Dynamic rheology studies of in situ polymerization process of polyacrylamide–cellulose nanocrystal composite hydrogels

2010 ◽  
Vol 289 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Chengjun Zhou ◽  
Qinglin Wu ◽  
Quanguo Zhang
Author(s):  
Jolly Bhadra ◽  
Hemalatha Parangusan ◽  
Zubair Ahmad ◽  
Shoaib Mallick ◽  
Farid Touati ◽  
...  

PANI coated Cu-ZnS porous microsphere structures have been synthesized by hydrothermal method and in-situ polymerization process. The synthesized composite is characterized by different techniques in order to study the structural, morphological and surface absorption properties. The experimental observation demonstrates that the PANI/1%Cu-ZnS composite has better sensitivity, fast response and good stability as compared to pure PANI and other PANI/CuZnS compositions. Finally, PANI/1% Cu-ZnS composite has been found to be optimized for the humidity sensors due to its well-distributed roughness, porosity and hydrophilicity. The average response and recovery times of the PANI/1% Cu-ZnS are found to be 42 s and 24 s, respectively, which outperform recent results.


2010 ◽  
Vol 148-149 ◽  
pp. 1547-1550 ◽  
Author(s):  
Hua Lan Wang ◽  
Qing Li Hao ◽  
Xi Feng Xia ◽  
Zhi Jia Wang ◽  
Jiao Tian ◽  
...  

A graphene oxide/polyaniline composite was synthesized by an in situ polymerization process. This product was simply prepared in an ethylene glycol medium, using ammonium persulfate as oxidant in ice bath. The composite was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-Ray photoelectron spectroscopy, Raman spectroscopy and electrochemical test. The composite material showed a good electrochemical performance.


2013 ◽  
Vol 395-396 ◽  
pp. 121-124
Author(s):  
Jia Qi Lin ◽  
Pan Pan Zhang ◽  
Wen Long Yang

A functional potassium sodium niobate/polyimide (KNN/PI) composite films were prepared in this paper. KNN fillers are well dispersed in the PI matrix without any accumulation through in situ polymerization process. The optical band baps of the hybrid films become smaller with the increase of KNN loading. The optical band baps of the films with 0-20 wt% KNN filler are estimated to be 2.61 eV, 2.57 eV, 2.52 eV, 4.29 eV, 2.35 eV respectively.


2010 ◽  
Vol 160 (23-24) ◽  
pp. 2670-2674 ◽  
Author(s):  
Jun-Wei Zha ◽  
Zhi-Min Dang ◽  
Tao Zhou ◽  
Hong-Tao Song ◽  
George Chen

2019 ◽  
Vol 14 ◽  
pp. 155892501982744 ◽  
Author(s):  
Juan Xie ◽  
Wei Pan ◽  
Zheng Guo ◽  
Shan Shan Jiao ◽  
Ling Ping Yang

Polypyrrole/cotton composites have substantial application potential in flexible heating devices due to their flexibility, high conductivity, and thermal stability. In this context, a series of flexible polypyrrole/cotton fabrics were intrinsically prepared using in situ polymerization process with the different Py/FeCl3 concentration ratios. To investigate their structural and morphological properties, thermal stability, tensile strength, conductivity, and heat-generating property, the composite fabrics were subjected to Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermo-gravimetric analysis, mechanical properties, and resistivity measurements. The results showed that polypyrrole/cotton fabrics exhibited a low resistivity of 0.37 Ω cm. Temperature–time curve showed that temperature of the polypyrrole/cotton fabrics increased very quickly from room temperature to a steady-state maximum temperature of 168.3°C within 3 min at applied voltage of 5 V. Tensile strength of polypyrrole/cotton composites reached to 58 MPa, which far surpassed raw cotton fabrics. Therefore, polypyrrole/cotton fabrics have exhibited high electrical, thermal properties, and mechanical strength, which can be utilized as an ideal flexible heating element.


2002 ◽  
Vol 726 ◽  
Author(s):  
Fabrice Leroux ◽  
El Mostafa Moujahid ◽  
Joël Cellier ◽  
Jean-Pierre Besse

AbstractInterleaved polystyrene sulfonate polymer between a layered double hydroxide of composition Zn2Al(OH)6Cl. nH2O are prepared either by direct exchange or by in-situ polymerization of the monomer. The latter is confirmed by 13C CP-MAS solid state NMR spectroscopy. This technique provides also clear evidence of the strong interaction between the incorporated monomer and the LDH inorganic framework. A shielding of the aromatic carbon attached to the sulfonate group is observed, this is transmitted through the carbonaceous skeleton to the vinylic carbon. The 2D structure is stabilized with the presence of organic moieties, and even more through the in-situ polymerization process, as exemplified with the conversion from Oh to Td aluminium cations environment. However the difference is diminished with the heating process. The exfoliation/restacking process is found to be here unappropriate, giving rise to ill-defined materials.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 302 ◽  
Author(s):  
Boxiang Wang ◽  
Song Zhang ◽  
Yifan Wang ◽  
Bo Si ◽  
Dehong Cheng ◽  
...  

At present, Antheraea pernyi silk fibroin (ASF) has attracted research efforts to investigate it as a raw material for fabrication of biomedical devices because of its superior cytocompatibility. Nevertheless, native ASF is not easily processed into a hydrogel without any crosslinking agent, and a single hydrogel shows poor mechanical properties. In this paper, a series of ASF/poly (N-isopropylacrylamide) (PNIPAAm) composite hydrogels with different ASF contents were manufactured by a simple in situ polymerization method without any crosslinking agent. Meanwhile, the structures, morphologies and thermal properties of composite hydrogels were investigated by XRD, FTIR, SEM, DSC and TGA, respectively. The results indicate that the secondary structure of silk in the composite hydrogel can be controlled by changing the ASF content and the thermal stability of composite hydrogels is enhanced with an increase in crystalline structure. The composite hydrogels showed similar lower critical solution temperatures (LCST) at about 32 °C, which matched well with the LCST of PNIPAAm. Finally, the obtained thermosensitive composite hydrogels exhibited enhanced mechanical properties, which can be tuned by varying the content of ASF. This strategy to prepare an ASF-based responsive composite hydrogel with enhanced mechanical properties represents a valuable route for developing the fields of ASF, and, furthermore, their attractive applications can meet the needs of different biomaterial fields.


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