Antimicrobial functionalization of Ca alginate‐coconut oil latent heat storing microcapsules by Ag nanoparticles. (6th August 2020)

• Record Type: Journal Article
• Authors: Németh, Bence; Németh, Ágnes S.; Ujhidy, Aurél; Tóth, Judit; Trif, László; Jankovics, Hajnalka; Kriszt, Balázs; Dobolyi, Csaba; May, Zoltán; Gyenis, János; Feczkó, Tivadar
• Is Part Of: International journal of energy research. Volume 44:Number 14(2020)
• Page Start: 11998
• Page End: 12014
• Publication Date: 2020-08-06
• Subjects: Ag nanoparticles -- antimicrobial effect -- calcium alginate -- coconut oil -- eco‐friendly microcapsules -- energy storage -- phase change materials; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.5848
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: Latent heat storage by phase change materials (PCM) is a promising way of thermal energy storage for equilibrating the daily fluctuation of temperature in office‐ and home buildings. Bio‐originated compounds have got great importance to evade further plastic contamination all over the world. Durability of biodegradable natural materials by means of environmentally friendly agents is an exciting challenge. In this study Ca alginate‐coconut oil eco‐friendly core‐shell PCM microcapsules were functionalized with Ag nanoparticles, following their synthesis using harmless reducing agents. Throughout the preparation of the PCM microcapsules by repeated interfacial coacervation/crosslinking procedure, the Ag nanoparticles were homogeneously dispersed in the Ca alginate shell. High coconut oil content was achieved in the Ag nanoparticle‐loaded microcapsules, which was not influenced by the Ag nanoparticle content. The high PCM content resulted in correspondingly high latent heat storing capability. The freezing and melting heat storing capacities were in the range of 83.6 and 85.6 J/g, as well as 89.7 to 92.6 J/g, respectively, matching to the extremely high PCM content in the range of 82.7% to 84.8% (m/m). Leaking of the heat storing microcapsules was not observed after 200 heating‐cooling cycles. The Ag nanoparticle content did not influence the PCM ratio of the microcapsules, although as expected their antimicrobial potential was significantly enhanced by it. The highest Ag nanoparticle loading, that was 1.3% (m/m) related to the total mass of microcapsules, exerted excellent antibacterial and antifungal impact. Abstract : Fully bio‐originated Ca alginate microcapsules loaded with coconut oil phase change material (PCM) were functionalized by Ag nanoparticles synthesized using harmless agents during the silver nitrate reduction. The Ag nanoparticles were homogeneously dispersed in the shell of microcapsules, and their entrapment did not influence the PCM microencapsulation in the latent heat storing microcapsules. The microcapsules contained extremely high amount of PCM without leakage in thermal cycling, and exerted excellent antibacterial and antifungal impact due to the Ag nanoparticles.