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Triblock Copolymers

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https://www.readbyqxmd.com/read/30544769/supramolecular-modification-of-abc-triblock-terpolymers-in-confinement-assembly
#1
Giada Quintieri, Marco Saccone, Matthias Spengler, Michael Giese, André H Gröschel
The self-assembly of AB diblock copolymers in three-dimensional (3D) soft confinement of nanoemulsions has recently become an attractive bottom up route to prepare colloids with controlled inner morphologies. In that regard, ABC triblock terpolymers show a more complex morphological behavior and could thus give access to extensive libraries of multicompartment microparticles. However, knowledge about their self-assembly in confinement is very limited thus far. Here, we investigated the confinement assembly of polystyrene- block -poly(4-vinylpyridine)- block -poly( tert -butyl methacrylate) (PS- b -P4VP- b -PT or SVT) triblock terpolymers in nanoemulsion droplets...
December 10, 2018: Nanomaterials
https://www.readbyqxmd.com/read/30543209/viscoelastic-change-of-block-copolymer-ion-gels-in-a-photo-switchable-azobenzene-ionic-liquid-triggered-by-light
#2
Caihong Wang, Kei Hashimoto, Ryota Tamate, Hisashi Kokubo, Ken Morishima, Xiang Li, Mitsuhiro Shibayama, Fengniu Lu, Takashi Nakanishi, Masayoshi Watanabe
A photo-switchable ionic liquid solvent bearing an azobenzene moiety induced a viscoelastic change of block copolymer ion gels by light. ABA triblock copolymers having poly(phenethyl methacrylate) and poly(benzyl methacrylate) as A blocks exhibited opposite photoinduced rheological responses although they had only a tiny structural difference in the alkyl chain length.
December 13, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/30529667/pluronics-intelligent-building-units-for-targeted-cancer-therapy-and-molecular-imaging
#3
Nisar Ul Khaliq, Dal Yong Park, Byeong Min Yun, Da Hye Yang, Yong Woo Jung, Jae Hong Seo, Chang Soon Hwang, Soon Hong Yuk
Pluronics are triblock copolymers, in which two hydrophilic poly (ethylene oxide) (PEO) blocks are connected via a hydrophobic poly propylene oxide (PPO) block. Because of their low molecular weight and high content of PEO, Pluronics have demonstrated the micellization phenomenon, which is dependent on temperature and/or concentration. With an understanding of micellization phenomenon in more detail, information on the morphology, micelle core radius, aggregation behavior with critical micelle concentration (CMC) and critical micelle temperature (CMT) and so on has been revealed...
December 6, 2018: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/30525711/rose-bitumen-mesoscopic-model-of-bitumen-and-bituminous-mixtures
#4
Claire A Lemarchand, Michael L Greenfield, Jeppe C Dyre, J S Hansen
We present a mesoscopic model for bitumen and bituminous mixtures. The model, which is based on dissipative particle dynamics, consists of different dynamical entities that represent the different characteristic time scales. Through the stress relaxation function, the mechanical properties of the model are investigated. For pure bitumen, the viscosity features super-Arrhenius behavior in the low-temperature regime in agreement with experimental data. The frequency-dependent viscoelastic properties show purely viscous behavior at low frequencies with increasing elasticity and hardening at higher frequencies, as expected...
December 7, 2018: Journal of Chemical Physics
https://www.readbyqxmd.com/read/30521830/hydrogels-with-prolonged-release-of-therapeutic-antibody-block-junction-chemistry-modification-of-aba-copolymers-provides-superior-anticancer-efficacy
#5
Chuan Yang, Ashlynn Lee, Shujun Gao, Shaoqiong Liu, James L Hedrick, Yi Yan Yang
In this study, we report a new series of vitamin E-functionalized 'ABA' triblock copolymers with carbamate block junction, which can form hydrogen-bonds. These polymers were synthesized via solvent- and catalyst-free nucleophilic addition between PEG-diamine and vitamin E-functionalized cyclic carbonate. The catalyst-free synthesis enabled an easy purification step and recycling of excess monomers. The polymers formed hydrogels through self-assembly by simply dissolving in aqueous solution. The hydrogel stiffness was easily tuned by varying polymer concentration, PEG molecular weight and number of vitamin E molecules...
