Preparation of a synergistically stabilized oil-in-water paraffin Pickering emulsion for potential application in wood treatment

Holzforschung ◽  
2018 ◽  
Vol 72 (6) ◽  
pp. 489-497 ◽  
Author(s):  
Jun Jiang ◽  
Jinzhen Cao ◽  
Wang Wang ◽  
Haiying Shen

AbstractPickering emulsions (emulsions stabilized by solid-state additives) are attractive as they have strong similarities with traditional surfactant-based emulsions. In this study, an oil-in-water (O/W) paraffin Pickering emulsion system with satisfying stability and small droplet size distribution was developed by hydrophilic silica particles and traditional surfactants as mixed emulsifiers. The droplet morphology and size distribution were observed by optical microscopy and a laser particle analyzer. The emulsion stability was improved and the droplet size was reduced after addition of a suitable amount of silica particles. The silica concentration of 1% showed the optimal effect among all the levels observed (0.1, 0.5, 1 and 2%). Wood was impregnated with the prepared emulsion, and the chemical and morphological properties of the product were investigated by Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) combined with energy-dispersed X-ray analysis (SEM-EDXA). Moreover, the hydrophobicity, thermal properties, surface hardness, axial compression strength (CS) and dynamic mechanical properties were tested. The silica was evenly distributed in the wood cell wall and thus there was a synergistic positive effect from the paraffin and silica in the cell wall leading to better hydrophobicity, improved surface hardness and mechanical properties including the thermal stability.

2021 ◽  
Vol 9 ◽  
Author(s):  
Liliya Kotliarevski ◽  
Karthik Ananth Mani ◽  
Reut Amar Feldbaum ◽  
Noga Yaakov ◽  
Eduard Belausov ◽  
...  

This study presents an individual encapsulation of fungal conidia in an oil-in-water Pickering emulsion at a single-conidium encapsulation yield of 44%. The single-conidium encapsulation yield was characterized by analysis of confocal microscopy micrographs. Mineral oil-in-water emulsions stabilized by amine-functionalized titania dioxide (TiO2-NH2 or titania-NH2) particles were prepared. The structure and the stability of the emulsions were investigated at different compositions by confocal microscopy and a LUMiSizer® respectively. The most stable emulsions with a droplet size suitable for single-conidium encapsulation were further studied for their individual encapsulation capabilities. The yields of individual encapsulation in the emulsions; i.e., the number of conidia that were individually encapsulated out of the total number of conidia, were characterized by confocal microscopy assay. This rapid, easy to use approach to single-conidium encapsulation, which generates a significantly high yield with eco-friendly titania-based emulsions, only requires commonly used emulsification and agitation methods.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1071 ◽  
Author(s):  
Yu-Jin Cho ◽  
Dong-Min Kim ◽  
In-Ho Song ◽  
Ju-Young Choi ◽  
Seung-Won Jin ◽  
...  

A pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA)-based oligoimide (PMDA-ODA) was synthesized by a one-step procedure using water as a solvent. The PMDA-ODA particles showed excellent partial wetting properties and were stably dispersed in both water and oil phases. A stable dispersion was not obtained with comparison PMDA-ODA particles that were synthesized by a conventional two-step method using an organic solvent. Both oil-in-water and water-in-oil Pickering emulsions were prepared using the oligoimide particles synthesized in water, and the size of the emulsion droplet was controlled based on the oligoimide particle concentration. The oligoimide particles were tested to prepare Pickering emulsions using various kinds of oils. The oil-in-water Pickering emulsions were successfully applied to prepare microcapsules of the emulsion droplets. Our new Pickering emulsion stabilizer has the advantages of easy synthesis, no need for surface modification, and the capability of stabilizing both oil-in-water and water-in-oil emulsions.


2021 ◽  
Author(s):  
Amir Varamesh ◽  
Ragesh Prathapan ◽  
Ali Telmadarreie ◽  
Jia Li ◽  
Keith Gourlay ◽  
...  

Abstract There has been significant interest over recent years in the production and application of sustainable and green materials. Among these, nanocellulose has incurred great interest because of its exceptional properties and wide range of potential applications, including in Pickering emulsions. However, the production cost of these cellulosic materials has limited their application. In this study, the capability of a new type of cheaper cellulosic material, cellulose filaments (CFs), in formulating stable oil in water Pickering emulsions was investigated and compared with three conventional nanocelluloses, namely cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs) and TEMPO-oxidized CNFs (TEMPO-CNFs). Results showed that CFs can provide stable surfactant-free emulsions over wide ranges of salt concentration (0 – 500 mM) and pH (2 – 10), as indicated by the near constant oil droplet size and dewatering index of the emulsions. This is due to the ability of CFs to strongly adsorb to the oil and water interface, as evidenced by visualizing labeled CFs with engineered carbohydrate-binding module (CBM2a) conjugated with green fluorescent protein (CBM2a-eGFP) under fluorescent microscopy. Compared to the emulsions stabilized by other types of nanocelluloses, the CFs-stabilized emulsion demonstrated a larger average droplet size and comparable (with CNFs) or better (than CNCs and TEMPO-CNFs) stability, which is partially attributed to the higher viscosity of continuous phase in the presence of CFs. The results of this study demonstrate the use of CFs as a novel and cheaper cellulosic material for stabilizing emulsions, which opens the door to a range of markets from the food industry to engineering applications.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1048
Author(s):  
Junjing Wang ◽  
Morane Jousse ◽  
Jitesh Jayakumar ◽  
Alejandro Fernández-Arteaga ◽  
Silvia de Lamo-Castellví ◽  
...  

There is a pressing need to extend the knowledge on the properties of insect protein fractions to boost their use in the food industry. In this study several techno-functional properties of a black soldier fly (Hermetia illucens) protein concentrate (BSFPC) obtained by solubilization and precipitation at pH 4.0–4.3 were investigated and compared with whey protein isolate (WPI), a conventional dairy protein used to stabilize food emulsions. The extraction method applied resulted in a BSFPC with a protein content of 62.44% (Kp factor 5.36) that exhibited comparable or higher values of emulsifying activity and foamability than WPI for the same concentrations, hence, showing the potential for emulsion and foam stabilization. As for the emulsifying properties, the BSFPC (1% and 2%) showed the capacity to stabilize sunflower and lemon oil-in-water emulsions (20%, 30%, and 40% oil fraction) produced by dynamic membranes of tunable pore size (DMTS). It was proved that BSFPC stabilizes sunflower oil-in-water emulsions similarly to WPI, but with a slightly wider droplet size distribution. As for time stability of the sunflower oil emulsions at 25 °C, it was seen that droplet size distribution was maintained for 1% WPI and 2% BSFPC, while for 1% BSFPC there was a slight increase. For lemon oil emulsions, BSFPC showed better emulsifying performance than WPI, which required to be prepared with a pH 7 buffer for lemon oil fractions of 40%, to balance the decrease in the pH caused by the lemon oil water soluble components. The stability of the emulsions was improved when maintained under refrigeration (4 °C) for both BSFPC and WPI. The results of this work point out the feasibility of using BSFPC to stabilize O/W emulsions using a low energy system.


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