Effect of the shell-forming polymer ratio on the encapsulation of tea tree oil by complex coacervation as a natural biocide

Abstract

The aim of this study was to develop footwear materials with antimicrobial properties using microencapsulated Tea Tree oil (TTO) as a natural biocide. For that purpose, gelatine-carboxymethylcellulose based microcapsules containing TTO were synthesised by a complex coacervation process. Furthermore, the influence of the gelatine (G)/sodium carboxymethylmethyl cellulose (CMC) ratio (G/C) on the microcapsule properties, as well as in the microencapsulation oil efficiency, was evaluated. The microcapsules were characterised by different experimental techniques and applied to footwear materials (leather and textile) to evaluate their performance. The microcapsule durability under different conditions, such as rubbing and ironing, was analysed in order to simulate shoe manufacturing and shoe wearing. The properties of the microcapsules obtained by complex coacervation, using gelatine and sodium carboxymethylcellulose as shell-forming polymers, are determined by the ratio between those two polymers (G/C). The results obtained showed a notable effect of G/C ratio on the formation of the coacervate during the synthesis process and also on the encapsulation efficiency of the antimicrobial oil, with the optimal value for the G/C ratio being around 10.

Microencapsulation of tea tree oil by spray‐drying with methyl cellulose as the emulsifier and wall material together with chitosan/alginate

“…Ge prepared TTO liposome with soybean phosphatidylcholine and cholesterol, where Tween 80 was used as the emulsifier . TTO has also been encapsulated through complex coacervation using carbohydrate polymers (such as gelatin, sodium, sodium alginate, carboxymethyl cellulose, and quaternary ammonium salt of chitosan) as the wall materials, followed by crosslinking with formaldehyde/glutaraldehyde or CaCl 2 . Surfactants or crosslinkers are used in above references, which increases the unsafety of TTO during application.…”

Merging Footwear Design and Functionality

“…This could be, for example, achieved by incorporating various products with therapeutical and/or antimicrobial properties, such as essential oils, which could provide constant care for the feet, as well as a new approach to traditional footwear [18]. In addition, oils are generally used for their antimicrobial, antifungal, moisturizing, regenerative, and aromatic properties in the care of feet [2].…”

“…Apart from basic materials, numerous other materials are used in footwear manufacture, for uppers and bottom stock as well as for the inner parts of the footwear. A growing number of new technologies and procedures have emerged in recent decades in this area, including innovative smart functionalities, which have resulted in a new concept of active footwear [2]. A broad selection of various footwear models has been offered to the customers, and the choice of materials, functional segments, and additional fi nishes, such as antimicrobial and water repellent, play an important role in fi nal selection and purchase [3].…”

Scent properties by natural fragrance microencapsulation for footwear applications

“…A protein and a polysaccharide are generally used, such as gelatine and carboxymethylcellulose (CMC). In the microencapsulation process by coacervation, the pH is a key parameter along with the relative ratio in which the colloids and the total polymeric concentration are mixed …”

“…In the microencapsulation process by coacervation, the pH is a key parameter along with the relative ratio in which the colloids and the total polymeric concentration are mixed. 12 The work reported here aimed to study natural fragrance microencapsulation using the in situ polymerisation and complex coacervation techniques, to be incorporated in various footwear components such as insoles, lining and packaging. Furthermore, the feasibility of the incorporation of microcapsules into footwear materials to develop new products with aromatic properties was analysed.…”