December 4, 2018: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/30507172/self-sorting-of-amphiphilic-copolymers-for-self-assembly-materials-in-water-polymer-can-recognize-itself
#6
Shota Imai, Mikihito Takenaka, Mitsuo Sawamoto, Takaya Terashima
Amphiphilic random copolymers bearing hydrophilic poly(ethylene glycol) (PEG) and hydrophobic alkyl pendants showed dynamic self-sorting behavior, i.e., self-recognition, under competitive conditions in aqueous media. The self-sorting universally takes place not only in water but also in hydrogels and on the material surfaces, according to encoded information originating from the primary structure of composition and pendants. Binary blends of the copolymers with different composition and/or alkyl pendants readily induced com-position and/or alkyl pendant-dependent self-sorting to simultaneously provide discrete and size-controlled micelles with hydrophobic cores...
December 3, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/30500176/preparing-semiconducting-nanoribbons-with-tunable-length-and-width-via-crystallization-driven-self-assembly-of-a-simple-conjugated-homopolymer
#7
Inho Choi, Sanghee Yang, Tae-Lim Choi
Precise control of width and length of one-dimensional (1D) semiconducting nanostructures has attracted much attention owing to its potential for optoelectronic applications. However, regulating both their length and width using conjugated polymers or even block copolymers is a huge challenge. To solve this problem, we synthesized a unique conjugated polyacetylene homopolymer by living cyclopolymerization, which spontaneously formed 1D nanoribbons via in situ nanoparticlization. Interestingly, their widths could be controlled from 8 to 41 nm, which were directly proportional to their degree of polymerization...
November 30, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/30498349/ph-responsive-hybrid-nanoparticle-with-enhanced-dissociation-characteristic-for-sirna-delivery
#8
Menghao Shi, Xiufeng Zhao, Jiulong Zhang, Shuang Pan, Chunrong Yang, Ying Wei, Haiyang Hu, Mingxi Qiao, Dawei Chen, Xiuli Zhao
Introduction: Specific polo-like kinase (PLK1) silencing with small interface RNA (siRNA) may be an effective approach for PLK1-overexpressed lung cancer. However, low siRNA concentration into cytoplasm of tumor tissue severely limits its application. Materials and methods: In this study, a novel triblock copolymer methoxy poly(ethylene glycol)-poly(histidine)-poly(sulfadimethoxine) (mPEG-PHis-PSD, shorten as PHD) was synthesized and used to construct novel nonviral gene vector with cationic liposomes...
2018: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/30481535/effect-of-cellulose-nanocrystals-on-the-performance-of-drug-loaded-in-situ-gelling-thermo-responsive-ophthalmic-formulations
#9
Jonathan Tersur Orasugh, Gunjan Sarkar, Nayan Ranjan Saha, Beauty Das, Amartya Bhattacharyya, Sreyasi Das, Roshnara Mishra, Indranil Roy, Atiskumar Chattoapadhyay, Swapan Kumar Ghosh, Dipankar Chattopadhyay
Triblock poloxamer copolymer (PM) has been extensively utilized to deliver various ophthalmic pharmaceutical compounds. The aim of efficient ophthalmic drug delivery strategy is to attain the longer precorneal resident time and good bioavailability of drugs. In this pursuit, the influence of cellulose nanocrystals (CNC) on the in situ gelation behavior of PM and in vitro release of pilocarpine hydrochloride from the nanocomposites formulations was studied. The critical concentration of gelation of PM being 18% (wt/v) was dropped to 16...
November 24, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/30471612/effect-of-triblock-copolymer-surfactant-composition-on-flow-induced-phase-inversion-emulsification-in-a-tapered-channel
#10
Gang Duan, Ankit Kumar, Shigeng Li, Chieh-Min Cheng, Daeyeon Lee
HYPOTHESIS: Phase inversion emulsification (PIE) is a process that inverts the dispersed and continuous phases of an emulsion and is useful for preparing emulsions that are challenging to produce using conventional techniques. A recent work has shown that PIE can be induced by flowing an emulsion through a tapered channel. Although prior studies have shown that flow-induced PIE (FIPIE) is influenced by the flow conditions and wetting properties of the channel surface, little is known about the effect of surfactant structure on FIPIE...
November 8, 2018: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/30470518/evaporation-induced-self-assembly-synthesis-of-nanostructured-alumina-based-mixed-metal-oxides-with-tailored-porosity
#11
Alexandre Amormino S Gonçalves, Mietek Jaroniec
The one-pot synthesis of nanostructured ternary mixed oxides is challenging due to the heterogeneous nature of the hydrolysis and condensation processes of all metal oxide precursors. In addition, the solvents and additives used can affect these processes too. Herein, we report the effect of different solvents (ethanol, 1- and 2-propanol, or butanol) and additives (citric acid or 1,3,5-triisopropylbenzene) used on the formation of binary and ternary alumina-based oxides, NiO-Al2 O3 , NiO-TiO2 -Al2 O3 , and NiO-ZrO2 -Al2 O3 in the presence of triblock copolymer Pluronic P123 used as a soft template...
