scholarly journals Structure/Property Relationships of Poly(L-lactic Acid)/Mesoporous Silica Nanocomposites

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Javier Gudiño-Rivera ◽  
Francisco J. Medellín-Rodríguez ◽  
Carlos Ávila-Orta ◽  
Alma G. Palestino-Escobedo ◽  
Saúl Sánchez-Valdés
Keyword(s):  
Lactic Acid ◽  
Mesoporous Silica ◽  
Surface Characterization ◽  
Crystal Habit ◽  
Structure Property ◽  
Silica Nanocomposites ◽  
Structure Property Relationships ◽  
Silica Concentration ◽  
Biodegradable Poly

Biodegradable poly(L-lactic acid) (PLLA)/mesoporous silica nanocomposites were prepared by grafting L-lactic acid oligomer onto silanol groups at the surface of mesoporous silica (SBA-15). The infrared results showed that the lactic acid oligomer was grafted onto the mesoporous silica. Surface characterization of mesoporous silica proved that the grafted oligomer blocked the entry of nitrogen into the mesopores. Thermal analysis measurements showed evidence that, once mixed with PLLA, SBA-15 not only nucleated the PLLA but also increased the total amount of crystallinity. Neat PLLA and its nanocomposites crystallized in the same crystal habit and, as expected, PLLA had a defined periodicity compared with the nanocomposites. This was because the grafted macromolecules on silica tended to cover the lamellar crystalline order. The g-SBA-15 nanoparticles improved the tensile moduli, increasing also the tensile strength of the resultant nanocomposites. Overall, the silica concentration tended to form a brittle material.

scholarly journals Correction: Synthesis and characterization of novel Li-stuffed garnet-like Li5+2xLa3Ta2−xGdxO12 (0 ≤ x ≤ 0.55): structure–property relationships

2017 ◽  
Vol 46 (25) ◽  
pp. 8304-8305
Author(s):  
Dalia M. Abdel Basset ◽  
Suresh Mulmi ◽  
Mohammed S. El-Bana ◽  
Suzan S. Fouad ◽  
Venkataraman Thangadurai
Keyword(s):  
Synthesis And Characterization ◽  
Structure Property ◽  
Dalton Trans ◽  
Structure Property Relationships

Correction for ‘Synthesis and characterization of novel Li-stuffed garnet-like Li5+2xLa3Ta2−xGdxO12 (0 ≤ x ≤ 0.55): structure–property relationships’ by Dalia M. Abdel Basset, et al., Dalton Trans., 2017, 46, 933–946.

Preparation and Characterization of Several Conducting Transition Metal Oxides

1989 ◽  
Vol 156 ◽  
Author(s):  
Aaron Wold ◽  
Kirby Dwight
Keyword(s):  
Transition Metal ◽  
Single Crystal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Structure Property ◽  
Metallic Behavior ◽  
Structure Property Relationships ◽  
Conduction Bands ◽  
Metal Metal

ABSTRACTThe structure-property relationships of several conducting transition metal oxides, as well as their preparative methods, are presented in this paper. The importance of preparing homogeneous phases with precisely known stoichiometry is emphasized. A comparison is also made of the various techniques used to prepare both polycrystalline and single crystal samples. For transition metal oxides, the metallic properties are discussed either in terms of metal-metal distances which are short enough to result in metallic behavior, or in terms of the formation of a П* conduction band resulting from covalent metal-oxygen interactions. Metallic behavior is observed when the conduction bands are populated with either electrons or holes. The concentration of these carriers can be affected by either cation or anion substitutions. The discussion in this presentation will be limited to the elements Re, Ti, V, Cr, Mo, and Cu.

