Afshad Talaie

Dynamic sensing using intelligent composite: an investigation to development of new pH sensors and electrochromic devices

Abstract A composite of two conducting polymers, polyaniline and polypyrrole, could result in much improved physical properties with respect to their applications in electrochromic devices. However, the composite has time dependant properties that made the use of dynamic computational algorithms necessary to control its behaviour. We used a platinum modified electrode as an electrochromic display device, which was integrated with a pre-trained computer for data processing and knowledge discovery. Since there is a direct relationship between the colour of the composite and its conductivity, detection of conductivity/colour has been used for prediction of pH, we have found that different parameters within the algorithms can affect the performance of our modelling resulting in a more reliable device.

Conducting polymer based pH detector: A new outlook to pH sensing technology

The development of a new pH sensing technology using conducting polymers is addressed. Three different polymers have been examined as new pH sensor materials. The resistance of polypyrrole and polyaniline have been found to be pH dependent. The composite made of these two polymeric systems suggest a promising supramolecular structure for pH sensor applications.

Application of artificial neural networks to the real-time operation of conducting polymer sensors : a pattern recognition approach

An artificial neural network (ANN)-based pattern recognition method is adopted for conducting polymer (CP) sensors. The method is capable of creating different patterns and models based on an on-line data collection from a multichannel analog/digital (AD) device. The flow of information is directed from the surface of the CP electrode into an AD device which is connected to an ANN-trained computer. The ANN software (Turbo Neuron) used in this study accepts the data as its inputs and creates the best possible patterns, based on pre-selected parameters, to classify the type of ions existing in the operational environment. The method is recommended to be used in the field of CPs where passive analytical methods have not been successful in addressing reusability of the CP electrodes.

Examination of EL and PL properties of MCHM-PPV and MEH-PPV: a study towards introduction of a new series of thin film EL devices

Abstract The effect of the side group, employed during synthesis, on the PL (photoluminescence), EL (electroluminescence) profiles and the light intensity of PPV derivatives has been investigated using MEH (methoxy-ethyl-hexyloxy) and MCHM (methoxy-cyclo-hexyl-methyloxy) as side groups. The measurements show that even the most subtle change in molecular structure of PPV has a marked improvement on the EL, PL profiles and the light emission intensity. It has been found that the PL and EL intensities of the MCHM-PPV are higher than those of MEH-PPV. MCHM-PPV also demonstrated higher light emission at lower potentials and currents.

An integrated artificial neural network/polymer-based pH sensor: a new engineering perspective to conducting polymer technology

Abstract A new approach towards the development of a novel pH sensor using electrically conducting polymers is addressed. The approach is based on computer analysis of different experimental works in which various conducting polymer-based pH electrodes are examined. In this work, we present a novel conducting polymer pH sensor by which the pH in solutions with different pH values can be detected. Since re-usability and reproducibility of conducting polymer sensors have been themselves controversial issues, we discuss the application of artificial intelligence (AI) methods, artificial neural networks (ANNs) in particular, to address and examine such an issue on the performance of the introduced pH sensor. The introduced integrated ANN/conducting polymer pH sensing system has shown much better reproducibility in detecting pH of different acidic and basic media over the conventional polymeric pH detectors. The system can be designed for pH detection in any operational environment in an online/real time manner. Having access to such a system enables us to have access to the history of a desirable chemical process with respect to the extent of the acidity of the process.

Adaptive spline modelling of observation data (ASMOD): a solution to the problems in conducting polymer-based sensors

Abstract The development of conducting polymer sensors is a multi-dimensional task. It requires the design of intelligent data processing that controls the dynamic behaviour of the polymer. It also needs a smart computerized system by which a dynamic model can be created to predict, correctly, the dynamic character of ‘unstable’ conducting polymer sensors. Using an adaptive neuro-fuzzy modelling method, it is possible to design such a computerized processing system by which a pattern and a model can be predicted.

Towards an on-line conducting polymer composite based chemical sensor using a behavioural fuzzy clustering modelling technique

A new approach towards the development of a pH sensor using a conducting polymer composite electrode is addressed. The approach is based on computer analysis of a subset of the empirical data set used for modelling the behaviour of the pH electrode. Using a fuzzy clustering algorithm the data were clustered. Then by applying a cubic spline technique the smoothest possible line was traversed between the cluster centres. The line itself represents a model for the behaviour of the composite pH electrode. Since the behaviour of the electrode depends on whether the pH is increasing or decreasing, two different models are created to represent well the system behaviour.

Data acquisition, signal processing and modelling: a study of a conducting polypyrrole formate biosensor Part 1: Batch experiment

Abstract In this paper a new computerized approach to detection of trace concentrations of formate is considered. In this approach an integrated artificial neural network (ANN) /conducting polymer biosensor is designed. The data collected (current signals) from amperometric detection of the polypyrrole formate biosensor were transferred into a MATLAB ™ environment for data and signal processing. Later the data were transferred into an ANN trained computer for modelling and prediction of output. Such an integrated ANN/polypyrrole biosensor system is capable of prediction of formate concentration based on the created models and patterns. The method has advantages of being more selective and more accurate over conventional methods.

Synthesis of new PPV based polymer and its application to display

Abstract We have synthesized PPV derivative containing an adamantane side group, poly(1-(2-ethylhexyloxy)-4-(1-adamantaneethyloxy)-2,5-phenylenevinylene, EHAE-PPV) and fabricated the segment device using this polymeric electroluminescent material. EHAE-PPV is solution processable and shows high photoluminescence intensity, probably due to the steric effect of the adamantyl group. This polymer also has exhibited good electroluminescent properties.

Introduction to a novel polymeric composite-based interface: fabrication, characterization and application

The development of a new polymeric composite interface is introduced for pH sensing application. The composite pH/R profile is compared with two other non-composite polymeric materials. It is noted that the composite performs in a promising manner over a wide range of pH. However, further improvement needs to be made to achieve more reproducible and reversible results.