scholarly journals Synthesis Antifreezing and Antidehydration Organohydrogels: One-Step In-Situ Gelling versus Two-Step Solvent Displacement

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2670
Author(s):  
Chun Li ◽  
Xiaobo Deng ◽  
Xiaohu Zhou
Keyword(s):  
Mechanical Properties ◽  
Comparative Study ◽  
Dispersion Medium ◽  
Synthesis Strategy ◽  
Solvent Displacement ◽  
One Step ◽  
Physical Interactions ◽  
The Comparative Study ◽  
In Situ Gelling

Organohydrogels with distinct antifreezing and antidehydration properties have aroused great interest among researchers, and various organohydrogels and organohydrogel-based applications have emerged recently. There are two popular synthesis strategies to prepare these antifreezing and antidehydration organohydrogels: the in-situ gelling and the solvent displacement strategies. Although both strategies have been widely applied, there is a lack of comparative study of these two strategies. In this work, to elucidate the comparative advantages of the two synthesis strategies, we studied and compared the mechanical and environmental tolerant properties of the organohydrogels synthesized from both strategies. The glycerol-based and ethylene glycol-based chemical polyacrylamide (PAAm) organohydrogel and the glycerol-based physical gelatin organohydrogel were synthesized and studied. Through the comparative study, we have found that the organohydrogels from different strategies with the same dispersion medium showed similar antifreezing and antidehydration properties but different mechanical properties. The mechanical properties of these organohydrogels are influenced by two opposite factors for each strategy: the enhanced physical interactions induced strengthening and solvent effect or swelling induced weakening. We hope this study may provide a better understanding of the synthesis strategies of organohydrogels and provide a valuable guide to choose the suitable synthesis strategy for each application.

On effect of chemical-assisted mechanical blending of barium titanate and graphene in PVDF for 3D printing applications

2020 ◽  
pp. 089270572094537
Author(s):  
Ravinder Sharma ◽  
Rupinder Singh ◽  
Ajay Batish
Keyword(s):  
Mechanical Properties ◽  
Barium Titanate ◽  
3D Printing ◽  
Comparative Study ◽  
Process Parameters ◽  
Processing Temperature ◽  
Melt Mixing ◽  
Twin Screw ◽  
3D Printed ◽  
The Comparative Study

The polyvinylidene difluoride + barium titanate (BaTiO3) +graphene composite (PBGC) is one of the widely explored thermoplastic matrix due to its 4D capabilities. The number of studies has been reported on the process parameters of twin-screw extruder (TSE) setup (as mechanical blending technique) for the development of PBGC in 3D printing applications. But, hitherto, little has been reported on chemical-assisted mechanical blending (CAMB) as solution mixing and melt mixing technique combination for preparation of PBGC. In this work, for preparation of PBGC feedstock filaments, CAMB has been used. Also, the effect of process parameters of TSE on the mechanical, dimensional, morphological, and thermal properties of prepared filament of PBGC have been explored followed by 3D printing. Further, a comparative study has been reported for the properties of prepared filaments with mechanically blended composites. Similarly, the mechanical properties of 3D printed parts of chemically and mechanically blended composites have been compared. The results of tensile testing for CAMB of PBGC show that the filament prepared with 15% BaTiO3 is having maximum peak strength 43.00 MPa and break strength 38.73 MPa. The optical microphotographs of the extruded filaments revealed that the samples prepared at 180°C extruder temperature and 60 r/min screw speed have minimum porosity, as compared to filaments prepared at high extruder temperature. Further, the results of the comparative study revealed that the filaments of CAMB composites show better mechanical properties as compared to the filaments of mechanically mixed composites. However, the dimensional properties were almost similar in both cases. It was also found that the CAMB composites have better properties at low processing temperature, whereas mechanically blended composites show better results at a higher temperature. While comparing 3D printed parts, tensile strength of specimens fabricated from CAMB was more than the mechanically blended PBGC.

Thermosensitive antibacterial Ag nanocomposite hydrogels made by a one-step green synthesis strategy

2016 ◽  
Vol 40 (8) ◽  
pp. 6650-6657 ◽  
Author(s):  
Haoyang Jiang ◽  
Gongzheng Zhang ◽  
Bo Xu ◽  
Xianqi Feng ◽  
Quanming Bai ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Stabilizing Agent ◽  
Nanocomposite Hydrogels ◽  
Synthesis Strategy ◽  
Hydrogel Matrix ◽  
One Step

Clay nanosheets act as a catalyst and stabilizing agent for rapid in situ synthesis of silver nanoparticles in a hydrogel matrix.

Poly(vinyl alcohol)/graphene oxide nanocomposites prepared by in situ polymerization with enhanced mechanical properties and water vapor barrier properties

RSC Advances ◽  
2016 ◽  
Vol 6 (55) ◽  
pp. 49448-49458 ◽  
Author(s):  
Jiaojiao Ma ◽  
Ying Li ◽  
Xiande Yin ◽  
Yu Xu ◽  
Jia Yue ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Vinyl Alcohol ◽  
In Situ Polymerization ◽  
Barrier Properties ◽  
Poly Vinyl Alcohol ◽  
Water Vapor Barrier ◽  
One Step ◽  
Polymerization Method

A novel and one-stepin situpolymerization method for preparing the poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposites.

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