keyword
https://read.qxmd.com/read/38203229/green-synthesis-of-soluble-polysilsesquioxane-with-phthalimide-groups
#21
JOURNAL ARTICLE
Artem I Emel'yanov, Yuliya I Bolgova, Olga M Trofimova, Alexander S Pozdnyakov
Soluble polysilsesquioxane containing side-chain phthalimide groups (PSQ-PhI) was synthesized via a solvent- and catalyst-free hydrolytic polycondensation reaction using 2-[3-(triethoxysilyl)propyl]-1 H -isoindole-1,3(2 H )-dione. The composition and structure of polysilsesquioxane was confirmed via 1 H, 13 C, and 29 Si NMR spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, dynamic light scattering, X-ray diffraction analysis, and elemental analysis...
December 19, 2023: International Journal of Molecular Sciences
https://read.qxmd.com/read/38201777/high-thermal-stable-epoxy-resin-through-blending-nanoarchitectonics-with-double-decker-shaped-polyhedral-silsesquioxane-functionalized-benzoxazine-derivatives
#22
JOURNAL ARTICLE
Yang-Chin Kao, Jing-Yu Lin, Wei-Cheng Chen, Mohamed Gamal Mohamed, Chih-Feng Huang, Jung-Hui Chen, Shiao-Wei Kuo
A series of di-functional benzoxazine (BZ) monomers was synthesized, specifically the double-decker silsesquioxane (DDSQ) cage structure (DDSQ-BZ). Comparative analyses were conducted between DDSQ-BZ monomers and the most commonly utilized bisphenol A-functionalized bifunctional benzoxazine (BPA-BZ) monomer. DDSQ-BZ compounds possess better thermal properties such as high char yield and high thermal decomposition temperature ( T d10 ) after thermal ring-opening polymerization (ROP) because the inorganic DDSQ cage nanostructure features a nano-reinforcement effect...
December 29, 2023: Polymers
https://read.qxmd.com/read/38201722/examining-the-water-polymer-interactions-in-non-isocyanate-polyurethane-polyhedral-oligomeric-silsesquioxane-hybrid-hydrogels
#23
JOURNAL ARTICLE
Izabela Łukaszewska, Artur Bukowczan, Konstantinos N Raftopoulos, Krzysztof Pielichowski
Non-isocyanate polyurethane (NIPU) networks physically modified with octa(3-hydroxy-3-methylbutyldimethylsiloxy)POSS (8OHPOSS, 0-10 wt%) were conditioned in environments of different relative humidities (up to 97%) to study water-polymer interactions. The equilibrium sorption isotherms are of Brunauer type III in a water activity range of 0-0.97 and are discussed in terms of the Guggenheim (GAB) sorption model. The study shows that the introduction of 8OHPOSS, even in a large amount (10 wt%), does not hinder the water affinity of the NIPU network despite the hydrophobic nature of POSS; this is attributable to the homogenous dispersion of POSS in the polymer matrix...
December 23, 2023: Polymers
https://read.qxmd.com/read/38153210/cost-effective-ultrabright-silicon-quantum-dots-and-highly-efficient-leds-from-low-carbon-hydrogen-silsesquioxane-polymers
#24
JOURNAL ARTICLE
Honoka Ueda, Ken-Ichi Saitow
Cost-effective methods of synthesizing bright colloidal silicon quantum dots (SiQDs) for use as heavy-metal-free QDs, which have applications as light sources in biomedicine and displays, are required. We report simple protocols for synthesizing ultrabright colloidal SiQDs and fabricating SiQD LEDs based on hydrogen silsesquioxane (HSQ) polymer synthesis. Red photoluminescence with a quantum yield (PLQY) of 60-80% and LEDs with an external quantum efficiency (EQE) of >10% were obtained at 1/3600th of the cost of existing methods...
December 28, 2023: ACS Applied Materials & Interfaces
https://read.qxmd.com/read/38153180/amphiphilic-azo-functionalized-polyoctahedral-oligomeric-silsesquioxane-synthesis-and-photo-switched-efficient-phase-transfer-via-host-guest-encapsulation
#25
JOURNAL ARTICLE
Bagher Eftekhari-Sis, Nasim Amirpour, Aylar Naderahmadian, Maryam Zirak, Mateusz Janeta, Ghodrat Mahmoudi
A new amphiphilic azo-functionalized polyoctahedral oligomeric silsesquioxane (POSS) derivative was synthesized by functionalizing octa(3-aminopropyl)silsesquioxane (OAS-POSS) with 4-((4-(dodecyloxy)phenyl)diazenyl)benzoic acid, affording a hydrophilic amino POSS head and hydrophobic dodecyl tail with a diphenyl-azo connector. Prepared amphiphilic azo-functionalized POSS (azo-POSS) exhibited high ability for encapsulation and transferring cationic dyes into the organic phase by vigorously mixing with aqueous solutions of each dye...
