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https://www.readbyqxmd.com/read/30082594/poss-nanofiller-induced-enhancement-of-the-thermomechanical-properties-in-a-fluoroelastomer-terpolymer
#1
Daphné Berthier, Marie-Pierre Deffarges, Nicolas Berton, Mathieu Venin, Florian Lacroix, Bruno Schmaltz, Yohan Tendron, Eric Pestel, François Tran-Van, Stéphane Méo
The present study reports on the use of three types of polyhedral oligomeric silsesquioxanes (POSS) nanoparticles with various organic substituents as fillers in a fluoroelastomer (FKM). A series of/POSS elastomer composite thin films is prepared. Microstructural SEM/TEM (scanning electron microscopy/transmission electron microscopy) imaging reveals a dispersion state allowing the presence of micron-sized domains. The influence of POSS content is studied in order to optimize thermal stability and mechanical properties of the composite thin films...
August 6, 2018: Materials
https://www.readbyqxmd.com/read/30074601/hierarchically-ordered-structures-of-disk-cube-triads-containing-hexa-peri-hexabenzocoronene-and-polyhedral-oligomeric-silsesquioxane
#2
Wei Zhang, Kehua Gu, Pingping Hou, Xiaolin Lyu, Hongbing Pan, Zhihao Shen, Xing-He Fan
Obtaining nanoscale-ordered structures is important for the development of nanotechnology. We designed and synthesized a series of disk-cube triads containing one hexa-peri-hexabenzocoronene (HBC) and two polyhedral oligomeric silsesquioxane (POSS) moieties, HBC-2POSS. The two POSS units were linked via ester or amide bonds. With the amide linkage used, the hydrogen bonding that was introduced affected the balance between the π-π interaction of HBC cores and crystallization interaction of POSS units. Hierarchically ordered structures were obtained from HBC-2POSS triads owing to the synergistic effect of multiple secondary interactions: π-π interaction, hydrogen bonding, and crystallization interaction...
August 3, 2018: Soft Matter
https://www.readbyqxmd.com/read/30055448/fabrication-of-si-and-ge-nanoarrays-through-graphoepitaxial-directed-hardmask-block-copolymer-self-assembly
#3
Anushka S Gangnaik, Tandra Ghoshal, Yordan M Georgiev, Michael A Morris, Justin D Holmes
Films of self assembled diblock copolymers (BCPs) have attracted significant attention for generating semiconductor nanoarrays of sizes below 100 nm through a simple low cost approach for device fabrication. A challenging abstract is controlling microdomain orientation and ordering dictated by complex interplay of surface energies, polymer-solvent interactions and domain spacing. In context, microphase separated poly (styrene-b-ethylene oxide) (PS-b-PEO) thin films is illustrated to fabricate nanopatterns on silicon and germanium materials trenches...
June 30, 2018: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/30031301/detailed-characterization-of-poss-poly-ethylene-glycol-interaction-with-model-phospholipid-membrane-at-the-air-water-interface
#4
Marta Skrzypiec, Krystyna Prochaska
Polyhedral oligomeric silsesquioxanes (POSS) derivatives have been receiving remarkable attention due to their potential biomedical application and therefore understanding molecular mechanism of their interaction with cell membranes should be studied at molecular level. Here we investigate the binary mixture of an open silsesquioxane cage POSS-poly(ethylene glycol) (POSS-PEG) and 1,2-myristoyl-sn-glycero-3-phosphoethanolamine (DMPE) as a representative of phospholipid located in biological membranes. The surface pressure-area and surface potential-area compression isotherms, as well as Brewster angle microscopy and interfacial shear rheology were used to study monolayers at the air/water interface...
July 18, 2018: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/30022535/mechanically-robust-atomic-oxygen-resistant-coatings-capable-of-autonomously-healing-damage-in-low-earth-orbit-space-environment
#5
Xiaohan Wang, Yixuan Li, Yuhai Qian, Hong Qi, Jian Li, Junqi Sun
Polymeric materials used in spacecraft require to be protected with an atomic oxygen (AO)-resistant layer because AO can degrade these polymers when spacecraft serves in low earth orbit (LEO) environment. However, mechanical damage on AO-resistant coatings can expose the underlying polymers to AO erosion, shortening their service life. In this study, the fabrication of durable AO-resistant coatings that are capable of autonomously healing mechanical damage under LEO environment is presented. The self-healing AO-resistant coatings are comprised of 2-ureido-4[1H]-pyrimidinone (UPy)-functionalized polyhedral oligomeric silsesquioxane (POSS) (denoted as UPy-POSS) that forms hydrogen-bonded three-dimensional supramolecular polymers...
