Supervisors: Prof. Fabio Di Francesco
Title: Smart Chemical Sensors
Abstract: The development of a wireless volatile amine sensor is the main topic of my PhD.
The project is based on a PRIN project that involves the realization of a chemiresistive detector to monitor volatile amines emitted during fish ageing. Carbon nanostructured materials such as graphene (G), reduced graphene oxide (rGO) and single- and multi-walled carbon nanotubes (SWNT and MWNT respectively) have been selected as promising conductive and sensitive materials to be exploited for the realization of the sensor.
The useful feature of these materials is that their electrical conductivity is extremely sensitive to changes in the local environment. The basic idea is therefore the development of a resistive-based chemical sensor exploiting and improving this excellent property.
Several papers [1,2] report the good property of graphene and carbon nanotubes for gas sensing, and most research refers to graphene dispersed in polymeric matrices. Anyway the realization of a selective and efficient sensor is challenging. Several criteria for a good gas sensor are generally reported: High sensitivity and selectivity, fast response time and recovery time, low analyst consumption, low operating temperature and temperature independence, stability in performances.
In order to improve the sensitivity and selectivity of carbon nanomaterials-based sensors for certain analytes, functionalization with selectors (functional groups intended to interact with particular molecules) is usually required. This can be done in different ways depending on the goal of the work. Non-covalent and covalent functionalization can be exploited in order to get a material with particular features like different polarity, chemical reactivity, mechanical resistance. Furthermore the main problem of working with carbon nanomaterials is their poor wettability and poor dispersibility/solubility in most organic solvents. Changing the surface properties of graphene and carbon nanotubes by functionalization, pretty good dispersions in different solvents or water may be achieved as well.
Within this project different functionalizing approaches are being studied and gas sensing tests are performed.
1. Hyeun Joong Yoon et al., Sensors and Actuators B: Chemical, 157 (2011) 310–313
2. Yun Wang and John T. W. Yeow, Journal of Sensors, Volume 2009 (2009)
Baldoli, I.; Mazzocchi, T.; Paoletti, C.; Ricotti, L.; Salvo, P.; Dini, V.; Laschi, C.; Di Francesco, F.; Menciassi, A. Pressure mapping with textile sensors for compression therapy monitoring, submitted