Imidazole-Based Solvents and Membranes for CO2 Capture Applications

2014 ◽  
Vol 1673 ◽  
Author(s):  
Jason E. Bara ◽  
Matthew S. Shannon ◽  
W. Jeffrey Horne ◽  
John W. Whitley ◽  
Haining Liu ◽  
...  
Keyword(s):  
Flue Gas ◽  
Process Design ◽  
Predictive Models ◽  
Power Plants ◽  
Absorption Capacity ◽  
Computational Studies ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Imidazole Compounds

ABSTRACTImidazoles present a tunable, versatile and economical platform for the development of novel liquid solvents and polymer membranes for CO2 capture. An overview of our studies in this area is presented, with emphasis on characterization of structure-property relationships in imidazole-based materials through both experimental and computational studies. To this end, a growing library of systematically varied imidazole compounds has been synthesized using only commercial available starting materials and straightforward reactions. Using this library of compounds, we have sought to understand and develop predictive models for thermophysical properties relating to process design, including: density, viscosity, vapor pressure, pKa and CO2 absorption capacity. Furthermore, we have discovered that imidazoles are stable in the presence of SO2 and can form reversible 1:1 adducts, which can be beneficial as SO2 is typically present at ppm levels alongside CO2 in flue gas from coal-fired power plants.

Mechanical and Viscoelastic Characterization of Hyperbranched Polyisobutylenes

2002 ◽  
Vol 75 (5) ◽  
pp. 853-864 ◽  
Author(s):  
Judit E. Puskas ◽  
Christophe Paulo ◽  
Volker Altstädt
Keyword(s):  
Molecular Weight ◽  
Butyl Rubber ◽  
Structure Property ◽  
Carbocationic Polymerization ◽  
Molecular Weights ◽  
Structure Property Relationships ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Living Carbocationic Polymerization

Abstract Structure-property relationships were investigated in hyperbranched polyisobutylenes, in comparison with commercial linear butyl rubber. The gel-free, soluble hyperbranched polyisobutylenes, synthesized by living carbocationic polymerization, had molecular weights, Mw≈400,000 to 1,000,000 g/mol, molecular weight distributions, MWD ≈1.2 to 2.6, and branching frequencies, BR ≈ 4 to 60. The mechanical and viscoelastic characterization of these polymers revealed interesting properties, including the characteristics of crosslinked rubbers.

Characterization of Aerogels – Challenges and Prospects

2014 ◽  
Vol 91 ◽  
pp. 54-63 ◽  
Author(s):  
Gudrun Reichenauer
Keyword(s):  
Catalyst Support ◽  
Optical Devices ◽  
Structure Property ◽  
Severe Problem ◽  
The Past ◽  
Structure Property Relationships ◽  
Potential Applications ◽  
Directed Development ◽  
Non Destructive

Aerogels are porous materials with potential applications in fields ranging from thermal insulation, catalyst support, filters, electrical storage, components in optical devices, mechanical damping all the way to drug release. However, careful reliable characterization is the base for both, understanding of fundamental structure - property relationships as well as a directed development of materials and composites for specific applications. The review therefore addressed severe problem upon aerogel characterization that have been identified in the past and presents reliable non-destructive alternatives and novel methods that can be applied for the characterization of aerogels as well as their gel precursors.

Surface characterization of poly(lactic acid)/everolimus and poly(ethylene vinyl alcohol)/everolimus stents

Drug Delivery ◽  
2010 ◽  
Vol 17 (6) ◽  
pp. 376-384 ◽  
Author(s):  
Ming Wu ◽  
Lothar Kleiner ◽  
Fuh-Wei Tang ◽  
Syed Hossainy ◽  
Martyn C. Davies ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Vinyl Alcohol ◽  
Surface Characterization ◽  
Poly Lactic Acid ◽  
Ethylene Vinyl Alcohol ◽  
Poly Ethylene

Micromechanical characterization of soft, biopolymeric hydrogels: stiffness, resilience, and failure

Soft Matter ◽  
2018 ◽  
Vol 14 (18) ◽  
pp. 3478-3489 ◽  
Author(s):  
Shruti Rattan ◽  
Linqing Li ◽  
Hang Kuen Lau ◽  
Alfred J. Crosby ◽  
Kristi L. Kiick
Keyword(s):  
Tissue Engineering ◽  
Local Structure ◽  
Structure Property ◽  
Detailed Understanding ◽  
Structure Property Relationships ◽  
Micromechanical Characterization

Detailed understanding of the local structure–property relationships in soft biopolymeric hydrogels can be instrumental for applications in regenerative tissue engineering.

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