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https://www.readbyqxmd.com/read/30501178/unraveling-the-self-assembly-of-hetero-cluster-janus-dumbbells-into-hybrid-cubosomes-with-internal-double-diamond-structure
#1
Hong-Kai Liu, Li-Jun Ren, Han Wu, Yong-Li Ma, Sven Richter, Michael Godehardt, Christian Kübel, Wei Wang
Cubosomes are bicontinuous cubic-phase particles generated by amphiphile self-assembly with bicontinuous cubic phases, which creates an intricate network of interconnected nanochannels endows these materials with special functions for advanced applications. On the other hand, clusters are an attractive class of molecules that exhibit intriguing functions and properties that differ from those of atoms and nanoparticles. Inspired by lipid self-assembly and attracted to the new functionalities of clusters, we prepared special hetero-cluster Janus dumbbells (HCJDs) composed of dissimilar nanoclusters namely, a polyoxometalate and polyhedral oligomeric silsesquioxane...
December 2, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/30500698/functional-polyhedral-oligomeric-silsesquioxane-reinforced-poly-lactic-acid-nanocomposites-for-biomedical-applications
#2
Lin Huang, Jianwang Tan, Wenqiang Li, Lin Zhou, Zhibin Liu, Binghong Luo, Lu Lu, Changren Zhou
Polyhedral oligomeric silsesquioxane reinforced poly (L-lactic acid) nanocomposites (PLLA/POSS) were prepared to overcome the insufficient mechanical properties of PLLA. In order to improve the compatibility between the nanofillers and matrix, PLLA chains were grafted onto the POSS nanoparticles via microwave-assisted ring opening polymerization (ROP). Herein, a series of interface-modified polyhedral oligomeric silsesquioxane (POSS-(PLLA)32 ) nanoparticles with various PLLA tail lengths were synthesized and the influence of the structure and additional amount of POSS nanoparticles on the properties of PLLA based nanocomposites were studied...
November 19, 2018: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/30472566/characterization-of-low-shrinkage-dental-composites-containing-methacrylethyl-polyhedral-oligomeric-silsesquioxane-me-poss
#3
Talita Angelina Tavares Canellas, Aline de Almeida Neves, Ingrid Kimberly Bezerra Dos Santos, Amanda Ramos Pereira de Rezende, Carlos Eduardo Fellows, Eduardo Moreira da Silva
The aim of this study was to characterize low-shrinkage dental composites containing methacrylethyl-polyhedral oligomeric silsesquioxane (ME-POSS). Four experimental composites were manufactured, two of which contained organic matrixes of BisGMA-TEGDMA (70/30 wt% - BGC) and BisEMA-TEGDMA (80/20 wt% - BEC). The two other experimental composites replaced BisGMA and BisEMA with 25 wt% of ME-POSS (BGP and BEP). The composites also contained 70 wt% of 0.7 µm silanized BaBSi particles. The following properties were evaluated: Degree of conversion (DC%), volumetric polymerization shrinkage (VS%), polymerization shrinkage stress (Pss), flexural strength (FS), Flexural modulus (FM), hardness (KHN), water sorption (Wsp ), water solubility (Wsl ), diffusion coefficient (D), and wear...
October 18, 2018: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/30469206/thermal-and-optical-performance-of-glass-cloth-reinforced-organic-inorganic-hybrid-polymer-composite-film
#4
Jeong-Eun Jeon, Hye-Hyun Kim, Nam-Ju Jo
Recently there has been considerable interest in flexible display as the next-generation display. The flexible plastic has been recommended as a strong candidate for substrate, but these plastic substrates have many problems to provide the comparable properties of dimensional stability, thermal stability, and solvent resistance to glass in order to apply conventional thin film transistor technology to flexible display. Then in this study, a glass cloth reinforced polymer (GCRP) composite was prepared. To improve the thermal property, glass cloth with an excellent coefficient of thermal expansion (CTE) for reinforcement and organic-inorganic hybrid nanomaterial with polyhedral oligomeric silsesquioxane (POSS) material having excellent heat resistance were introduced to ensure the excellent properties like transmittance, haze, yellow index, thermal stability and chemical resistance...