December 28, 2023: ChemPlusChem
https://read.qxmd.com/read/38139977/non-covalent-functionalization-of-graphene-oxide-with-poss-to-improve-the-mechanical-properties-of-epoxy-composites
#26
JOURNAL ARTICLE
Ting Xu, Yumin Jiao, Zhenglian Su, Qin Yin, Lizhou An, Yefa Tan
Phenyl polyhedral oligomeric silsesquioxane (POSS) is modified onto the GO surface by using the strong π-π coupling between a large number of benzene rings at the end of the phenyl POSS structure and the graphite structure in the GO sheet, realizing the non-covalent functionalization of GO (POSS-GO). The POSS-GO-reinforced EP (POSS-GO/EP) composite material is prepared using the casting molding process. The surface morphology of GO before and after modification and its peel dispersion in EP are examined...
December 16, 2023: Polymers
https://read.qxmd.com/read/38139906/effect-of-amino-functionalized-polyhedral-oligomeric-silsesquioxanes-on-structure-property-relationships-of-thermostable-hybrid-cyanate-ester-resin-based-nanocomposites
#27
JOURNAL ARTICLE
Olga Grigoryeva, Alexander Fainleib, Olga Starostenko, Diana Shulzhenko, Agustin Rios de Anda, Fabrice Gouanve, Eliane Espuche, Daniel Grande
Nanocomposites of cyanate ester resin (CER) filled with three different reactive amino-functionalized polyhedral oligomeric silsesquioxane (POSS) were synthesized and characterized. The addition of a small quantity (0.1 wt.%) of amino-POSS chemically grafted to the CER network led to the increasing thermal stability of the CER matrix by 12-15 °C, depending on the type of amino-POSS. A significant increase of the glass transition temperature, T g (DSC data), and the temperature of α relaxation, T α (DMTA data), by 45-55 °C of the CER matrix with loading of nanofillers was evidenced...
December 9, 2023: Polymers
https://read.qxmd.com/read/38133028/processing-and-characterization-of-uv-irradiated-hdpe-poss-fibers
#28
JOURNAL ARTICLE
Ezgi Biçer, Mehmet Kodal, Güralp Özkoç
High-performance polyethylene fibers, renowned for their superior attributes encompassing a high strength, modulus, and lightness, are conventionally manufactured through the gel spinning method. However, this method is encumbered by several drawbacks, including the requisite application of a separate process to eliminate solvents from the fibers and the utilization of chemicals deleterious to both the environment and human health. Alternatively, the adoption of the melt spinning method presents a cleaner and environmentally friendly approach to attain high-performance fibers...
December 13, 2023: Nanomaterials
https://read.qxmd.com/read/38107884/effects-of-hybrid-poss-nanoparticles-on-the-properties-of-thermoplastic-elastomer-toughened-polyamide-6
#29
JOURNAL ARTICLE
Rumeysa Yıldırım, Muhammad Saeed Ullah, Hürol Koçoğlu, Merve Ün, Nazlı Yazıcı Çakır, Gülşah Demir, Duygu Çetin, Gizem Urtekin, Güralp Özkoç, Olcay Mert, Mehmet Kodal
In this study, polyamide 6 (PA6)/thermoplastic elastomer (TPE) blends were prepared to decrease the notch sensitivity of PA6 for automotive applications, and the morphological, rheological, mechanical, and thermal properties of PA6/TPE blends, which are partially miscible or immiscible depending on the TPE ratio, were significantly improved in the existence of polyhedral oligomeric silsesquioxane (POSS) nanoparticles with multiple reactive epoxy groups as compatibilizers. An unstable phase morphology was obtained with the addition of TPE into PA6 without POSS nanoparticles, whereas interfacial interactions between phases in the presence of POSS were enhanced as a result of a significant decrease in the average particle size from 1...
December 12, 2023: ACS Omega
https://read.qxmd.com/read/38107418/intermediate-polymer-relaxation-explains-the-anomalous-rheology-of-nanocomposites-with-ultrasmall-attractive-poss-nanoparticles
#30
JOURNAL ARTICLE
Walter W Young, Reika Katsumata
The rheological properties of entangled polymers loaded with very small, strongly attractive polyhedral oligomeric silsesquioxane (POSS) fillers differ from that of nanocomposites with larger fillers by (1) the shorter breadth of the entanglement plateau and (2) the relatively unchanged terminal viscosity with increasing POSS loading. Although such anomalous rheological properties can rewrite the property-processing map of materials (e.g., high glass transition temperature and low viscosity), their mechanism remains unclear...
