Monofunctional Aminophenyl Polyhedral Oligomeric Silsesquioxanes - A Model for High Performance Nanocomposite Monomers

2002 ◽  
Author(s):  
Rene I. Gonzalez ◽  
Brent D. Viers ◽  
Timothy Haddad
Keyword(s):  
High Performance ◽  
Polyhedral Oligomeric Silsesquioxanes

scholarly journals Characteristic of Hybrid Cellulose-Amino Functionalized POSS-Silica Nanocomposite and Antimicrobial Activity

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sivalingam Ramesh ◽  
Jaehwan Kim ◽  
Joo-Hyung Kim
Keyword(s):  
Coupling Agent ◽  
High Performance ◽  
Pathogenic Bacteria ◽  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
Morphological Properties ◽  
Regenerated Cellulose ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Covalent Crosslinking ◽  
Silica Hybrid

Recently, cellulose has much attention as an emerging renewable nanomaterial which holds promising properties having unique piezoelectricity, insulating, and biodegradable nature for various applications. Also, the modified properties of cellulose by appropriate chemical modifications in various functional groups with outstanding properties or significantly improved physical, chemical, biological, and electronic properties will widen the way for it to be utilized in different usages. Therefore, in this paper, cellulose-functionalized polyhedral oligomeric silsesquioxanes (POSS) based materials were considered an important class of high-performance hybrid nanocomposite materials. To functionalize the regenerated cellulose, amino functionalized POSS material was synthesized via sol-gel covalent crosslinking process in presence of amino coupling agent. In this reaction, tetraethoxsilane (TEOS) andγ-aminopropyltriethoxy silane (γ-APTES) as coupling agent for metal precursors were selected. The chemical structure of cellulose-amine functionalized bonding and covalent crosslinking hybrids was confirmed by FTIR and1H NMR spectral analysis. From the TEM results, well-dispersed hybrid cellulose-functionalized POSS-silica composites are observed. The resulting cellulose-POSS-silica hybrid nanocomposites materials provided significantly improved the optical transparency, and thermal and morphological properties to compare the cellulose-silica hybrid materials. Further, antimicrobial test against pathogenic bacteria was carried out.

Polyhedral oligomeric silsesquioxanes (POSSs): an important building block for organic optoelectronic materials

2017 ◽  
Vol 5 (22) ◽  
pp. 5283-5298 ◽  
Author(s):  
Zibiao Li ◽  
Junhua Kong ◽  
FuKe Wang ◽  
Chaobin He
Keyword(s):  
High Performance ◽  
Liquid Crystal Display ◽  
Organic Light Emitting Diodes ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Optoelectronic Materials ◽  
Electrochromic Devices ◽  
Light Emitting ◽  
Important Approach ◽  
Organic Optoelectronic ◽  
Important Building Block

Due to the unique hybrid structures and physical properties of polyhedral oligomeric silsesquioxanes (POSSs), hybridation with POSS has been demonstrated to be an important approach to build high-performance organic optoelectronic materials for applications in organic light-emitting diodes (OLEDs), liquid crystal display, sensors and electrochromic devices.

scholarly journals Novel Unsaturated Polyester Nanocomposites via Hybrid 3D POSS-Modified Graphene Oxide Reinforcement: Electro-Technical Application Perspective

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 260 ◽  
Author(s):  
Nidhin Divakaran ◽  
Manoj B. Kale ◽  
T. Senthil ◽  
Suhail Mubarak ◽  
Duraisami Dhamodharan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
High Performance ◽  
Unsaturated Polyester ◽  
Interactive Effect ◽  
Functionalized Graphene ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Functionalized Graphene Oxide ◽  
Limiting Oxygen Index ◽  
Modified Graphene Oxide ◽  
Hybrid Framework