March 1, 2019: Journal of Nanoscience and Nanotechnology
https://www.readbyqxmd.com/read/30444347/flow-assisted-switchable-catalysis-of-metal-ions-in-a-microenvelope-system-embedded-with-core-shell-polymers
#5
Niraj K Vishwakarma, Yoon-Ho Hwang, Praveen Reddy Adiyala, Dong-Pyo Kim
Many efforts have been made on stimuli-responsive switchable catalysis to trigger catalytic activity over various chemical reactions. However, the reported light-, pH- or chemically responsive organocatalysts are mostly incomplete in the aspects of shielding efficiency and long-term performance. Here, we advance the flow-assisted switchable catalysis of metal ions in a microenvelope system that allows  the on-off catalysis mode on demand for long-lasting catalytic activity. Various metal-ion catalysts can be selectively embedded in a novel polymeric core-shell of the heteroarm star copolymer of poly(styrene) and poly(4-vinylpyridine) emanated from a polyhedral oligomeric silsesquioxane center...
November 29, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/30429984/anion-identification-using-silsesquioxane-cages
#6
Supphachok Chanmungkalakul, Vuthichai Ervithayasuporn, Patcharaporn Boonkitti, Alisa Phuekphong, Nicha Prigyai, Sumana Kladsomboon, Suda Kiatkamjornwong
Anthracene-conjugated octameric silsesquioxane (AnSQ) cages, prepared via Heck coupling between octavinylsilsesquioxane (OVS) and 9-bromoanthracene, thermodynamically display intramolecular excimer emissions. More importantly, these hosts are sensitive to each anionic guest, thereby resulting in change of anthracene excimer formation, displaying the solvent-dependent fluorescence and allowing us to distinguish up to four ions such as F- , OH- , CN- and PO4 3- by fluorescence spectroscopy. Depending on the solvent polarity, for example, both F- and CN- quenched the fluorescence emission intensity in THF, but only F- could enhance the fluorescence in all other solvents...
October 28, 2018: Chemical Science
https://www.readbyqxmd.com/read/30424607/hydrophobic-nature-of-methacrylate-poss-in-combination-with-2-methacryloyloxy-ethyl-phosphorylcholine-for-enhanced-solubility-and-controlled-release-of-paclitaxel
#7
Suchismita Chatterjee, Tooru Ooya
Amphiphilic copolymers consisting of 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) and hydrophobic monomers are known as biomaterials for the administration of poorly water-soluble drugs such as paclitaxel (PTX). However, the hydrophobic monomers to be copolymerized with MPC have not been optimized for PTX solubilization and its dosage forms. Here, we show the enhanced PTX solubility by only an MPC-based amphiphilic copolymer using a polyhedral oligomeric silsesquioxane (POSS) methacrylate (MA) bearing an ethyl (C2 H5 ) group as a vertex group...
November 21, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/30424191/self-assembly-behavior-and-ph-stimuli-responsive-property-of-poss-based-amphiphilic-block-copolymers-in-solution
#8
Yiting Xu, Kaiwei He, Hongchao Wang, Meng Li, Tong Shen, Xinyu Liu, Conghui Yuan, Lizong Dai
Stimuli-responsive polymeric systems containing special responsive moieties can undergo alteration of chemical structures and physical properties in response to external stimulus. We synthesized a hybrid amphiphilic block copolymer containing methoxy polyethylene glycol (MePEG), methacrylate isobutyl polyhedral oligomeric silsesquioxane (MAPOSS) and 2-(diisopropylamino)ethyl methacrylate (DPA) named MePEG- b -P(MAPOSS- co -DPA) via atom transfer radical polymerization (ATRP). Spherical micelles with a core-shell structure were obtained by a self-assembly process based on MePEG- b -P(MAPOSS- co -DPA), which showed a pH-responsive property...
May 24, 2018: Micromachines
https://www.readbyqxmd.com/read/30402874/charged-molecular-silica-trigger-in-vitro-netosis-in-human-granulocytes-via-both-oxidative-and-autophagic-pathways
#9
M Rizzi, F Carniato, S Tonello, M Migliario, M Invernizzi, V Rocchetti, L Marchese, F Renò
OBJECTIVE: Neutrophils play a key role in immunity and are known to respond to exogenous threats by releasing neutrophil extracellular traps (NETs) through NETosis, a process involving the release of neutrophils nuclear DNA decorated with proteins into the extracellular space. In this study, attention has been focused on the ability of differently charged molecular systems polyhedral oligomeric silsesquioxanes (POSS) to induce NETosis. MATERIALS AND METHODS: NETs formation was induced by phorbol myristate acetate (PMA) (positive control) and POSS treatment and visualized by confocal microscopy...