December 13, 2023: ACS Polym Au
https://read.qxmd.com/read/38088862/engineering-an-almost-all-waterborne-system-for-transparent-yet-superhydrophobic-surfaces-with-high-liquid-impalement-resistance
#31
JOURNAL ARTICLE
Jingwen Liao, Xilin Lin, Boxu Chen, Mingjin Yang, Wenfeng Liu, Yingfan Cao, Junli Zhou, Jinyi Zhong
Realistically, green manufacturing of transparent superhydrophobic surfaces (SHSs) and high liquid impalement resistance for outdoor engineering are very necessary but pretty challenging. To address this, an almost all-waterborne system composed of synthesized partially open-cage fluorinated polyhedral oligomeric silsesquioxane bearing a pair of -OH (poc-FPOSS-2OH), silica sol, and resin precursor is engineered. The transparent SHSs facilely formed by this system are featured with the exclusive presence of wrapped silica nanoparticle (SiNP) dendritic networks at solid-gas interfaces...
December 13, 2023: Nano Letters
https://read.qxmd.com/read/38081486/g-poss-connected-double-network-starch-gels-for-protein-release
#32
JOURNAL ARTICLE
Seyma Nur Kirmic Cosgun, Deniz Ceylan Tuncaboylu, Mahinur Alemdar
Starch is one of the most frequently preferred natural polymers in hydrogel synthesis. Herein, we combined two strategies of associating brittle and ductile networks in a structure and incorporating inorganic particles into the polymeric gel to design mechanically enhanced nanocomposite double network (DN) starch gels. For the first time in the literature, nanocomposite starch gels (s-NC) were designed by cross-linking starch chains with 8-armed glycidyl-polyhedral oligomeric silsesquioxane (g-POSS) units. Fourier Transform Infrared Spectroscopy and Energy Dispersive X-Ray Spectroscopy analyses have proven that g-POSS is included in the gel structure and is homogeneously distributed throughout the network...
December 9, 2023: International Journal of Biological Macromolecules
https://read.qxmd.com/read/38068220/fabrication-of-liquid-crystalline-polyurethane-polyhedral-oligomeric-silsesquioxane-nanofibers-via-electrospinning
#33
JOURNAL ARTICLE
Artur Bukowczan, Konstantinos N Raftopoulos, Krzysztof Pielichowski
A series of fibrous meshes based on liquid crystalline polyurethane/POSS composites were prepared. Two types of polyhedral oligomeric silsesquioxanes (POSSs) of different structures were chosen to show their influence on electrospun fibers: aromatic-substituted Trisilanolphenyl POSS (TSP-POSS) and isobutyl-substituted Trisilanolisobutyl POSS (TSI-POSS) in amounts of 2 and 6 wt%. The process parameters were selected so that the obtained materials showed the highest possible fiber integrity. Moreover, 20 wt% solutions of LCPU/POSS composites in hexafluoroisopropanol (HFIP) were found to give the best processability...
December 1, 2023: Materials
https://read.qxmd.com/read/38055955/exploring-polyol-functionalized-dendrimers-with-silsesquioxane-cores
#34
JOURNAL ARTICLE
Aleksandra Mrzygłód, Monika Rzonsowska, Beata Dudziec
Silsesquioxane dendrimers offer versatile structural potential, prompting our innovative synthesis of G1 and G2 polyol dendritic systems with diverse silsesquioxane cores, ranging from mono-T8 to difunctional and tetrafunctional double-decker silsesquioxanes. Through a strategic combination of hydrosilylation and O -silylation reactions, we have formed an extensive compound library. A major focus was directed toward investigating the reaction conditions of G1.5 dendrimers, as well as evaluating the stability and reactivity of the novel -O-Me2 Si-H group...
December 6, 2023: Inorganic Chemistry
https://read.qxmd.com/read/38055200/polyhedral-oligomeric-silsesquioxane-d3h-rsio1-5-14
#35
JOURNAL ARTICLE
Marc Hunsicker, Ankur Ankur, Bernd Morgenstern, Michael Zimmer, David Scheschkewitz
While smaller polyhedral oligomeric silsesquioxanes TnRn (POSS) are readily accessible or even commercially available, unambiguously authenticated larger systems (n > 12) have barely been reported. Synthesis and isolation procedures are lengthy, and yields are often very low. Herein, we present the surprisingly straightforward and high-yielding access to the phenyl-substituted derivative of a so far only postulated second D3h-symmetric T14 isomer and with that the largest crystallographically characterized POSS cage with organic substituents...
