Star Polymers via Cross-Linking Amphiphilic Macroinitiators by AGET ATRP in Aqueous Media

2009 ◽  
Vol 131 (30) ◽  
pp. 10378-10379 ◽  
Author(s):  
Wenwen Li ◽  
Krzysztof Matyjaszewski
Keyword(s):  
Aqueous Media ◽  
Star Polymers ◽  
Cross Linking ◽  
Aget Atrp

scholarly journals Double-Cross-Linked Networks Based on Methacryloyl Mucin

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1706
Author(s):  
Elena Olăreț ◽  
Brîndușa Bălănucă ◽  
Andra Mihaela Onaș ◽  
Jana Ghițman ◽  
Horia Iovu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Chemical Modification ◽  
Structural Modification ◽  
Aqueous Media ◽  
Cross Linking ◽  
Ph Values ◽  
Acid Aqueous Solution ◽  
Reaction Media ◽  
Double Cross

Mucin is a glycoprotein with proven potential in the biomaterials field, but its use is still underexploited for such applications. The present work aims to produce a synthesis of methacryloyl mucin single-network (SN) hydrogels and their double-cross-linked-network (DCN) counterparts. Following the synthesis of the mucin methacryloyl derivative, various SN hydrogels are prepared through the photopolymerization of methacrylate bonds, using reaction media with different pH values. The SN hydrogels are converted into DCN systems via supplementary cross-linking in tannic acid aqueous solution. The chemical modification of mucin is described, and the obtained product is characterized; the structural modification of mucin is assessed through FTIR spectroscopy, and the circular dichroism and the isoelectric point of methacryloyl mucin is evaluated. The affinity for aqueous media of both SN and DCN hydrogels is estimated, and the mechanical properties of the systems are assessed, both at macroscale through uniaxial compression and rheology tests and also at microscale through nanoindentation tests.

scholarly journals Uptake of Methylene Blue from Aqueous Solution by Pectin–Chitosan Binary Composites

2020 ◽  
Vol 4 (3) ◽  
pp. 95
Author(s):  
Dexu Kong ◽  
Lee D. Wilson
Keyword(s):  
Methylene Blue ◽  
Aqueous Media ◽  
Dye Adsorption ◽  
Adsorption Properties ◽  
Point Of Zero Charge ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Adsorption Sites ◽  
Biopolymer Composites

To address the need to develop improved hybrid biopolymer composites, we report on the preparation of composites that contain chitosan and pectin biopolymers with tunable adsorption properties. Binary biopolymer composites were prepared at variable pectin–chitosan composition in a solvent directed synthesis, dimethyl sulfoxide (DMSO) versus water. The materials were characterized using complementary methods (infrared spectroscopy, thermal gravimetric analysis, pH at the point-of-zero charge, and dye-based adsorption isotherms). Pectin and chitosan composites prepared in DMSO yielded a covalent biopolymer framework (CBF), whereas a polyelectrolyte complex (PEC) was formed in water. The materials characterization provided support that cross-linking occurs between amine groups of chitosan and the –COOH groups of pectin. CBF-based composites had a greater uptake of methylene blue (MB) dye over the PEC-based composites. Composites prepared in DMSO were inferred to have secondary adsorption sites for enhanced MB uptake, as evidenced by a monolayer uptake capacity that exceeded the pectin–chitosan PECs by 1.5-fold. This work provides insight on the role of solvent-dependent cross-linking of pectin and chitosan biopolymers. Sonication-assisted reactions in DMSO favor CBFs, while cross-linking in water yields PECs. Herein, composites with tunable structures and variable physicochemical properties are demonstrated by their unique dye adsorption properties in aqueous media.

Core hyper-cross-linked star polymers from block polymer micelle precursors

2020 ◽  
Vol 11 (45) ◽  
pp. 7178-7184
Author(s):  
Jongmin Park ◽  
Stefan J. D. Smith ◽  
Colin D. Wood ◽  
Xavier Mulet ◽  
Myungeun Seo
Keyword(s):  
Star Polymers ◽  
Cross Linking ◽  
Polymer Micelle ◽  
Polymer Micelles ◽  
Block Polymer

Hyper-cross-linking of a core of block polymer micelles produces core cross-linked polymer with a spacious hyper-cross-linked core, which is solution-processible.

scholarly journals A Direct Silanization Protocol for Dialdehyde Cellulose

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2458 ◽  
Author(s):  
Arianna Lucia ◽  
Markus Bacher ◽  
Hendrikus W. G. van Herwijnen ◽  
Thomas Rosenau
Keyword(s):  
Aqueous Media ◽  
Hydroxyl Group ◽  
Cross Linking ◽  
Cellulose Derivatives ◽  
Reaction Conditions ◽  
Cellulose Structure ◽  
Dialdehyde Cellulose ◽  
Potential Applications ◽  
The Common ◽  
Hydrolysis Of

Cellulose derivatives have many potential applications in the field of biomaterials and composites, in addition to several ways of modification leading to them. Silanization in aqueous media is one of the most promising routes to create multipurpose and organic–inorganic hybrid materials. Silanization has been widely used for cellulosic and nano-structured celluloses, but was a problem so far if to be applied to the common cellulose derivative “dialdehyde cellulose” (DAC), i.e., highly periodate-oxidized celluloses. In this work, a straightforward silanization protocol for dialdehyde cellulose is proposed, which can be readily modified with (3-aminopropyl)triethoxysilane. After thermal treatment and freeze-drying, the resulting product showed condensation and cross-linking, which was studied with infrared spectroscopy and 13C and 29Si solid-state nuclear magnetic resonance (NMR) spectroscopy. The cross-linking involves both links of the hydroxyl group of the oxidized cellulose with the silanol groups (Si-O-C) and imine-type bonds between the amino group and keto functions of the DAC (-HC=N-). The modification was achieved in aqueous medium under mild reaction conditions. Different treatments cause different levels of hydrolysis of the organosilane compound, which resulted in diverse condensed silica networks in the modified dialdehyde cellulose structure.

Mikto-Brush-Arm Star Polymers via Cross-Linking of Dissimilar Bottlebrushes: Synthesis and Solution Morphologies

2017 ◽  
Vol 6 (9) ◽  
pp. 963-968 ◽  
Author(s):  
Yoshiki Shibuya ◽  
Hung V.-T. Nguyen ◽  
Jeremiah A. Johnson
Keyword(s):  
Star Polymers ◽  
Cross Linking

Removal of U(VI) from aqueous media by hydrothermal cross-linking chitosan with phosphate group

2016 ◽  
Vol 309 (3) ◽  
pp. 1217-1226 ◽  
Author(s):  
Zhi-min Dong ◽  
Yan-fang Qiu ◽  
Ying Dai ◽  
Xiao-hong Cao ◽  
Lin Wang ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Phosphate Group ◽  
Cross Linking
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