scholarly journals Self-Assembling Siloxane Nanoparticles with Three Phases

10.5772/35405 ◽  
2012 ◽  
Author(s):  
Masatoshi Iji
Keyword(s):  
2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Masatoshi Iji ◽  
Naoki Morishita

Biopolymer nanocomposites (bio-nanocomposite) consisting of poly-L-lactic acid (PLLA) and siloxane nanoparticles with three phases, a high-density siloxane phase (plural cores), an elastomeric silicone phase, and a caprolactone oligomer phase, were developed to increase the mechanical properties of PLLA. The nanoparticles, average size of 13 nm, were self-assembled by aggregation and condensation of an organosiloxane with three units: isocyanatepropyltrimethoxysilane (IPTS), polymethylpropyloxysiloxane (PMPS), and a caprolactone oligomer (CLO), which form each phase. The bio-nanocomposite was produced using PLLA and the nanoparticles. Bending and tensile testing showed that the use of these nanoparticles (5 wt% in PLLA) greatly increases the tenacity (breaking strain) of PLLA while maintaining its relatively high breaking (maximum) strength. The elongation of the nanocomposite was more than twice that of PLLA while the elasticity modulus and breaking (maximum) strength were comparable to those of PLLA. The nanoparticles also increased the impact strength of PLLA. The use of the nanoparticles almost did not show adverse affect on the thermal resistance of PLLA. The nanocomposite’s heat resistance indicated by the glass transition temperature and heat distortion temperature was fairly kept. The decomposition temperature of the nanocomposite somewhat increased.


2010 ◽  
Vol 43 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Masatoshi Iji ◽  
Naoki Morishita ◽  
Hiroyuki Kai

Author(s):  
George C. Ruben ◽  
Kenneth A. Marx

Certain double stranded DNA bacteriophage and viruses are thought to have their DNA organized into large torus shaped structures. Morphologically, these poorly understood biological DNA tertiary structures resemble spermidine-condensed DNA complexes formed in vitro in the total absence of other macromolecules normally synthesized by the pathogens for the purpose of their own DNA packaging. Therefore, we have studied the tertiary structure of these self-assembling torus shaped spermidine- DNA complexes in a series of reports. Using freeze-etch, low Pt-C metal (10-15Å) replicas, we have visualized the microscopic DNA organization of both calf Thymus( CT) and linear 0X-174 RFII DNA toruses. In these structures DNA is circumferentially wound, continuously, around the torus into a semi-crystalline, hexagonal packed array of parallel DNA helix sections.


2020 ◽  
Author(s):  
Will R Henderson ◽  
Danielle E. Fagnani ◽  
Yu Zhu ◽  
Guancen Liu ◽  
Ronald K. Castellano

Nature ◽  
1999 ◽  
Author(s):  
Philip Ball
Keyword(s):  

1988 ◽  
Vol 15 (1) ◽  
pp. 23-51 ◽  
Author(s):  
R McCullagh ◽  
M Andrews ◽  
Anne Clarke ◽  
G Collins ◽  
E Halpin ◽  
...  

Summary Excavations at Newton have revealed three phases of land use. Mesolithic activity was restricted to small flint working and domestic sites. A Neolithic phase appears to relate to a fragile soil resource which rapidly declined in quality. The final phase, possibly related to a Christian Irish presence on the island, occurs late in the sequence.


2015 ◽  
Vol 32 (1) ◽  
pp. 40-77
Author(s):  
Peter Mercer-Taylor

The notion that there might be autobiographical, or personally confessional, registers at work in Mendelssohn’s 1846 Elijah has long been established, with three interpretive approaches prevailing: the first, famously advanced by Prince Albert, compares Mendelssohn’s own artistic achievements with Elijah’s prophetic ones; the second, in Eric Werner’s dramatic formulation, discerns in the aria “It is enough” a confession of Mendelssohn’s own “weakening will to live”; the third portrays Elijah as a testimonial on Mendelssohn’s relationship to the Judaism of his birth and/or to the Christianity of his youth and adulthood. This article explores a fourth, essentially untested, interpretive approach: the possibility that Mendelssohn crafts from Elijah’s story a heartfelt affirmation of domesticity, an expression of his growing fascination with retiring to a quiet existence in the bosom of his family. The argument unfolds in three phases. In the first, the focus is on that climactic passage in Elijah’s Second Part in which God is revealed to the prophet in the “still small voice.” The turn from divine absence to divine presence is articulated through two clear and powerful recollections of music that Elijah had sung in the oratorio’s First Part, a move that has the potential to reconfigure our evaluation of his role in the public and private spheres in those earlier passages. The second phase turns to Elijah’s own brief sojourn into the domestic realm, the widow’s scene, paying particular attention to the motivations that may have underlain the substantial revisions to the scene that took place between the Birmingham premiere and the London premiere the following year. The final phase explores the possibility that the widow and her son, the “surrogate family” in the oratorio, do not disappear after the widow’s scene, but linger on as “para-characters” with crucial roles in the unfolding drama.


2003 ◽  
Vol 773 ◽  
Author(s):  
C. Tamerler ◽  
S. Dinçer ◽  
D. Heidel ◽  
N. Karagûler ◽  
M. Sarikaya

AbstractProteins, one of the building blocks in organisms, not only control the assembly in biological systems but also provide most of their complex functions. It may be possible to assemble materials for practical technological applications utilizing the unique advantages provided by proteins. Here we discuss molecular biomimetic pathways in the quest for imitating biology at the molecular scale via protein engineering. We use combinatorial biology protocols to select short polypeptides that have affinity to inorganic materials and use them in assembling novel hybrid materials. We give an overview of some of the recent developments of molecular engineering towards this goal. Inorganic surface specific proteins were identified by using cell surface and phage display technologies. Examples of metal and metal oxide specific polypeptides were represented with an emphasis on certain level of specificities. The recognition and self assembling characteristics of these inorganic-binding proteins would be employed in develeopment of hybrid multifunctional materials for novel bio- and nano-technological applications.


2014 ◽  
Vol E97.C (5) ◽  
pp. 393-396
Author(s):  
Katsunori MAKIHARA ◽  
Mitsuhisa IKEDA ◽  
Seiichi MIYAZAKI

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