Recent Patents on Materials Science
Volume 1, 3 Issues 2008
ISSN: 1874-4648 (Print)
ISSN: 1874-4656 (Online)
Recent Patents on Materials
Science
Volume 1, Number 2, June 2008
Contents
Recent Patents on the Optical Resolution of Amino
Acid Enantiomers by Crystallization from Solution
Pp. 98-115
Adrian E. Flood
[Abstract]
Superparamagnetic Magnetite (Fe3O4)
Nanoparticles for Bio-Applications Pp. 116-127
Peter Majewski and Benjamin Thierry
[Abstract]
Recent Patents and Developments in Biocidal Wood
Protection Systems for Exterior Applications
Pp. 128-134
Tor P. Schultz, Darrel D. Nicholas and Craig R. McIntyre
[Abstract]
Manufacturing of Orthodontic Brackets: A Review
of Metallurgical Perspectives and Applications Pp.
135-139
Theodore Eliades, Spiros Zinelis, Christoph Bourauel and
Georgeb Eliades
[Abstract]
Thermally Sprayed Thermal Barrier Coating (TBC)
Systems: A Survey of Recent Patents Pp. 140-158
Hans D. Lehmann and Robert B. Heimann
[Abstract]
Industrial Applications of Microemulsions: A
Patent Review Pp. 159-164
Vikas Bali, Bhavna, Mushir Ali, Sanjula Baboota and Javed
Ali
[Abstract]
Titanium Oxide Based Photocatalysts: From Research
to Applications Pp. 165-175
Lianzhou Wang and Gao Q. (Max) Lu
[Abstract]
Patent Selections Pp. 176-178
Abstracts
[Back to top]
Recent Patents on the Optical Resolution of Amino
Acid Enantiomers by Crystallization from Solution
Adrian E. Flood
Amino acids are a significant class of compounds in a
number of different application areas, including pharmaceuticals,
nutrition, and nonlinear optical materials. Nearly all amino
acids are chiral molecules, and appear in D- and L-forms (enantiomers)
which are mirror images of each other and thus share the same
chemical properties (if they do not interact with another
chiral molecule), apart from their optical rotation. Although
the α-amino
acids are ubiquitous in natural materials, industrially it
is more convenient to produce them with chemical syntheses,
which typically are not specific to a desired enantiomer and
therefore produce a racemic mixture having equal quantities
of the two enantiomers. In most applications of the materials
a pure enantiomeric form is required and thus the racemic
mixture must be separated into its component enantiomers,
a process which is typically known as optical resolution.
Optical resolution is often a difficult process because the
components separated have identical properties, however a
range of ingenious techniques has been developed to perform
the resolution. This article reviews the patented techniques
to achieve optical resolution of amino acids using methods
involving crystallization from solution. These methods represent
the most industrially significant resolution methods, in particular
preferential crystallization and crystallization of diastereomer
salts. A short summary of several types of techniques not
using crystallization is also presented.
[Back to top]
Superparamagnetic Magnetite (Fe3O4)
Nanoparticles for Bio-Applications
Peter Majewski and Benjamin Thierry
During the last decades, magnetite nanoparticles have
been in the focus of a tremendous amount of research due to
their biocompatibility and excellent magnetic properties,
and numerous applications have been reported. Importantly,
advances in the synthesis of magnetite nanoparticles enable
excellent control over their size, shape and composition.
However, despite remarkable progresses in controlling the
synthesis, functionalization and application of magnetite
nanoparticles, many issues remain to be overcome for these
nanotechnology-products to revolution the medical practice.
The fine control and application of colloidal nanostructures
such as magnetite nanoparticles in complex biological systems
remains especially challenging. This article reviews the current
literature and patent base of magnetite nanoparticle’s
preparation and use, with a special emphasis on biomedical
applications. The articles refers to the US patent numbers
4452773, 4554088, 4628037, 4654267, 4672040, 4695392, 4695393,
4770183, 4795698, 4827945, 4951675, 5069216, 5219554, 5262176,
5314679, 5759793, 6048515, 6203777, 6207133, 6,479033, 6479146,
6514481, 6576221, 6599498, 6767635, 6773812, 6962685, 6997863,
7074175, 7128891, 7147742, 7175912, 7208134, and 7273580,
as well as European patent number EP1494028.
[Back to top]
Recent Patents and Developments in Biocidal Wood Protection
Systems for Exterior Applications
Tor P. Schultz, Darrel D. Nicholas and Craig R. McIntyre
Wood products used in outdoor applications are treated
with biocides to prevent biodegradation by many different
fungi and insects. Environmental and disposal concerns have
resulted in a rapid and dramatic worldwide shift from the
older first-generation preservatives to copper-based systems
for residential applications, where the copper(II) is complexed
with an organic amine. In the last year the alkaline amine
formulation has been partially replaced by microdispersed
copper systems that offer several advantages. The current
trend in wood preservation is directed towards combining two
or more organic biocides in a waterborne formulation employing
relatively benign and expensive agrochemicals, with non-biocidal
additives sometimes added for increased efficacy and/or other
benefits. This review discusses the patents and developments
in the past 10 years in biocidal waterborne or solventborne
wood protection systems for pressure-treating solid or composite
wood products in exterior above-ground or ground-contact applications.
Only totally organic systems and related recent developments
are discussed, with the exception of microdispersions to formulate
both metallic and organic systems.