The latest trends in technologies has shifted the focus to developing innovative methods for comprehensive property enhancement of the polymer composites with facile and undemanding experimental techniques. This work reports an elementary technique to fabricate high-performance unsaturated polyester-based nanocomposites. It focuses on the interactive effect of polyhedral oligomeric silsesquioxanes (POSS)-functionalized graphene oxide (GO) within the unsaturated polymermatrix. The hybrid framework of POSS-functionalized graphene oxide has been configured via peptide bonding between the aminopropyl isobutyl POSS and graphene oxide. The synergistic effect of POSS and graphene oxide paved the way for a mechanism to inculcate a hybrid framework within the unsaturated polyester (UP) via in situ polymerization to develop UP/GO-POSS nanocomposites. The surface-appended POSS within the graphene oxide boosted its dispersion in the UP matrix, furnishing an enhancement in tensile strength of the UP/GO-POSS composites by 61.9%, thermal decomposition temperature (10% mass loss) by 69.8 °C and electrical conductivity by 108 S/m, in contrast to pure UP. In particular, the homogenous influence of the POSS-modified GO could be vindicated in the surging of the limiting oxygen index (%) in the as-prepared nanocomposites. The inclusive property amelioration vindicates the use of fabricated nanocomposites as high-performance nanomaterials in electrotechnical applications.

Nano-colloidal silica-tethered polyhedral oligomeric silsesquioxanes with eight branches of 3-aminopropyltriethoxysilane as high-performance catalyst for the preparation of bis-thiazolidinones under ultrasonic conditions

2017 ◽  
Vol 72 (12) ◽  
pp. 927-935 ◽  
Author(s):  
Javad Safaei-Ghomi ◽  
Seyed Hadi Nazemzadeh ◽  
Hossein Shahbazi-Alavi
Keyword(s):  
Alternative Energy ◽  
High Performance ◽  
Colloidal Silica ◽  
Reaction Times ◽  
Mercaptoacetic Acid ◽  
Catalyst Loading ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
One Pot ◽  
H Nmr ◽  
Ultrasonic Conditions

AbstractWe report a class of organic–inorganic hybrid material based on nano-colloidal silica-tethered polyhedral oligomeric silsesquioxanes with eight branches of 3-aminopropyltriethoxysilane [nano-colloidal silica@APTPOSS (a series of polyhedral oligomeric silsesquioxanes with eight branches of 3-aminopropyltriethoxysilane)]. It was characterized by 1H NMR spectroscopy, dynamic light scattering, scanning electron microscope, energy dispersive spectroscopy and thermogravimetric analysis. An easy and rapid method for the synthesis of bis-thiazolidinones has been presented by one-pot pseudo-five-component reaction of benzaldehydes, ethylenediamine and 2-mercaptoacetic acid using nano-colloidal silica@APTPOSS. The reusability of the catalyst and little catalyst loading, excellent yields, short reaction times, using the sonochemical procedure as a green process and an alternative energy source are some benefits of this method.

Preparation and characterization of PLA foam chain extended through grafting octa(epoxycyclohexyl) POSS onto carbon nanotubes

2020 ◽  
Vol 39 (3) ◽  
pp. 117-138
Author(s):  
Wei Liu ◽  
Xunxian Zhu ◽  
Hongxiang Gao ◽  
Xiangdong Su ◽  
Xian Wu
Keyword(s):  
Carbon Nanotubes ◽  
High Performance ◽  
Chain Structure ◽  
Expansion Ratio ◽  
Poly Lactic Acid ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Rigid Foam ◽  
Foaming Behavior ◽  
Melt Elasticity ◽  
Versatile Technique

Improving foamability of poly (lactic acid) (PLA) resin is a key issue for its critical foaming applications with high-performance and ultralow density. However, owing to the rheological nature of linear PLA chain structure with relatively low molecular weight, the overall foamability of PLA resin cannot meet the processing requirements of foaming purpose. Here, we describe a simple and versatile technique to prepare high foamability PLA resin by inducing chain extender through grafting octa(epoxycyclohexyl) polyhedral oligomeric silsesquioxanes (POSS) on carbon nanotubes (CNT). After the orderly assemble of the two nanoparticles, an obvious increase in melt elasticity of PLA is observed. The enhanced melt elasticity of PLA had a significant effect on controlling subsequent foaming behavior. Thus, a homogeneous and finer cellular morphology of PLA rigid foam was obtained with a proper content of CNT-POSS. Eventually, the expansion ratio of chain-extended PLA foam was 13 times higher than that of unmodified PLA foam. The proposed design methodology will potentially pave a way for designing and preparing high-performance PLA rigid foam products.

