In situ polymerization of biodegradable poly(butylene-co-succinate terephthlate) nanocomposites and their real-time tracking of microstructure

2015 ◽  
Vol 117 ◽  
pp. 121-129 ◽  
Author(s):  
Zhenzhen Wei ◽  
Jinyou Lin ◽  
Xueli Wang ◽  
Liqian Huang ◽  
Jianyong Yu ◽  
...  
Keyword(s):  
Real Time ◽  
In Situ Polymerization ◽  
Biodegradable Poly ◽  
Real Time Tracking

Enhanced Performance of Biodegradable Poly(butylene succinate)/Graphene Oxide Nanocomposites via in Situ Polymerization

Langmuir ◽  
2012 ◽  
Vol 28 (18) ◽  
pp. 7091-7095 ◽  
Author(s):  
X. W. Wang ◽  
C.-A. Zhang ◽  
P. L. Wang ◽  
J. Zhao ◽  
W. Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
In Situ Polymerization ◽  
Butylene Succinate ◽  
Biodegradable Poly

Biodegradable Poly(Lactic Acid)/Organic-Montmorillonite Nanocomposites: Preparation and Characterization

2009 ◽  
Vol 87-88 ◽  
pp. 422-426 ◽  
Author(s):  
Na Li Chen ◽  
Hui Xia Feng ◽  
He Ming Luo ◽  
Dan Zhao ◽  
Jian Hui Qiu
Keyword(s):  
Lactic Acid ◽  
In Situ Polymerization ◽  
Interlayer Spacing ◽  
Poly Lactic Acid ◽  
Organic Montmorillonite ◽  
Heat Distortion Temperature ◽  
Biodegradable Poly ◽  
Ft Ir ◽  
Silicate Layers

In this work, the biodegradable poly(lactic acid) (PLA)/organic-montmorillonite (O-MMT) nanocomposites were successfully prepared by the in situ polymerization intercalation process of D,L-lactide with organically-modified montmorillonite which was first treated by Cu cations and second treated by n-hexadecyl trimethylammonium bromide (CTAB) cations. O-MMT was characterized by FT-IR and XRD, the results showed that Cu cations and CTAB cations had been inserted to the interlayer of MMT, and the interlayer spacing of CTAB-Cu-MMT (O-MMT) increased by 1.829nm. The biodegradable PLA/O-MMT nanocomposites were characterized by XRD, SEM, FT-IR, TG, and the results showed that silicate layers were intercalated into the PLA matrix and the biodegradable PLA/O-MMT nanocomposites were of two different types: intercalated nanocomposites and exfoliated nanocomposites. This new nanocomposites frequently exhibited remarkable improvements when compared with the neat PLA matrix. Improvements could include increased heat distortion temperature, an increase in the biodegradability rate of biodegradable polymers.

scholarly journals Poly(η-caprolactone) layered silicate nanocomposites: effect of clay surface modifiers on the melt intercalation process

e-Polymers ◽  
2001 ◽  
Vol 1 (1) ◽  
Author(s):  
Nadège Pantoustier ◽  
Michaël Alexandre ◽  
Philippe Degée ◽  
Cédric Calberg ◽  
Robert Jérôme ◽  
...  
Keyword(s):  
In Situ Polymerization ◽  
Layered Silicate ◽  
Ammonium Cation ◽  
Mechanical And Thermal Properties ◽  
Melt Intercalation ◽  
Silicate Nanocomposites ◽  
Transmission Electron ◽  
Biodegradable Poly ◽  
Cation Type

AbstractNanocomposites based on biodegradable poly(e-caprolactone) (PCL) and layered silicates (montmorillonite) modified by various alkylammonium cations were prepared by melt intercalation. Depending on whether the ammonium cations contain non-functional alkyl chains or chains terminated by carboxylic acid or hydroxyl functions, microcomposites or nanocomposites were recovered as shown by X-ray diffraction and transmission electron microscopy. Mechanical and thermal properties were examined by tensile testing and thermogravimetric analysis. The layered silicate PCL nanocomposites exhibited some improvement of the mechanical properties (higher Young’s modulus) and increased thermal stability as well as enhanced flame retardant characteristics as result of a charring effect. This communication aims at reporting that the formation of PCL-based nanocomposites strictly depends on the nature of the ammonium cation and its functionality, but also on the selected synthetic route, i.e. melt intercalation vs. in situ intercalative polymerization. Typically, protonated w-aminododecanoic acid exchanged montmorillonite allowed to intercalate ε -caprolactone monomer and yielded nanocomposites upon in situ polymerization, whereas they exclusively formed microcomposites when blended with preformed PCL chains. In other words, it is shown that the formation of polymer layered silicate nanocomposites is not straightforward and cannot be predicted since it strongly depends on parameters such as ammonium cation type and functionality together with the production procedure, i.e., melt intercalation, solvent evaporation or in situ polymerization.

Enzyme-responsive fluorescent camptothecin prodrug/polysaccharide supramolecular assembly for targeted cellular imaging and in situ controlled drug release

2020 ◽  
Vol 56 (7) ◽  
pp. 1042-1045 ◽  
Author(s):  
Yu-Hui Zhang ◽  
Ying-Ming Zhang ◽  
Xianliang Sheng ◽  
Jie Wang ◽  
Yu Liu
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Real Time ◽  
Supramolecular Assembly ◽  
Controlled Drug Release ◽  
Cellular Imaging ◽  
Targeted Imaging ◽  
Real Time Tracking ◽  
Low Cytotoxicity

An enzyme-responsive polysaccharide assembly was constructed, which possesses low cytotoxicity, targeted imaging and controlled drug release, while providing a concurrent means for the real-time tracking of drug delivery.

scholarly journals Synthesis of Uniform Alkane-Filled Capsules with a High Under-Cooling Performance and Their Real-Time Optical Properties

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 199
Author(s):  
Jinyun Liu ◽  
Yong Wu ◽  
Wen Zhang ◽  
Jiawei Long ◽  
Ping Zhou ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Real Time ◽  
In Situ Polymerization ◽  
Optical Observations ◽  
Scanning Calorimetry ◽  
Surrounding Matrix ◽  
Promising Strategy ◽  
Potential Applications ◽  
Solid Form

Encapsulating under-cooling materials has been a promising strategy to address the compatibility issue with a surrounding matrix. Herein, we present the synthesis of a uniform alkane-infilled capsule system that shows obvious under-cooling properties. As demonstrating examples, n-hexadecane was selected as a liquid alkane and n-eicosane as a solid in our systems as core materials via in-situ polymerization, respectively. The under-cooling properties of capsules were investigated using differential scanning calorimetry, real-time optical observations with two polarizers, and molecular modeling. The n-hexadecane encapsulated capsules exhibited a large under-cooling temperature range of 20 °C between melt and crystallization, indicating potential applications for structure-transformation energy storage. In addition, molecular modeling calculations confirmed that the solid forms of n-hexadecane and n-eicosane are more stable than their liquid forms. From liquid to solid form, the n-hexadecane and n-eicosane release energies were 4.63 × 103 and 4.95 × 103 J·g−1, respectively.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

An Overview of Data Aggregation Architecture for Real-Time Tracking with Sensor Networks

2006 ◽  
Author(s):  
Tian He ◽  
Lin Gu ◽  
Liqian Luo ◽  
Ting Yan ◽  
John A. Stankovic ◽  
...  
Keyword(s):  
Sensor Networks ◽  
Real Time ◽  
Data Aggregation ◽  
Real Time Tracking
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