[Back to top]
Manufacturing of Orthodontic Brackets: A Review of Metallurgical
Perspectives and Applications
Theodore Eliades, Spiros Zinelis, Christoph Bourauel and
George Eliades
Orthodontic brackets comprise the basic medium of transmission
of force to teeth in orthodontics; this is achieved by the
development of loads from activated archwire into the bracket
slot. As a standard manufacturing process, brazing alloys
to join the base and wing components of brackets are adopted
by the industry. Some of these alloys also contain traces
of the cytotoxic cadmium, which is added to lower the melting
temperature and improve wetting. Moreover, silver-based brazing
alloys form a galvanic couple that can lead to ionic release,
mainly copper and zinc. Corrosion, which has been substantially
minimized in current materials, is the main reason for the
progressive dissolution of brazing filler metal, leading to
detachment of the wing from the bracket base during orthodontic
therapy or at the debonding stage. To overcome this problem,
several manufacturers have introduced gold-based brazing materials
that might lead to the dissolution of stainless steel, because
of the formation of the galvanic couple. Thus, although brazing
alloys can facilitate the manufacturing of brackets with alloys
of certain properties, e.g., a stiffer alloy for
the wing to withstand the loads from activated wires and a
softer alloy for the base to facilitate a peel-off effect
during debonding-they have several problems.
Laser welding was relatively recently introduced in bracket
manufacturing as an alternative to alloy soldering. With this
method, welding of the wing to the base does not extend to
the bulk material, and thus a “surface seal” is
formed that is confined to the periphery of the joint. This
technique eliminates the intermediate phases such as soldering
alloys and shows acceptable mechanical performance with a
low risk of joint failure.
The metal injection molding (MIM) process, which has significantly
expanded during the past few years, involves mixing metal
powders with particle sizes of a few microns with organic
binders, lubricants, and dispersants to obtain a homogeneous
mixture. Injection of the feedstock is performed by using
an injection-molding machine, similar to that used in the
plastics industry. MIM-manufactured products are one-piece
appliances with tolerances of the desired dimensions of approximately
0.3% and density values more than 97% of the theoretical density
of the material. Porosity is a known defect of MIM parts,
with adverse effects on the mechanical and corrosion resistance
of most MIM-manufactured products. The hardness of the MIM-made
brackets tested varied from 154 to 287 HV, a value much lower
than the hardness of wing components of conventional stainless
steel brackets, introducing the problems associated with soft
and compliant wing components, as noted previously.
This paper reviews the available evidence recent patent on
bracket manufacturing with specific reference to limitations
of each method from metallurgical and application perspectives.
[Back to top]
Thermally Sprayed Thermal Barrier Coating
(TBC) Systems: A Survey of Recent Patents
Hans D. Lehmann and Robert B. Heimann
The continuing quest for increased combustion temperatures
within aerospace gas turbines has led to a flurry of R&D
activities. The contribution is aimed at providing insight
into most recent developments in terms of materials selection,
processing technologies, in-service performance, and application
of heat-insulating ceramics with (1) high melting point, (2)
low coefficient of thermal conductivity, (3) high coefficient
of thermal expansion, (4) resistance to solid particle erosion
(SPE), (5) high thermal shock resistance, and (6) oxidation
resistance. The survey of patented research in the area of
thermal barrier coatings described below covers the period
from 2006 to early 2008 even though several earlier patents
have also been considered when appropriate.
[Back to top]
Industrial Applications of Microemulsions: A Patent Review
Vikas Bali, Bhavna, Mushir Ali, Sanjula Baboota and Javed
Ali
Since the inception of the concept of microemulsions
by Hoar and Schulman in 1940, they have always been a key
area of interest, both in terms of basic research as well
as in industry, which is primarily due to their unique characteristics
like thermodynamic stability, optical clarity, and ease of
preparation. The existence of microdomains of different polarity
with in the same, single-phase solution enables both water-soluble
and oil-soluble materials to be solubilized, at the same time.
Thus, owing to these features, the uses and applications of
microemulsions have been numerous. It is, thus, the objective
of this review to summarize the industrial applications of
these novel surfactant systems by discussing the patents governing
various applications of these systems.
[Back to top]
Titanium Oxide Based Photocatalysts: From Research to Applications
Lianzhou Wang and Gao Q. (Max) Lu
The increasing concerns for climate change and exhausting
supply of traditional energy sources have triggered world-wide
research efforts in developing alternative energy generation
systems. Photocatalytic process for clean electricity/H2
generation and environmental pollution purification has been
considered as one of the most promising solutions to address
these key challenges that mankind faces. Among various semiconducting
photocatalysts, TiO2 has
been recognized as the best candidate to date. In this review,
we first introduce the basic mechanisms of photocatalytic
reactions addressing the processes of electron-hole generation,
recombination, charge transfer and surface redox reactions;
followed by the preparation of nanostructured TiO2
and their band-gap/surface modification towards visible light
response photocatalytic activity, with a main focus on representative
research works and patenting activities. The second part overviews
some typical applications of TiO2
which include water splitting for H2
production, air and water pollutant purification, self-cleaning
coating and dye-sensitized solar cells. Directing the future
scientific and applied research efforts toward rational design
of this photocatalyst will play a key role in achieving efficient
utilization of solar energy for environmental and energy conversion
applications.
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