scholarly journals Perfume Encapsulation via Vapor Induced Phase Separation

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 865 ◽  
Author(s):  
Mario Ammendola ◽  
Raul Rodrigo Gomez ◽  
Ricard Garcia Valls
Keyword(s):  
Phase Separation ◽  
Cellulose Acetate ◽  
Shell Structure ◽  
Encapsulation Efficiency ◽  
Empty Space ◽  
Core Shell ◽  
Active Concentration ◽  
Core Shell Structure ◽  
Tga Analysis ◽  
Exposition Time

In this study we explored the implementation of the vapor induced phase separation (VIPS) to produce cellulose acetate microcapsules for the encapsulation of a complex mix of fragrances. VIPS is a technique used for membrane preparation, but barely mentioned for microencapsulation. We compared the products from VIPS and a more common microencapsulation process, the immersion precipitation technique (IPS). The capsules prepared via VIPS show a core-shell structure with a thin polymeric shell surrounding the internally empty space, conversely to those produced via IPS, showing an incomplete spherical morphology. This can be attributed to a better control of the precipitation rate of the encapsulation material in the non-solvent thanks to the longer exposition time to the vapor. The activity and encapsulation efficiency of the capsules, obtained through TGA analysis, reached a maximum of ≈75% and ≈90%, respectively. Moreover, a growing trend between the initial active concentration and the encapsulation efficiency is noticed.

scholarly journals Facile Preparation and Characterization of Carbon Fibers with Core-Shell Structure from Graphene-Dispersed Isotropic Pitch Compounds

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 521
Author(s):  
Dong Lee ◽  
Yong-Hwan Choi ◽  
Kyong Rhee ◽  
Kap Yang ◽  
Byung-Joo Kim
Keyword(s):  
Carbon Fibers ◽  
Shell Structure ◽  
Thermal Characteristics ◽  
Surface Region ◽  
Petroleum Residue ◽  
Core Shell ◽  
Isotropic Pitch ◽  
Core Shell Structure ◽  
Tga Analysis

In this study, isotropic pitch-based carbon fibers were prepared from a mixture of petroleum residue and graphene nanoplatelets with different contents. The softening point and synthetic yield of synthesized isotropic pitches were analyzed and compared to characterize the nature of the pitches. The surface and thermal characteristics of the fibers were observed using scanning electron microscopy and thermogravimetric analysis (TGA), respectively. From the results, it was observed that the prepared carbon fibers had an interesting core-shell structure. In the TGA analysis with air, the carbon fiber having 0.1 wt.% of graphene showed a higher residue yield than that of the sample having 1.0 wt.% of graphene. This result can be explained due to the graphene being placed on the surface region of the carbon fibers and directly helping to increase the surface area of the carbon fibers, resulting in rapid oxidation due to the enhanced contact area with oxygen.

scholarly journals Effect of Solution Miscibility on the Morphology of Coaxial Electrospun Cellulose Acetate Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4419
Author(s):  
Ke Yan ◽  
Yao Le ◽  
Hu Mengen ◽  
Li Zhongbo ◽  
Huang Zhulin
Keyword(s):  
Cellulose Acetate ◽  
Shell Structure ◽  
Partial Solution ◽  
Electrospinning Process ◽  
Core Shell ◽  
Electrospinning Technique ◽  
Product Morphology ◽  
The Core ◽  
Core Shell Structure ◽  
Structural Characterizations

Coaxial electrospinning (co-electrospinning) technique has greatly expanded the universality of fabricating core-shell polymer nanofibers. However, the effect of solution miscibility on the morphology of co-electrospun products remains unclear. Herein, different cellulose acetate (CA) solutions with high solution miscibility but distinctly different electrospinnability were used to survey the effect of solution miscibility on the co-electrospinning process. The structural characterizations show that co-electrospun products are composed of nanofibers with and without the core-shell structure. This indicates that partial solution mixing occurred during the co-electrospinning process instead of absolute no-mixing or complete mixing. Importantly, the solution miscibility also shows a significant influence on the product morphology. In particular, the transformation from nanofibers to microparticles was realized with the increase of core-to-shell flow ratio during the co-electrospinning of core electrosprayable CA/dimethylacetamide (DMAc) solution and shell electrospinnable CA/acetone-DMAc (2/1, v/v) solution. Results show that the solution miscibility exerts a significant effect on not only the formation of core-shell structure but also the product morphology. This work provides a new insight for the in-depth understanding of the co-electrospinning process.

