scholarly journals A mild and quantitative route towards well-defined strong anionic/hydrophobic diblock copolymers: synthesis and aqueous self-assembly

2019 ◽  
Vol 10 (45) ◽  
pp. 6109-6115
Author(s):  
Anton H. Hofman ◽  
Remco Fokkink ◽  
Marleen Kamperman

Well-defined hydrophobic/strong anionic diblock copolymers were synthesized through a protected hydrophobic intermediate. Their self-assembly in aqueous solution was subsequently studied.

Polymer ◽  
2015 ◽  
Vol 57 ◽  
pp. 125-131 ◽  
Author(s):  
BiYun Mai ◽  
Ran Liu ◽  
ZhiYun Li ◽  
Shuo Feng ◽  
Qing Wu ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 338
Author(s):  
Martha Kafetzi ◽  
Stergios Pispas

In this work, the synthesis and the aqueous solution self-assembly behavior of novel partially hydrophobically modified poly(2-(dimethylamino) ethyl methacrylate)-b-poly(oligo(ethylelene glycol) methyl ether methacrylatetabel) pH and temperature responsive random diblock copolymers (P(DMAEMA-co-Q6/12DMAEMA)-b-POEGMA), are reported. The chemical modifications were accomplished via quaternization with 1-iodohexane (Q6) and 1-iodododecane (Q12) and confirmed by 1H-NMR spectroscopy. The successful synthesis of PDMAEMA-b-POEGMA precursor block copolymers was conducted by RAFT polymerization. The partial chemical modification of the diblocks resulted in the permanent attachment of long alkyl chains on the amine groups of the PDMAEMA block and the presence of tertiary and quaternary amines randomly distributed within the PDMAEMA block. Light scattering techniques confirmed that the increased hydrophobic character results in the formation of nanoaggregates of high mass and tunable pH and temperature response. The characteristics of the aggregates are also affected by the aqueous solution preparation protocol, the nature of the quaternizing agent and the quaternization degree. The incorporation of long alkyl chains allowed the encapsulation of indomethacin within the amphiphilic diblock copolymer aggregates. Nanostructures of increased size were detected due to the encapsulation of indomethacin into the interior of the hydrophobic domains. Drug release studies demonstrated that almost 50% of the encapsulated drug can be released on demand by aid of ultrasonication.


2016 ◽  
Vol 69 (7) ◽  
pp. 741 ◽  
Author(s):  
Chao Chen ◽  
Zeyun Xiao ◽  
Luke A. Connal

The aqueous solution self-assembly of a series of poly(2-vinyl pyridine)-block-poly(dimethylsiloxane) (P2VP-b-PDMS) diblock copolymers is reported. The particles show a phase separated interior morphology which can be tuned from onion-like sphere to axially stacked lamella with dimensions in the nanoscale. The key to this transition is the control of the interfacial properties using a mixture of two surfactants with preferential wetting to the respective blocks (P2VP or PDMS). Influence of block weights on particle morphology was investigated with results showing that the volume fraction of PDMS plays a crucial role in self-assembly, and a non-conventional structure of a prolate spheroid nanoparticle with a unique phase separated interior morphology can be synthesised.


Author(s):  
Krishna Sailaja A ◽  
Amareshwar P

In order to see the functionality and toxicity of nanoparticles in various food and drug applications, it is important to establish procedures to prepare nanoparticles of a controlled size. Desolvation is a thermodynamically driven self-assembly process for polymeric materials. In this study, we prepared BSA nanoparticles using the desolvation technique using acetone as desolvating agent. Acetone was added intermittently into 1% BSA solution at different pH under stirring at 700 rpm. Amount of acetone added, intermittent timeline of acetone addition, and pH of solution were considered as process parameters to be optimized. The effect of the process parameters on size of the nanoparticles was studied. The results indicated that the size control of BSA nanoparticles was achieved by adding acetone intermittently. The standard deviation of average size of BSA nanoparticles at each preparation condition was minimized by adding acetone intermittently. The intermittent addition in polymeric aqueous solution can be useful for size control for food or drug applications.  


2012 ◽  
Vol 9 (1) ◽  
pp. 22-25
Author(s):  
S.V. Amel’kin ◽  
D.Ye. Igoshin

A self-assembly model for porous hydrate structures is proposed, which takes into account the sequence of basic physical processes: hydrate growth on the surface of the aqueous solution, formation of islet structure, capillary flow, separation and transfer of secondary crystallization nuclei to the meniscus. The model was studied within the cellular automata method. A good correspondence between the results of the simulation and the experimental data is obtained.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3598
Author(s):  
Nirmal K. Shee ◽  
Hee-Joon Kim

A series of porphyrin triads (1–6), based on the reaction of trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP) with six different phenoxy Zn(II)-porphyrins (ZnLn), was synthesized. The cooperative metal–ligand coordination of 3-pyridyl nitrogens in the SnP with the phenoxy Zn(II)-porphyrins, followed by the self-assembly process, leads to the formation of nanostructures. The red-shifts and remarkable broadening of the absorption bands in the UV–vis spectra for the triads in CHCl3 indicate that nanoaggregates may be produced in the self-assembly process of these triads. The emission intensities of the triads were also significantly reduced due to the aggregation. Microscopic analyses of the nanostructures of the triads reveal differences due to the different substituents on the axial Zn(II)-porphyrin moieties. All these nanomaterials exhibited efficient photocatalytic performances in the degradation of rhodamine B (RhB) dye under visible light irradiation, and the degradation efficiencies of RhB in aqueous solution were observed to be 72~95% within 4 h. In addition, the efficiency of the catalyst was not impaired, showing excellent recyclability even after being applied for the degradation of RhB in up to five cycles.


Author(s):  
Xiaofeng Huang ◽  
Qiulin Deng ◽  
Xingzhang Wang ◽  
Hongquan Deng ◽  
Tinghong Zhang ◽  
...  

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