Electrospun heat management polymeric materials of interest in food refrigeration and packaging

Abstract

The use of latent heat storage materials using phase change materials (PCMs) is an effective way of buffering thermal fluctuations and has the advantages of high-energy storage density and the isothermal nature of the storage process. The aim of this work was to develop slabs with energy storage capacity for their application in refrigerated foods. To this end, polycaprolactone (PCL) and polystyrene (PS) were used as encapsulating matrices of a PCM, specifically RT5 (a paraffin which has a transition temperature at 5 C), by using electrohydrodynamic processing. The effect of storage temperature (4 C and 25 C) and time on the morphology and thermal characteristics of the PCL/RT5 and PS/RT5 slabs was evaluated. Results showed that RT5 can be properly encapsulated inside both polymers, although PCL provided better encapsulation efficiency. Encapsulation efficiency was affected not only by the polymer matrix but also by storage time at 25 C. The greatest encapsulation efficiency (98.6%) and optimum heat management performance was achieved for PCL/PCM slabs stored at 4 C, corresponding to materials composed of 44 wt % of PCM (core material) and 56 wt % of the PCL shell material. These temperature buffering materials can be of great interest to preserve the quality of packaged foods and to increase efficiency and reduce energy consumption in refrigeration equipment.

Development of an encapsulated phase change material via emulsion and coaxial electrospinning

“…Similarly, to that previously reported for PLA and PCL matrices, 12,18,28 the crystallization phenomenon of PVOH/PCM hybrid structures occurred in multiple steps. In fact, while pure PCM crystallized at 5.4 8C, two crystallization temperatures were detected for the PVOH/PCM hybrid structures which can be ascribed to the multiple crystallization processes of the N-alkanes ascribed to the rotator phase transitions which are observed in these paraffins when their particle size is reduced.…”

“…Furthermore, some of the encapsulated PCM could be released during the swelling, thus decreasing the heat storage capacity of these samples. Therefore, from the results obtained in the first part of this work, it was clearly observed that hydrophilic matrices greatly improved the encapsulation efficiency of the PCM (RT5) in comparison with previous works carried out with more hydrophobic materials, although this solution provided a handling problem under environmental conditions.…”

“…In fact, while pure PCM crystallized at 5.4 8C, two crystallization temperatures were detected for the PVOH/PCM hybrid structures which can be ascribed to the multiple crystallization processes of the N-alkanes ascribed to the rotator phase transitions which are observed in these paraffins when their particle size is reduced. 12,29,30 However, the supercooling degree of PVOH/PCM hybrid structures did not differ from that obtained for the neat PCM whereas greater supercooling degree was observed for more hydrophobic matrices. 11,13,18,31 Concerning the electrospun hybrid structures prepared with surfactants, the onset temperature was the same but the melting temperature range was larger for the encapsulated PCM containing surfactants compared to the neat PCM and emulsionelectrospun structures without surfactants.…”

Electrospun curcumin-loaded protein nanofiber mats as active/bioactive coatings for food packaging applications

“…Electrospun nanofibers present particular benefits for the production of food packaging coatings, such as higher crack resistance as compared to conventional films, absence of negative impact in the flexibility and mechanical properties of the packaging material to be coated and their good adhesion properties due to their large surface to volume ratio (Fabra, Busolo, Lopez-Rubio, & Lagaron, 2013). For these reasons, electrospinning has already been effectively used in the food packaging area to generate antimicrobial coatings (Castro-Mayorga et al, 2017), high barrier structures (Fabra, Busolo, et al, 2013;, adhesive interlayers , packaging materials with 86 temperature buffering capacity (Chalco-Sandoval et al, 2017;Chalco-Sandoval, Fabra, López-Rubio, & Lagaron, 2014) and, very recently, functionalized antioxidant coatings based on α-tocopherol (Dumitriu et al, 2017;Fabra et al, 2016).…”

Multilayer packaging: Advances in preparation techniques and emerging food applications

“…Results inferred that the electrospinning process is relatively less efficient for a negatively charged solution with positive collector and more regular nanofibers resulted in positively charged solutions with the negatively charged collector. In another study, an electrospinning pilot plant equipped with humidity and temperature control unit was used with coaxial multinozzle emitter and a horizontal metallic grid as a collector (Chalco‐Sandoval, Fabra, López‐Rubio, & Lagaron, 2014; Chalco‐Sandoval et al., 2015, 2017).…”