October 2018: European Review for Medical and Pharmacological Sciences
https://www.readbyqxmd.com/read/30368062/improvement-of-anticorrosion-ability-of-epoxy-matrix-in-simulate-marine-environment-by-filled-with-superhydrophobic-poss-go-nanosheets
#10
Yuwei Ye, Dawei Zhang, Tong Liu, Zhiyong Liu, Wei Liu, Jibin Pu, Hao Chen, Haichao Zhao, Xiaogang Li
Super-hydrophobicity polyhedral oligomeric silsesquioxane-modified graphene oxide (POSS-GO) was synthesized by one-step reaction between graphene oxide (GO) and aminopropylisobutyl polyhedral oligomeric silsesquioxane (POSS-NH2 ). Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra indicated that the POSS were successfully connected to the edge and surface of GO nanosheets. Scanning probe microscope (SPM) and transmission electron microscope (TEM) images demonstrated that the POSS-GO with a thickness of 1...
October 16, 2018: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/30351062/cesium-carbonate-catalyzed-oxidation-of-substituted-phenylsilanes-for-the-efficient-synthesis-of-polyhedral-oligomeric-silsesquioxanes
#11
Yuefeng Li, Chunming Cui
Cesium carbonate-catalyzed oxidation of substituted phenylsilanes (ArSiH3 ) in N, N-dimethylformamide (DMF) at room temperature for the efficient synthesis of polyhedral oligomeric silsesquioxanes (POSS) was described. This protocol allowed the rapid and selective access to several types of new POSS cages in modest to good yields under nonaqueous conditions. Depending on the bulkiness of the substituents on the phenyl rings, hexa- (T6 ), octa- (T8 ), and dodecaphenylsilsesquioxanes (T12 ) can be selectively obtained...
November 5, 2018: Inorganic Chemistry
https://www.readbyqxmd.com/read/30349979/polyurethane-synthesis-for-vascular-application
#12
Zahra Zaredar, Fahimeh Askari, Parvin Shokrolahi
Three polyurethane formulations were prepared on the basis of siloxane; two formulations contained 1% and 3% of a hydroxyl functionalized polyhedral oligomeric silsesquioxane [POSS (ROH)2 ] nano-particles (as a co-chain extender) and one was without nano-particle. Structures of the polyurethanes were characterized by FTIR and SEM. The effect of POSS nano-particles on properties of the synthesized PUs was examined for vascular applications by tensile test, contact angle, SEM, AFM and endothelial cells viability evaluation...
October 22, 2018: Progress in Biomaterials
https://www.readbyqxmd.com/read/30318668/enhancing-the-efficacy-of-photodynamic-therapy-pdt-through-a-porphyrin-poss-alternating-copolymer
#13
Weian Zhang, Jianqiu Jin, Yucheng Zhu, Zhenghe Zhang
Aggregation-induced quenching (AIQ) of photosensitizers greatly reduces the quantum yield of singlet oxygen generation and mitigates the efficacy of photodynamic therapy (PDT). We have prepared an alternating copolymer starting from 4-vinylbenzyl-terminated tetraphenylporphyrin (VBTPP) and maleimide isobutyl polyhedral oligomeric silsesquioxane (MIPOSS), via alternating reversible addition-fragmentation chain transfer (RAFT) polymerization. Porphyrin and POSS are installed on the amphiphilic block copolymers backbone in an alternating fashion and POSS completely inhibits the aggregation of porphyrin units via stacking...
October 14, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/30310890/a-polyhedral-oligomeric-silsesquioxane-molecular-sieve-codoped-molecularly-imprinted-polymer-for-gastroretentive-drug-controlled-release-in-vivo
#14
Xu Wang, Fang-Fang Yang, Li-Ping Zhang, Yan-Ping Huang, Zhao-Sheng Liu
Flotation drug delivery system (FDDS) is recognized as an efficient means to improve the therapeutic efficiency and enhance the drug bioavailability. Herein, we have developed a molecularly imprinted polymer (MIP) against capecitabine (CAP) to fabricate a FDDS by exploiting polyhedral oligomeric silsesquioxane (POSS) and Mobil composition of matter no. 41 (MCM-41) as the codopant. The synergistic effect of POSS and MCM-41 endows MIPs with enhanced imprinting effect and improved mass transfer efficiency. The impacts of the type of dopant, the type of functional monomer, the template/functional monomer ratio and the functional monomer/cross-linker ratio on imprinting effect have been investigated in detail...