November 14, 2018: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/30455583/-in-situ-synthesis-of-polyurethane-scaffolds-with-tunable-properties-by-controlled-crosslinking-of-tri-block-copolymer-and-polycaprolactone-triol-for-tissue-regeneration
#12
Hao-Yang Mi, Xin Jing, Galip Yilmaz, Breanna S Hagerty, Eduardo Enriquez, Lih-Sheng Turng
Mimicking the mechanical properties of native tissues is a critical criterion for an ideal tissue engineering scaffold. However, most biodegradable synthetic materials, including polyester-based polyurethanes (PUs), consist of rigid polyester chains and have high crystallinity. They typically lack the elasticity of most human tissues. In this study, a new type of biodegradable PU with excellent elasticity was synthesized based on the controlled crosslinking of poly(ester ether) triblock copolymer diols and polycaprolactone (PCL) triols using urethane linkages...
September 15, 2018: Chemical Engineering Journal
https://www.readbyqxmd.com/read/30453510/development-of-alumina%C3%A2-mesoporous-organosilica-hybrid-materials-for-carbon-dioxide-adsorption-at-25-%C3%A2-c
#13
Chamila Gunathilake, Rohan S Dassanayake, Chandrakantha S Kalpage, Mietek Jaroniec
Two series of alumina (Al₂O₃)⁻mesoporous organosilica (Al⁻MO) hybrid materials were synthesized using the co-condensation method in the presence of Pluronic 123 triblock copolymer. The first series of Al⁻MO samples was prepared using aluminum nitrate nanahydrate (Al⁻NN) and aluminum isopropoxide (Al⁻IP) as alumina precursors, and organosilanes with three different bridging groups, namely tris[3-(trimethoxysilyl)propyl]isocyanurate, 1,4-bis(triethoxysilyl)benzene, and bis(triethoxysilyl)ethane...
November 16, 2018: Materials
https://www.readbyqxmd.com/read/30444112/synthesis-and-formation-mechanism-of-all-organic-block-copolymer-directed-templating-of-laser-induced-crystalline-silicon-nanostructures
#14
Kwan W Tan, Jörg G Werner, Matthew Goodman, Ha Seong Kim, Byungki Jung, Hiroaki Sai, Paul V Braun, Michael O Thompson, Ulrich Wiesner
This report describes the generation of three-dimensional (3D) crystalline silicon continuous network nanostructures by coupling all-organic block copolymer self-assembly-directed resin templates with low temperature silicon chemical vapor deposition and pulsed excimer laser annealing. Organic 3D mesoporous continuous network resin templates were synthesized from the all-organic self-assembly of an ABC triblock terpolymer and resorcinol-formaldehyde resols. Nanosecond pulsed excimer laser irradiation induced the transient melt transformation of amorphous silicon precursors backfilled in the organic template into complimentary 3D mesoporous crystalline silicon nanostructures with high pattern fidelity...
November 16, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/30441905/effect-of-composition-and-molecular-structure-of-poly-l-lactic-acid-poly-ethylene-oxide-block-copolymers-on-micellar-morphology-in-aqueous-solution
#15
Ekaterina Razuvaeva, Alevtina Kulebyakina, Dmitry R Streltsov, Artem V Bakirov, Roman Kamyshinsky, Nikita Miсhailovich Kuznetsov, Sergei N Chvalun, Eleonora V Shtykova
Effect of the hydrophobic block length in di- (PLLAx-b-PEO113, x = 64, 166, 418) and triblock (PLLAy-b-PEO91-b-PLLAy, y = 30, 52, 120) copolymers of L-lactic acid and ethylene oxide on the structure of micelles prepared by dialysis was studied by wide- and small-angle X-ray scattering in diluted aqueous solution, dynamic light scattering, transmission electron microscopy, atomic force microscopy and force spectroscopy. It was found that the size of the crystalline PLLA core is weakly dependent on the PLLA block length...
