Effect of MWCNTs Functionalization on Thermal, Electrical, and Ammonia-Sensing Properties of MWCNTs/PMMA and PHB/MWCNTs/PMMA Thin Films Nanocomposites

• Published in: Nanomaterials (Basel, Switzerland) Vol. 11; no. 10; p. 2625
• Main Authors: Qazi, Raina Aman, Khattak, Rozina, Ali Shah, Luqman, Ullah, Rizwan, Khan, Muhammad Sufaid, Sadiq, Muhammad, Hessien, Mahmoud M., El-Bahy, Zeinhom M.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 06.10.2021; MDPI
• Subjects: Adsorption; Ammonia; ammonia sensors; Biodegradability; Biodegradation; Capacitance; Carbon; Dispersion; Gases; Humidity; Interfacial bonding; Mechanical properties; Molecular weight; Multi wall carbon nanotubes; multiwalled carbon nanotubes; Nanocomposites; Nanotechnology; Nanotubes; poly(methyl methacrylate); Poly-3-hydroxybutyrate; Polyhydroxybutyrate; Polymers; Polymethyl methacrylate; Polymethylmethacrylate; Sensors; Synthesis; Thermal properties; thermal stability; Thermodynamic properties; Thin films
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano11102625

Partially biodegradable polymer nanocomposites Poly(3-Hydroxybutyrate) (PHB)/MultiwalledCarbon Nanotubes (MWCNTs)/Poly(Methyl Methacrylate) (PMMA)and non-biodegradable nanocomposites (MWCNTs/PMMA) were synthesized, and their thermal, electrical, and ammonia-sensing properties were compared. MWCNTs were chemically modified to ensure effective dispersion in the polymeric matrix. Pristine MWCNTs (p-MWCNTs) were functionalized with –COOH (a-MWCNTs) and amine groups (f-MWCNTs). Then, PHB grafted multiwalled carbon nanotubes (g-MWNTs) were prepared by a ‘grafting to’ technique. The p-MWCNTs, a-MWCNTs, f-MWCNTs, and g-MWCNTs were incorporated into the PMMA matrix and PMMA/PHB blend system by solution mixing. The PHB/f-MWCNTs/PMMA blend system showed good thermal properties among all synthesized nanocomposites. Results from TGA and dTGA analysis for PHB/f-MWCNTs/PMMA showed delay in T5 (about 127 °C), T50 (up to 126 °C), and Tmax (up to 65 °C) as compared to neat PMMA. Higher values of frequency capacitance were observed in nanocomposites containing f-MWCNTs and g-MWCNTs as compared to nanocomposites containing p-MWCNTs and a-MWCNTs. This may be attributed to their excellent interaction and good dispersion in the polymeric blend. Analysis of ammonia gas-sensing data showed that PHB/g-MWCNTs/PMMA nanocomposites exhibited good sensitivity (≈100%) and excellent repeatability with a constant response. The calculated limit of detection (LOD) is 0.129 ppm for PHB/g-MWCNTs/PMMA, while that of all other nanocomposites is above 40 ppm.