July 18, 2018: Advanced Materials
https://www.readbyqxmd.com/read/30015115/single-step-synthesis-of-janus-nano-composite-membranes-by-atmospheric-aerosol-plasma-polymerization-for-solvents-separation
#6
Xiao Chen, Chiara Lo Porto, Zhiqiang Chen, Andrea Merenda, François-Marie Allioux, Riccardo d'Agostino, Kevin Magniez, Xiujuan J Dai, Fabio Palumbo, Ludovic F Dumée
Solvent permeation across membranes is limited due to physical resistance to diffusion from the selective layer within the membrane and to plasticizing effects generated by the solvent molecules onto the polymeric macromolecular matrix. Nano-composite thin film membranes provide promising routes to generate controlled microstructural separation materials with higher selectivities and permeabilities. Here, the fabrication of nano-composite based on octamethyl-polyhedral oligomeric silsesquioxane - hexamethyldisiloxane thin film membranes is demonstrated by aerosol assisted atmospheric plasma deposition onto pre-formed nano-porous membrane supports for the first time...
July 13, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/30011916/modification-of-polyhedral-oligomeric-silsesquioxanes-poss-molecules-by-ruthenium-catalyzed-cross-metathesis
#7
Justyna Czaban-Jóźwiak, Łukasz Woźniak, Artur Ulikowski, Katarzyna Kwiecińska, Adam A Rajkiewicz, Karol Grela
The scope of ruthenium (Ru)-catalyzed cross metathesis (CM) of allyl-decorated polyhedral oligomeric silsesquioxanes (POSS) was explored. A variety of different commercial and non-commercial ruthenium complexes were tested to determine that the nitro-activated Ru catalyst is optimal for this transformation. The reported transformation was used to prepare selected hybrid steroid-POSS compounds.
July 14, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29998277/nano-confinement-of-block-copolymers-in-high-accuracy-topographical-guiding-patterns-modelling-the-emergence-of-defectivity-due-to-incommensurability
#8
Steven Gottlieb, Dimitrios Kazazis, Iacopo Mochi, Laura Evangelio, Marta Fernández-Regúlez, Yasin Ekinci, Francesc Perez-Murano
Extreme ultraviolet interference lithography (EUV-IL) is used to manufacture topographical guiding patterns to direct the self-assembly of block copolymers. High-accuracy silicon oxide-like patterns with trenches ranging from 68 nm to 117 nm width are fabricated by exposing a hydrogen silsesquioxane (HSQ) resist layer using EUV-IL. We investigate how the accuracy, the low line width roughness and the low line edge roughness of the resulting patterns allow achieving DSA line/space patterns of a PS-b-PMMA (polystyrene-block-poly methyl methacrylate) block copolymer of 11 nm half-pitch with low defectivity...
July 12, 2018: Soft Matter
https://www.readbyqxmd.com/read/29939748/synthesis-and-porous-sio-2-nanofilm-formation-of-the-silsesquioxane-containing-amphiphilic-block-copolymer
#9
Yuya Ishizaki, Shunsuke Yamamoto, Tokuji Miyashita, Masaya Mitsuishi
We describe the synthesis, Langmuir-Blodgett (LB) film formation, and photo-oxidation of an organic-inorganic hybrid block copolymer consisting of N-dodecyl acrylamide (DDA) and silsesquioxane (SQ) comonomers [p(DDA/SQ26)- b-pDDA]. The copolymer was synthesized by reversible addition fragmentation chain transfer polymerization of DDA and SQ. Higher monolayer stability at the air-water interface was confirmed for p(DDA/SQ26)- b-pDDA. The p(DDA/SQ26)- b-pDDA monolayer was deposited onto solid substrates with a monolayer thickness of 2...
July 10, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29934979/ferrocene-functionalized-silsesquioxane-based-porous-polymer-for-efficient-removal-of-dyes-and-heavy-metal-ions
#10
Hongzhi Liu
A novel ferrocene-linked organic-inorganic hybrid porous polymer has been successfully prepared by Friedel-Crafts reaction of octavinylsilsesquioxane and ferrocene. The relationship of structure/property was investigated by FTIR, NMR, XRD, BET et.al. The obtained porous polymer exhibits a high surface area of 1015 m2 g-1 and a hierarchical pore structure. It could be well applied to wastewater treatment with the adsorption capacity up to 1683 mg g-1 for Congo red (CR), 1083 mg g-1 for Crystal violet (CV), 1003 mg g-1 for Rhodamine B (RB), 441 mg g-1 for Methylene blue (MB), 191 mg g-1 for Hg2+ and 328 mg g-1 for Pb2+, respectively...
