Sophisticated techniques boost green chemistry credentials
Structural flaws in certain electricity-conducting plastics may be responsible for limiting the materials' performance, suggests new research.
The finding concerns one method employed for the construction of conjugated polymers that are used for next generation technology, in applications including optoelectronics, computing, biosensors, and power generation.
These polymers may be created using aldol condensation, a ‘greener’ method often favoured on the grounds of sustainability, versatility, cost and industrial scalability.
However, studies by a team at the University of Birmingham examined the polymers at molecular level and identified two key defects that could impact effectiveness.
Writing in Nature Communications the team outlined how structural defects could result in aldol condensation negatively affecting how well the polymer conducted electricity or converted heat into electrical energy in thermoelectric devices.
Lead author professor Giovanni Costantini likened the defects that could be created by the process to “missteps in a molecular dance”.
These could disrupt the flow of electrons through the material, reducing efficiency and reliability in devices, he explained.
“Our findings could have wide-reaching implications for the development of high-performance, flexible, low-cost electronics and help reduce reliance on rare or toxic metals in manufacturing,” he added.
Advances in analytical techniques enabled the Birmingham researchers to identify the problem for the first time, which conventional methods had been unable to spot previously.
Their approach combined scanning tunnelling microscopy (STM) with electrospray deposition (ESD) enabling them to identify how molecular building blocks connected,.
This work pinpointed specific ‘coupling’ and ‘sequence’ defects: the former resembling kinks in the polymer chain caused by building blocks connecting in the wrong orientation or position; the latter arising when the order of the building blocks is incorrect.
By adjusting the chemical design and purifying the building blocks before polymerisation, the scientists said they could “significantly reduce” the frequency of defects.
“This is a major step forward in understanding how to make better-performing, more sustainable materials for electronics. It shows that even green chemistry needs careful control to deliver the best results,” remarked Costantini.
The research was supported by funding from the Leverhulme Trust, the Royal Society, and the European Research Council.
Pic: High-resolution STM image showing sequence defects at the single molecule level (Credit: Dr Xiaocui Wu)
Related Content
When plasma leaves the laboratory
The orbital laboratory is evolving into something more ambitious, a controlled industrial environment for producing next-generation materials, explains Ed Smith and Andrew Griffiths. …
Lab gloves could inflate microplastics readings suggests study
Scientists may be overestimating their assessments of microplastics pollution, with the cause lying literally in their own hands, suggests a …
Collaborators apply intelligence to create smart telescopes
Britain’s Hartree Centre facility has teamed with one of Africa’s leading astronomical institutions to develop an ‘intelligent observatory’ programme featuring …
