Supramolecular polymerization induced self-assembly into micelle and vesicle via acid–base controlled formation of fluorescence responsive supramolecular hyperbranched polymers

2016 ◽  
Vol 7 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Lijie Li ◽  
Xiaorui Zheng ◽  
Bingran Yu ◽  
Lipeng He ◽  
Jing Zhang ◽  
...  

Micellar and vesicular aggregates were achieved in situ by supramolecular polymerization of π-conjugated AB2 monomers with dibenzo-24-crown-8 and dibenzylammonium groups.

Nanoscale ◽  
2019 ◽  
Vol 11 (29) ◽  
pp. 14060-14069 ◽  
Author(s):  
Boyce S. Chang ◽  
Brijith Thomas ◽  
Jiahao Chen ◽  
Ian D. Tevis ◽  
Paul Karanja ◽  
...  

Coordination polymers are ideal synthons for high aspect ratio nanomaterials. Using conjugate acid-base pairs, liquid metals are etched and chelated in situ. Solubility-driven polymerization, precipitation, and self-assembly gives tunable structures.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans

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.


2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.


2016 ◽  
Vol 9 (2) ◽  
pp. 187-197
Author(s):  
Sugihartono Sugihartono

Skinswaste at pre-tanning operations can be processed into food grade gelatin. The degradation of collagen using acid, base, or enzymes produced gelatin. Pickle skins is skins that acidified, the results of the final phase of the pre-tanning operations. The addition of salt on the skin makes the skins pickle not swollen, produced a wide space between collagen fibers and collagen can not be degraded. Thereby directly extract pickle skins or waste will not be obtained gelatin.This study discussed the processing of food gelatin type A pickle skins through the utilization of waste acid it contains. The discussion includes the components of animal skins, pre-tanning waste, acidification of skins, processing gelatin and gelatin from skins picklewaste and usefulness for the food industry. Salt hydrate collagen fibers in the skin pickle including waste can be separated by washing, to a certain extent still acidic skins waste. The remaining acid on the skins pickle waste can be utilized to hydrolyze collagen into gelatin. The resulting gelatin is gelatin type A, that can be used for food industry.ABSTRAKKulit limbah pada operasi pra-penyamakan dapat diolah menjadi gelatin pangan. Pemecahan kolagen menggunakan asam, basa, atau enzim dihasilkan gelatin. Kulit pikel merupakan kulit yang diasamkan, hasil dari tahap akhir operasi pra-penyamakan. Penambahan garam pada kulit pikel menjadikan kulit tidak bengkak, menghasilkan ruang lebar diantara serat kolagen dan menjadikan kolagen tidak dapat terdegradasi. Hal ini berarti ekstrak secara langsung kulit pikel atau limbahnya tidak akan diperoleh gelatin. Dalam kajian ini dibahas pengolahan gelatin pangan tipe A dari kulit pikel limbah melalui pendayagunaan asam yang dikandungnya. Bahasan mencakup komponen kulit hewan, limbah pra-penyamakan, pengasaman kulit, pengolahan gelatin, dan pengolahan gelatin dari kulit pikel limbah melalui pendayagunaan asam yang dikandungnya serta kegunaannya untuk industri pangan. Garam yang menghidrasi serat kolagen pada kulit pikel termasuk limbahnya dapat dipisahkan dengan cara pencucian, sampai batas tertentu kulit limbah masih bersifat asam. Asam yang tersisa pada kulit pikel limbah tersebut dapat didayagunakan untuk menghidrolisis kolagen menjadi gelatin. Gelatin yang dihasilkan adalah gelatin tipe A, dapat digunakan untuk keperluan industri pangan. Kata kunci : Kulit pikel limbah, gelatin, pengasaman, pangan.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 904
Author(s):  
Irin Tanaudommongkon ◽  
Asama Tanaudommongkon ◽  
Xiaowei Dong

Most antiretroviral medications for human immunodeficiency virus treatment and prevention require high levels of patient adherence, such that medications need to be administered daily without missing doses. Here, a long-acting subcutaneous injection of lopinavir (LPV) in combination with ritonavir (RTV) using in situ self-assembly nanoparticles (ISNPs) was developed to potentially overcome adherence barriers. The ISNP approach can improve the pharmacokinetic profiles of the drugs. The ISNPs were characterized in terms of particle size, drug entrapment efficiency, drug loading, in vitro release study, and in vivo pharmacokinetic study. LPV/RTV ISNPs were 167.8 nm in size, with a polydispersity index of less than 0.35. The entrapment efficiency was over 98% for both LPV and RTV, with drug loadings of 25% LPV and 6.3% RTV. A slow release rate of LPV was observed at about 20% on day 5, followed by a sustained release beyond 14 days. RTV released faster than LPV in the first 5 days and slower than LPV thereafter. LPV trough concentration remained above 160 ng/mL and RTV trough concentration was above 50 ng/mL after 6 days with one subcutaneous injection. Overall, the ISNP-based LPV/RTV injection showed sustained release profiles in both in vitro and in vivo studies.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Chunzheng Lv ◽  
Lirong He ◽  
Jiahong Tang ◽  
Feng Yang ◽  
Chuhong Zhang

AbstractAs an important photoconductive hybrid material, perylene/ZnO has attracted tremendous attention for photovoltaic-related applications, but generally faces a great challenge to design molecular level dispersed perylenes/ZnO nanohybrids due to easy phase separation between perylenes and ZnO nanocrystals. In this work, we reported an in-situ reaction method to prepare molecular level dispersed H-aggregates of perylene bisimide/ZnO nanorod hybrids. Surface photovoltage and electric field-induced surface photovoltage spectrum show that the photovoltage intensities of nanorod hybrids increased dramatically for 100 times compared with that of pristine perylene bisimide. The enhancement of photovoltage intensities resulting from two aspects: (1) the photo-generated electrons transfer from perylene bisimide to ZnO nanorod due to the electric field formed on the interface of perylene bisimide/ZnO; (2) the H-aggregates of perylene bisimide in ZnO nanorod composites, which is beneficial for photo-generated charge separation and transportation. The introduction of ordered self-assembly thiol-functionalized perylene-3,4,9,10-tetracarboxylic diimide (T-PTCDI)/ ZnO nanorod composites induces a significant improvement in incident photo-to-electron conversion efficiency. This work provides a novel mentality to boost photo-induced charge transfer efficiency, which brings new inspiration for the preparation of the highly efficient solar cell.


Author(s):  
Shotaro Tada ◽  
Norifumi Asakuma ◽  
Shiori Ando ◽  
Toru Asaka ◽  
Yusuke Daiko ◽  
...  

This paper reports on the relationship between the H2 chemisorption properties and reversible structural reorientation of the possible active site around Al formed in-situ within polymer-derived ceramics (PDCs) based on...


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