November 15, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/30441879/thermoplastic-pcl-b-peg-b-pcl-and-hdi-polyurethanes-for-extrusion-based-3d-printing-of-tough-hydrogels
#16
Aysun Güney, Christina Gardiner, Andrew McCormack, Jos Malda, Dirk W Grijpma
Novel tough hydrogel materials are required for 3D-printing applications. Here, a series of thermoplastic polyurethanes (TPUs) based on poly(ɛ-caprolactone)- b -poly(ethylene glycol)- b -poly(ɛ-caprolactone) (PCL- b -PEG- b -PCL) triblock copolymers and hexamethylene diisocyanate (HDI) were developed with PEG contents varying between 30 and 70 mol%. These showed excellent mechanical properties not only when dry, but also when hydrated: TPUs prepared from PCL- b -PEG- b -PCL with PEG of Mn 6 kg/mol (PCL₇-PEG₆-PCL₇) took up 122 wt...
November 14, 2018: Bioengineering
https://www.readbyqxmd.com/read/30428672/structural-tunability-of-multicompartment-micelles-as-a-function-of-lipophilic-fluorophilic-block-length-ratio
#17
Connor P Callaway, Nicholas Bond, Kayla Hendrickson, Seung Min Lee, Seung Soon Jang
Structural variation in multicompartment micelles consisting of lipophilic-hydrophilic-fluorophilic (hereafter referred to as BAC) triblock copolymers is investigated using the dissipative particle dynamics simulation method. It is demonstrated from our results that the structure of BAC multicompartment micelles is effectively tuned as a function of the lipophilic-fluorophilic ratio parameter, here termed [Formula: see text], of the constituent linear triblock copolymers. In particular, a morphological deviation from onion-like ABC micelles arises in BAC micelle systems as [Formula: see text] increases...
November 28, 2018: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/30428623/polypeptides-micelles-composed-of-methoxy-poly-ethylene-glycol-poly-l-glutamic-acid-poly-l-phenylalanine-triblock-polymer-for-sustained-drug-delivery
#18
Xingzheng Liu, Rongrong Fan, Boting Lu, Yuan Le
Methoxy-poly(ethylene glycol)-poly(l-glutamic acid)-poly(l-phenylalanine) triblock polymers with different architecture were synthesized as drug carrier to obtain sustained and controlled release by tuning the composition. These triblock polymers were prepared by ring opening polymerization and poly(ethylene glycol) was used as an initiator. Polymerization was confirmed by ¹H NMR, FT-IR and gel penetration chromatography. The polymers can self-assemble to form micelles in aqueous medium and their critical micelle concentrations values were examined...
November 13, 2018: Pharmaceutics
https://www.readbyqxmd.com/read/30426748/flexible-sis-hkust-1-mixed-matrix-composites-as-protective-barriers-against-chemical-warfare-agent-simulants
#19
Gregory W Peterson, Matthew A Browe, Erin Durke, Thomas H Epps Iii
We fabricated and demonstrated, for the first time, metal-organic framework (MOF) - polymer mixed matrix composites (MMCs) as effective, low burden barriers against chemical warfare agent (CWA) simulants. We incorporated the MOF HKUST-1 into elastomeric triblock copolymers of polystyrene-block-polyisoprene-block-polystyrene (SIS) for use as semipermeable barrier against the CWA simulant 2-chloroethyl ethyl sulfide (CEES). MMCs containing up to 50 wt% HKUST-1 were cast and evaluated for CEES permeation, moisture vapor transport rate (MVTR), and mechanical properties, such as elastic modulus and percent elongation...
November 14, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/30424438/unexpected-phase-behavior-of-pluronic-polymer-organic-derivative-mixtures-depending-on-temperature-in-aqueous-solution
#20
Jong-Dae Jang, Eunhye Kim, Min-Jae Lee, Young-Soo Han, Joona Bang, Tae-Hwan Kim
The phase behavior of amphiphilic Pluronic block copolymers in aqueous solution is of importance for a broad spectrum of practical applications but has not been fully exploited yet. Here, the phase behavior of the mixture of the Pluronic P65 and P105 triblock copolymer, (which have the same composition of PEO and PPO but the different molecular weight) and organic derivative, 5-methyl salicylic acid (5mS), in aqueous solution has been investigated by using small angle neutron scattering (SANS). According to the temperature and the 5mS concentration, SANS measurements showed that the P65-5mS mixtures sequentially transform into a random coil, sphere, vesicle, cylinder, and vesicle again, while the P105-5mS mixtures form spherical particles with two different sizes without any topological phase transition...
October 5, 2018: Micromachines
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