Self-supported efficient hydrogen evolution catalysts with a core-shell structure designed via phase separation

Nanoscale ◽  
2021 ◽  
Author(s):  
Zhibin Li ◽  
ruoyu wu ◽  
Yuren Wen ◽  
Fu-Kuo Chiang ◽  
X. J. Liu ◽  
...  
Keyword(s):  
Phase Separation ◽  
Hydrogen Production ◽  
Hydrogen Evolution ◽  
Shell Structure ◽  
High Performance ◽  
Cost Effective ◽  
Water Dissociation ◽  
Core Shell ◽  
Core Shell Structure

Development of cost-effective, high-performance and flexible electrocatalysts for hydrogen production is of scientific and technological importance. Catalysts with core-shell structure for water dissociation have been extensively investigated. However, most of...

Effect of Melt Overheating Treatment on the Melt Structure and Solidified Structures of Al75Bi9Sn16 Immiscible Alloy

2017 ◽  
Vol 898 ◽  
pp. 223-230
Author(s):  
Peng Jia ◽  
Yang Liu ◽  
Jin Yang Zhang ◽  
Yu Yao Ma ◽  
Chen Wu ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Shell Structure ◽  
Solidification Rate ◽  
Liquid Phase Separation ◽  
Core Shell ◽  
The Core ◽  
Immiscible Alloy ◽  
Core Shell Structure ◽  
The Impact

In this paper, the liquid phase separation and solidification process of the Al75Bi9Sn16 immiscible alloy were studied with calorimetric and resistivity methods to make the melt superheated treatment process. The impact of melt overheating treatment (MOT) on the phase constitution and solidification microstructures were investigated using X-Ray diffraction (XRD) and field emission scanning electron microscope (FESEM) to determine the structural sensitivity to the melt superheated degree, and find a new strategy for improving the forming ability of the core-shell structure of the Al75Bi9Sn16 alloy. The results show that: the liquid phase separation and precipitation of primary (Sn) phase occur in 1039K-880K and 460K-403K; the core-shell structure with Sn-Bi-rich core and Al-rich shell can be formed under conventional casting conditions; the melt overheating treatment (MOT) can promote the formation of core-shell structure by increasing solidification time t0 and decreasing the average solidification rate v.

Electrical Conductivity of Ni-YSZ Anode for SOFCs According to the Ni Powder Size Variations in Core-shell Structure

2015 ◽  
Vol 53 (4) ◽  
pp. 287-293
Author(s):  
Byung-Hyun Choi ◽  
Young Jin Kang ◽  
Sung-Hun Jung ◽  
Yong-Tae An ◽  
Mi-Jung Ji
Keyword(s):  
Electrical Conductivity ◽  
Shell Structure ◽  
Core Shell ◽  
Powder Size ◽  
Ni Powder ◽  
Core Shell Structure

Preparation of Porous Core/Shell Structure Fe$lt;inf$gt;2$lt;/inf$gt;O$lt;inf$gt;3$lt;/inf$gt;/Al Nanothermite Membrane by Template Method

2015 ◽  
Vol 30 (6) ◽  
pp. 610 ◽  
Author(s):  
ZHENG Guo-Qiang ◽  
ZHANG Wen-Chao ◽  
XU Xing ◽  
SHEN Rui-Qi ◽  
DENG Ji-Ping ◽  
...  
Keyword(s):  
Shell Structure ◽  
Template Method ◽  
Core Shell ◽  
Porous Core ◽  
Core Shell Structure

Functional properties of BaTiO3–Ni0.5Zn0.5Fe2O4 magnetoelectric ceramics prepared from powders with core-shell structure

2010 ◽  
Vol 107 (10) ◽  
pp. 104106 ◽  
Author(s):  
L. P. Curecheriu ◽  
M. T. Buscaglia ◽  
V. Buscaglia ◽  
L. Mitoseriu ◽  
P. Postolache ◽  
...  
Keyword(s):  
Functional Properties ◽  
Shell Structure ◽  
Core Shell ◽  
Core Shell Structure
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