a new type of chemistry practical that tries to incorporate all of these skills into an engaging undergraduate laboratory entitled “Mystery Death on a River”. Chemistry undergraduate labs at present often follow the cookbook recipe approach where students follow a distinct recipe with help from a demonstrator. While these types of laboratories provide the students with valuable skills, they inhibit the student’s ability to understand or provide insight into what they are actually doing throughout the practical (Beussman 2007). This paper discusses the advantages of a ‘Mystery Death’ laboratory where the students work in groups to solve the mystery with little help from demonstrators. The students are presented with a scenario of a death and are asked to work together to design and carryout the experiments necessary for solving the mystery death. They are provided with glassware, chemicals and instruments to carry out the experiments and must finish the day's work with a presentation of their findings. This study provides an interesting insight into group work, student’s skills in the laboratory, problem solving and engaging students within a relaxed laboratory environment

The Corrosion Protection of Copper and Copper Alloys using an Electrodeposited Conducting Polypyrrole Coating

Adherent polypyrrole films were electropolymerized from a near neutral sodium oxalate solution at pure Cu, CuZn and CuNi electrodes. The growth of these films was facilitated by the formation of a pseudo-passive oxalate layer. This layer was sufficiently protective to minimize dissolution of the substrate, but sufficiently conductive to enable the electropolymerization of pyrrole at the interface, and the generation of an adherent polypyrrole film. The rate of electropolymerization at the CuNi layer was reduced significantly by the formation of a nickel-rich oxide phase, however, the presence of Cu2+ increased the rate of polymer growth, enabling the formation of a thin polypyrrole layer during the early stages of polymerization. Likewise, the presence of zinc in the oxalate layer generated at the CuZn electrode reduced somewhat the rate of polymer formation. These films exhibited good corrosion protection properties in an acidified chloride solution

A Simple But Highly Selective Electrochemical Sensor for Dopamine

A modified platinum electrode was fabricated by the electropolymerization of pyrrole using a sodium p-sulphonatocalix[6]arene as the supporting electrolyte. The modified electrode acts as a reasonably sensitive electrochemical sensor for dopamine giving a linear calibration curve in the range 0.075 – 1.00 mM dopamine. The sensor shows no ability to sense the common interferent ascorbic acid, therefore the concentration for dopamine can be directly sensed in a large excess of ascorbic acid with no need to make adjustments for the signal for ascorbic acid. Investigations are included to study the mode of sensing of the modified electrode

East Asia and the global/transatlantic/Western crisis

This paper introduces the special collection on East Asia and the Global Crisis. After justifying why a focus on East Asia is appropriate, it draws out the main themes that run through the individual contributions. These are the extent to which the region is decoupling from the global economy (or the West), the increasing legitimacy of statist alternatives to neoliberal development strategies, and the impact of crises on the definition of ―region‖ and the functioning of regional institutions and governance mechanisms

Investigation of the Electrochemical Behaviour of MWCNTs in the detection of Cr(VI)

The electrochemical behaviour of a glassy carbon (GC) electrode modified with MWCNTs was investigated and characterised using K3[Fe(CN)6] as a probe. An increase in the electroactive surface area and the rate of electron transfer was observed on sonication of the MWCNTs prior to casting at the GC electrode. The modified electrode was also used in the detection of Cr(VI) in both pH 5.0 and pH 2.0 aqueous solutions. Better detection limits were obtained in the acidic solution

Remediation of chromium(VI) at polypyrrole-coated titanium

The application of conducting polypyrrole (PPy) and polyaniline (PAni) coated substrates in remediation of chromium, Cr(VI), is an area of considerable interest. Here, we discuss the implementation of PPy-coated titanium as a new material for the reduction of Cr(VI) to the less toxic trivalent state, Cr(III). An alkaline-peroxide based etching process was used to ensure the adhesion of the PPy coatings to the underlying titanium. The PPy films showed excellent resistance to acidic Cr(VI) solutions and remained adherent after continuous exposure to the solutions. In order to optimise the remediation process a number of experimental parameters were investigated, including the thickness of the PPy coating, the reduction potential used in pre-treatment of the PPy and the degree of solution agitation. The durability of the materials on exposure to the Cr(VI) test solutions made them suitable for repeated remediation experiments. Following several test-runs, the cleanup efficiency of the material was found to decrease slightly, however, increasing the exposure/experiment time resulted in significantly improved cleanup ability

CSI in a Lab: A problem Solving Approach to Undergraduate Chemistry Practicals

With an ever demanding job market and indu stry complaints of grade inflation in the university sector, o ur graduates need m ore t han jus t good grades to obtain su ccess ful employment. They need to be a b l e to demonstrate a wide variety of skills such as problem solving, team work and the ability to work on t h eir own initia tive. This paper discusses a new type of chemistry practical that tries to incorporate all of these skills in to a n engaging undergraduate la b oratory entitled “Mystery Death on a River”. Chemistry undergraduate labs a t present o f ten follow the cookbook recipe appro a ch where students follow a distin ct recipe wi th help from a de mon strator. While these type s of laboratories provide the students with valuable skills, they inhibit th e student’s ability to understand or pr o vide insight in to what they are a ctually d o i n g throughout the practical (Beussman 2007). This paper discusses the advantages of a ‘Myster y Death’ labora tory where the students work in groups to solve the mystery with little help from demonstra tors. The students are pre sent ed with a scenario of a deat h and are asked t o w o r k t ogether t o de sign and carryout the experiments necessary for solv ing the mystery death. They are provided with glassware, chemicals an d instruments to carry out the experiments and must finish the da y's work with a presentation of their findings. This study provides an interesting in sight into group work , stud e nt’s skills in the laboratory, problem solving and engaging students within a relaxed laboratory environment

Comparison of Conductivities of Bulk and Nanowire Morphologies of Electrodeposited Polypyrrole

The abstract is included in the text