November 20, 2018: Biomaterials Science
https://www.readbyqxmd.com/read/30277619/multivalent-fucosides-with-nanomolar-affinity-for-the-aspergillus-fumigatus-lectin-flea-prevent-spore-adhesion-to-pneumocytes
#15
Victor Lehot, Yoan Brissonnet, Christophe Dussouy, Sami Brument, Aurore Cabanettes, Emilie Gillon, David Deniaud, Annabelle Varrot, Patrice Le Pape, Sébastien G Gouin
FleA (or AFL), a fucose lectin, was recently identified in the opportunistic mold Aspergillus fumigatus, which causes fatal lung infections in immunocompromised patients. We designed di-, hexa- and octavalent fucosides with various spacer arm lengths to block the hexameric FleA through chelation. Microcalorimetry measurements showed that the ethylene glycol (EG) spacer arm length has a strong influence on the binding affinity of the divalent fucosides. The relationship between the EG length and chelate binding efficiency to FleA was explored according to polymer theory...
October 2, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/30272655/single-digit-nanometer-electron-beam-lithography-with-an-aberration-corrected-scanning-transmission-electron-microscope
#16
Fernando E Camino, Vitor R Manfrinato, Aaron Stein, Lihua Zhang, Ming Lu, Eric A Stach, Charles T Black
We demonstrate extension of electron-beam lithography using conventional resists and pattern transfer processes to single-digit nanometer dimensions by employing an aberration-corrected scanning transmission electron microscope as the exposure tool. Here, we present results of single-digit nanometer patterning of two widely used electron-beam resists: poly (methyl methacrylate) and hydrogen silsesquioxane. The method achieves sub-5 nanometer features in poly (methyl methacrylate) and sub-10 nanometer resolution in hydrogen silsesquioxane...
September 14, 2018: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/30262758/self-assembly-and-applications-of-amphiphilic-hybrid-poss-copolymers
#17
REVIEW
Hong Chi, Mingyue Wang, Yiting Xiao, Fuke Wang, Joshy K S
Understanding the mechanism of molecular self-assembly to form well-organized nanostructures is essential in the field of supramolecular chemistry. Particularly, amphiphilic copolymers incorporated with polyhedral oligomeric silsesquioxanes (POSSs) have been one of the most promising materials in material science, engineering, and biomedical fields. In this review, new ideas and research works which have been carried out over the last several years in this relatively new area with a main focus on their mechanism in self-assembly and applications are discussed...
September 27, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/30245809/on-chip-excitation-of-single-germanium-vacancies-in-nanodiamonds-embedded-in-plasmonic-waveguides
#18
Hamidreza Siampour, Shailesh Kumar, Valery A Davydov, Liudmila F Kulikova, Viatcheslav N Agafonov, Sergey I Bozhevolnyi
Monolithic integration of quantum emitters in nanoscale plasmonic circuitry requires low-loss plasmonic configurations capable of confining light well below the diffraction limit. We demonstrated on-chip remote excitation of nanodiamond-embedded single quantum emitters by plasmonic modes of dielectric ridges atop colloidal silver crystals. The nanodiamonds were produced to incorporate single germanium-vacancy (GeV) centres, providing bright, spectrally narrow and stable single-photon sources suitable for highly integrated circuits...
2018: Light, Science & Applications
https://www.readbyqxmd.com/read/30230070/a-diarylethene-based-super-photoswitch-and-its-photomodulation-performance-on-fluorescence-of-conjugated-polymer
#19
Ronghua Liu, Yu Yang, Qianling Cui, Wenqiang Xu, Rui Peng, Lidong Li
Photochromic diarylethene derivatives, which can reversibly switch the fluorescence of adjacent fluorophores between the ON and OFF states under light irradiation, have been widely used to construct photoswitchable materials. Herein, we integrate eight dithienylethene (DTE) groups onto one polyhedral oligomeric silsesquioxanes (POSS) core, obtaining a novel super molecular photoswitch. After being doped into conjugated polymer nanoparticles, the POSS-DTE8 molecules shows a higher contrast on/off photoswitching performance and a quicker responsive speed than free DTE molecules at same molar concentration of photochromic units...
September 19, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/30223245/poly-silsesquioxanes-and-poly-siloxanes-grafted-with-n-acetylcysteine-for-eradicating-mature-bacterial-biofilms-in-water-environment
#20
Maria Nowacka, Anna Rygała, Dorota Kręgiel, Anna Kowalewska
Bacteria adapt to their living environment forming organised biofilms. The survival strategy makes them more resistant to disinfectants, which results in acute biofilm-caused infections, secondary water pollution by biofilm metabolites and bio-corrosion. New, efficient and environmentally friendly strategies must be developed to solve this problem. Water soluble N-acetyl derivative of L-cysteine (NAC) is a non-toxic compound of mucolytic and bacteriostatic properties that can interfere with the formation of biofilms...
September 10, 2018: Colloids and Surfaces. B, Biointerfaces
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