June 23, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29909638/synthesis-of-novel-periodic-mesoporous-organosilicas-containing-1-4-5-8-naphthalenediimides-within-the-pore-walls-and-their-reduction-to-generate-wall-embedded-free-radicals
#11
Bruna Castanheira, Eduardo Resende Triboni, Luana Dos Santos Andrade, Fabiane de Jesus Trindade, Larissa Otubo, Antonio Carlos Silva Costa Teixeira, Mário José Politi, Thiago Branquinho de Queiroz, Sergio Brochsztain
Novel periodic mesoporous organosilicas (PMOs) containing 1,4,5,8-Naphthalenediimide (NDI) chromophores as an integral part of the pore walls were synthesized in acidic conditions, in the presence of inorganic tetraethyl orthosilicate, using triblock copolymer surfactant Pluronic P-123 as a template. The NDI precursor, the bridged silsesquioxane N, N'-bis(3-triethoxysilylpropyl)-1,4,5,8-naphthalenediimide, was synthesized by reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride with excess 3-aminopropyltriethoxysilane...
July 17, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29890680/co%C3%A2-separation-in-nanocomposite-membranes-by-the-addition-of-amidine-and-lactamide-functionalized-poss-%C3%A2-nanoparticles-into-a-pva-layer
#12
Gabriel Guerrero, May-Britt Hägg, Christian Simon, Thijs Peters, Nicolas Rival, Christelle Denonville
In this article, we studied two different types of polyhedral oligomeric silsesquioxanes (POSS® ) functionalized nanoparticles as additives for nanocomposite membranes for CO₂ separation. One with amidine functionalization (Amidino POSS® ) and the second with amine and lactamide groups functionalization (Lactamide POSS® ). Composite membranes were produced by casting a polyvinyl alcohol (PVA) layer, containing either amidine or lactamide functionalized POSS® nanoparticles, on a polysulfone (PSf) porous support...
June 8, 2018: Membranes
https://www.readbyqxmd.com/read/29882571/an-insight-into-the-amphiphobicity-and-thermal-degradation-behavior-of-pdms-based-block-copolymers-bearing-poss-and-fluorinated-units
#13
Junyan Liang, Ling He, Yanyan Zuo, Zhaoyu Chen, Tao Peng
Methacryloxypropyl-polyhedral oligomeric silsesquioxane (MAPOSS) and dodecafluoroheptyl methacrylate (DFHM) are proposed to separately block-copolymerize with polydimethylsiloxane (PDMS)-based acrylate block copolymer (PDMS-b-PMMA). The syntheses of PDMS-b-PMMA-b-PMAPOSS and PDMS-b-PMMA-b-PDFHM were executed in this manner to examine the effect of PMAPOSS and PDFHM on surface amphiphobic behavior and thermal degradation behavior. PMAPOSS and PDFHM were found to both contribute towards the improvement of static hydrophobicity...
June 27, 2018: Soft Matter
https://www.readbyqxmd.com/read/29876757/ultrafast-preparation-of-a-polyhedral-oligomeric-silsesquioxane-based-ionic-liquid-hybrid-monolith-via-photoinitiated-polymerization-and-its-application-to-capillary-electrochromatography-of-aromatic-compounds
#14
Bingyu Zhang, Xiaoyun Lei, Lijun Deng, Minsheng Li, Sicong Yao, Xiaoping Wu
An ionic liquid hybrid monolithic capillary column was prepared within 7 min via photoinitiated free-radical polymerization of an ionic liquid monomer (1-butyl-3-vinylimidazolium-bis[(trifluoromethyl)sulfonyl]imide); VBIMNTF2 ) and a methacryl substituted polyhedral oligomeric silsesquioxane (POSS-MA) acting as a cross-linker. The effects of composition of prepolymerization solution and initiation time on the porous structure and electroosmotic flow (EOF) of monolithic column were investigated. The hybrid monolith was characterized by scanning electron microscopy and FTIR...
June 6, 2018: Mikrochimica Acta
https://www.readbyqxmd.com/read/29876586/enhanced-molecular-recognition-for-imprinted-monolithic-column-containing-polyhedral-oligomeric-silsesquioxanes-by-dendritic-effect-of-mesoporous-molecular-sieve-scaffolds
#15
Fang-Fang Yang, Zai-Xuan Li, Yu-Jing Xu, Yan-Ping Huang, Zhao-Sheng Liu
The dendritic effect of nano mesoporous molecular sieve was first used to enhance molecular recognition of molecularly imprinted polymers (MIPs)-based polyhedral oligomeric silsesquioxanes (POSS). In this study, the MIPs were made using S-naproxen (S-NAP) as template molecule, 4-vinylpyridine (4-VP) as functional monomer, ethylene glycol dimethacrylate as cross-linker, 1-butyl-3-methylimidazoliumtetrafluoroborate ([BMIM]BF4 )/DMSO as binary porogens, 1-propylmethacrylate-heptaisobutyl substituted as POSS monomer, and mesoporous molecular sieve (Mobil composition of matter No...