December 6, 2023: Chemistry: a European Journal
https://read.qxmd.com/read/38015470/a-trinuclear-metallasilsesquioxane-of-uranium-iii
#36
JOURNAL ARTICLE
Maxime Tricoire, Nadir Jori, Farzaneh Fadaei Tirani, Rosario Scopelliti, Ivica Z Ivković, Louise S Natrajan, Marinella Mazzanti
The silsesquioxane ligand ( i Bu)7 Si7 O9 (OH)3 ( iBu POSSH3 ) is revealed as an attractive system for the assembly of robust polynuclear complexes of uranium(III) and allowed the isolation of the first example of a trinuclear U(III) complex ([U3 ( iBu POSS)3 ]) that exhibits magnetic communication and promotes dinitrogen reduction in the presence of reducing agent.
November 28, 2023: Chemical Communications: Chem Comm
https://read.qxmd.com/read/38003729/effects-of-segment-length-and-crosslinking-via-poss-on-the-calorimetric-and-dynamic-glass-transition-of-polyurethanes-with-aliphatic-hard-segments
#37
JOURNAL ARTICLE
Konstantinos N Raftopoulos, Panagiotis A Klonos, Patrycja Tworzydło, Jan Ozimek, Edyta Hebda, Apostolos Kyritsis, Krzysztof Pielichowski
The glass transition in polyurethanes is a complicated phenomenon governed by a multitude of factors, including the microphase separation, which in turn depends strongly on the molar mass of the hard and soft segments, as well as the presence of additives. In this work, we study the effects of the segments' length on the microphase separation and consequently on the calorimetric and dynamic glass transition of a polyurethane with aliphatic, "flexible" hard segments. It is found that the dependence of the calorimetric glass transition follows the same principles as those in systems with aromatic hard segments...
November 20, 2023: International Journal of Molecular Sciences
https://read.qxmd.com/read/38000199/organic-silica-hybrid-monolithic-sorbents-for-sample-preparation-techniques-a-review-on-advances-in-synthesis-characterization-and-applications
#38
JOURNAL ARTICLE
Israel D Souza, Maria Eugênia C Queiroz
Organic-silica hybrid monolithic materials have attracted considerable attention as potential stationary phases in separation science. These materials combine the advantages of organic polymer and silica-based monoliths, including easy preparation, lower back pressure, high permeability, excellent mechanical strength, thermal stability, and tunable surface chemistry with high surface area and selectivity. The outstanding chromatographic efficiency as stationary phase of hybrid monolithic capillary columns for capillary liquid chromatography and capillary electrochromatography has been reported in many papers...
November 19, 2023: Journal of Chromatography. A
https://read.qxmd.com/read/37990586/synthesis-and-mesomorphic-properties-of-side-on-hybrid-liquid-crystalline-silsesquioxanes
#39
JOURNAL ARTICLE
Kosuke Kaneko, Atsuhiko Mandai, Benoît Heinrich, Bertrand Donnio, Tomonori Hanasaki
Novel hybrid silsesquioxane-based liquid crystalline derivatives with varied lengths of spacers and tails have been synthesized by hydrosilylation reactions of octakis(dimethylsiloxy)silsesquioxane and side-on mesogens via a platinum catalyst. The thermal behavior of three types of silsesquioxane-based liquid crystals (LCs), differentiated by the molecular structure of mesogens, was investigated by differential scanning calorimetry (DSC) and polarising optical microscopy (POM). Temperature-dependent small and wide-angle X-ray scattering was used to verify liquid crystalline phases, revealing that the silsesquioxane-based derivatives formed hexagonal columnar and nematic mesophases, and the effect of the molecular structure of the mesogens and the spacer length on the formation of LC phases is discussed...
November 22, 2023: Soft Matter
https://read.qxmd.com/read/37939756/preparation-and-characterization-of-hemicellulose-films-reinforced-with-amino-polyhedral-oligomeric-silsesquioxane-for-biodegradable-packaging
#40
JOURNAL ARTICLE
Jing Li, Wei Wang, Han Wu, Feng Peng, Hui Gao, Ying Guan
Biomass is one of the powerful alternatives to petroleum-based packaging materials. Herein, carboxymethyl hemicellulose (CMH) based films (CPF) were prepared using a convenient strategy. The chains of CMH provided the necessary supporting matrix, and the aminopropyl polyhedral oligomeric silsesquioxane (POSS-NH2 ) regulated the thermal and barrier properties of the CPF. The secondary amide groups and hydrogen bond were appeared in chemical structure, and SEM-EDS results indicated the preferable dispersion and compatibility of POSS-NH2 in CPFs...
November 6, 2023: International Journal of Biological Macromolecules
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