New Insightl into the Structure-Property Relationships of Hybrid (Inorganic/Organic) Poss™ Thermoplastics

2000 ◽  
Vol 628 ◽  
Author(s):  
Shawn H. Phillips ◽  
Rusty L. Blanski ◽  
Steven A. Svejda ◽  
Timothy S. Haddad ◽  
Andre Lee ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
High Performance ◽  
Molecular Level ◽  
Dielectric Constants ◽  
Organic Polymer ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Structure Property ◽  
Polymer Systems ◽  
Traditional Processing ◽  
Air Force Research Laboratory

The demand for multi-purpose, high-performance polymer systems has resulted in a need for advancing polymer properties beyond what traditional systems can offer. Only through control/alteration at the molecular level can one maximize property enhancements to meet current military and commercial needs. Over the last seven years the Air Force Research Laboratory has developed and incorporated discrete Si-O frameworks (POSS = Polyhedral Oligomeric Silsesquioxanes) into traditional organic polymer systems. This research has resulted in new hybrid inorganic-organic polymer systems with remarkable enhancements in mechanical and physical properties including dramatic increases in both glass transition and decomposition temperatures, reduced flammability, increased moduli and oxidation resistance. We have shown that these enhancements result from the chemical composition (Si-O core) and size (∼15 A in diameter) of the POSS frameworks, and can be copolymerized, grafted, or even blended using traditional processing methods. Recently, we have focused our efforts on understanding and controlling the molecular level interactions between POSS frameworks and the polymer matrix. The development of new POSS monomers has allowed us to study how functionality, size, and geometry enhances the bulk properties of these hybrid materials. For example, increasing the solubility of side groups on the POSS framework results in greater POSS-polymer matrix interactions and increased Tg and storage moduli. Recent studies with POSS blends have resulted in increases in hardness, and reductions in dielectric constants and coefficients of thermal expansion. New results in polymer synthesis, characterization, and applications will be discussed with a strong emphasis on the versatility of this new nanotechnology to many polymer systems.

scholarly journals Effect of POSS-Modified Montmorillonite on Thermal, Mechanical, and Electrical Properties of Unsaturated Polyester Nanocomposites

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2031
Author(s):  
Nidhin Divakaran ◽  
Manoj B. Kale ◽  
Duraisami Dhamodharan ◽  
Suhail Mubarak ◽  
Lixin Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Weight Loss ◽  
Electrical Properties ◽  
High Performance ◽  
In Situ Polymerization ◽  
Unsaturated Polyester ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Sem Images ◽  
Mechanical And Electrical Properties ◽  
Commercial Applications

Montmorillonite (MMT) displays excellent cohesion with an unsaturated polyester (UP) matrix to generate a material which exhibits an extensive range of commercial applications. The organic modification of MMT using polyhedral oligomeric silsesquioxanes (POSS) and the effect of POSS-MMT on the thermal, mechanical, and electrical properties of UP are reported here. Transmission electron microscopy (TEM) images were used to characterize the modification of MMT using POSS. Modified MMT (POSS-MMT) was incorporated, at different wt.% (0.5, 1, 3, 5), into UP via in-situ polymerization. The presence of POSS-MMT enhanced the characteristic properties of UP as a consequence of good dispersion in the polymer matrix. Scanning electron microscopy (SEM) images support effective POSS-MMT dispersion leading to tensile strength enhancement of a UP/POSS-MMT nanocomposite (3 wt.% POSS-MMT) by 54.7% as compared to that for unmodified UP. TGA displays a 35 °C improvement of thermal stability (10% mass loss) at 5% POSS-MMT incorporation, while the electrical conductivity is improved by 108 S/m (3 wt.% POSS-MMT) in comparison to that for unmodified UP. The conventional obstacle of UP associated with shrinkage weight loss during curing seems to be moderated with POSS-MMT incorporation (3%) resulting in a 27.8% reduction in shrinkage weight loss. These fabricated nanocomposites expand the versatility of UP as a high-performance material owing to enhancements of properties.

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

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