June 7, 2018: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29870824/facile-synthesis-of-mesoporous-organosilica-nanobowls-with-bridged-silsesquioxane-framework-by-one-pot-growth-and-dissolution-mechanism
#16
Xin Du, Weike Li, Bingyang Shi, Luying Su, Xiaoyu Li, Hongwei Huang, Yongqiang Wen, Xueji Zhang
Mesoporous organosilica materials with organo-bridged silsesquioxane and novel structures have attracted great attention due to combined or enhanced properties. Here, we achieved facile synthesis of uniform well-defined mesoporous organosilica nanobowls with ethane- or ethane&thioether-bridged silsesquioxane framework by one-pot reaction. The possible formation mechanism may be attributed to be a dynamic growth, dissolution and reassembly process, including a uniform coating of ethane-bridged organosilica on the surface of mesoporous silica nanoparticles (MSNs) or mesoporous organosilica nanoparticles (MONs), gradual dissolution of MSNs or MONs core for the collapse of hollow spheres, and regrowth and reassembly of a small portion of the dissolved species...
May 30, 2018: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29866505/aptamer-based-polyhedral-oligomeric-silsesquioxane-poss-containing-hybrid-affinity-monolith-prepared-via-a-one-pot-process-for-selective-extraction-of-ochratoxin-a
#17
Yiqiong Chen, Maolin Chen, Jinxin Chi, Xia Yu, Yongxuan Chen, Xucong Lin, Zenghong Xie
A novel aptamer-based polyhedral oligomeric silsesquioxane (POSS)-containing hybrid affinity monolith has been prepared with a facile "one-pot" process simultaneously via "free radical polymerization" and "thiol-ene" click reaction, and used for on-line selective extraction and practical analysis to trace ochratoxin A (OTA). By using the ternary porogenic mixture composed of water/DMF/PEG, a homogeneous polymerization mixture with POSS chemicals, acrylate-based monomers and aptamer aqueous solution was obtained, and the copolymerization of POSS chemicals, polymer monomers and aptamer aqueous solution was systematically studied...
August 17, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29788716/porous-silsesquioxane-imine-frameworks-as-highly-efficient-adsorbents-for-cooperative-iodine-capture
#18
Mateusz Janeta, Wojciech Bury, Sławomir Szafert
The efficient capture and storage of radioactive iodine (129 I or 131 I), which can be formed during nuclear energy generation or nuclear waste storage, is of paramount importance. Herein, we present highly efficient aerogels for reversible iodine capture, namely, porous silsesquioxane-imine frameworks (PSIFs), constructed by condensation of octa(3-aminopropyl)silsesquioxane cage compound and selected multitopic aldehydes. The resulting PSIFs are permanently porous (Brunauer-Emmet-Teller surface areas up to 574 m2 /g), thermally stable, and present a combination of micro-, meso-, and macropores in their structures...
June 13, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29774615/overcome-the-conflict-between-strength-and-toughness-in-poly-lactide-nanocomposites-through-tailoring-matrix-filler-interface
#19
Yang Sun, Xiaoshan Fan, Xuehong Lu, Chaobin He
Strength and toughness are the two most important prerequisites for structural applications. Unfortunately, these two properties are often in conflict in materials. Here, an effective and yet practical strategy is proposed to simultaneously strengthen and toughen poly(l-lactide) (PLLA) using a simple rigid-rubber "reinforcing element." This element consists of a rigid graphene oxide (GO) sheet covalently coupled with poly(caprolactone-co-lactide) (PCLLA) rubbery layers, which can be easily synthesized and incorporated into PLLA matrix to develop composites with well-tailored GO/PLLA interfaces...
May 17, 2018: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/29768830/strong-hydrogen-bonding-with-inorganic-pendant-polyhedral-oligomeric-silsesquioxane-nanoparticles-provides-high-glass-transition-temperature-poly-methyl-methacrylate-copolymers
#20
Shu-Ling Yeh, Chao-Yuan Zhu, Shiao-Wei Kuo
We report a series of poly(methyl methacrylate) (PMMA) copolymers containing small amounts of methacrylamide (MAAM) and pendant polyhedral oligomeric silsesquioxane (POSS) methyl acrylate (MAPOSS) segments. The hydrogen bonding interactions of the MAAM monomer units and the inorganic POSS nanoparticle units improved the thermal and mechanical properties of the PMMA copolymers. For example, PMMA copolymerization with 5 wt% PMAAM and 5 wt% PMAPOSS monomers could enhance the glass transition temperature to 142°C, with higher modulus, higher water contact angle, and reasonably high transparency...
January 1, 2018: Journal of Nanoscience and Nanotechnology
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