Environmental biomaterials

XPS has been used in almost every area in which the properties of surfaces are important. The most prominent areas can be deduced from conferences on surface analysis, especially from ECASIA, which is held every two years. These areas are adhesion, biomaterials, catalysis, ceramics and glasses, corrosion, environmental problems, magnetic materials, metals, micro- and optoelectronics, nanomaterials, polymers and composite materials, superconductors, thin films and coatings, and tribology and wear. The contributions to these conferences are also representative of actual surface-analytical problems and studies [2.33 a,b]. A few examples from the areas mentioned above are given below more comprehensive discussions of the applications of XPS are given elsewhere [1.1,1.3-1.9, 2.34—2.39]. 

The increased importance of renewable resources for raw materials and recyclability or biodegradability of the material at the end of its useful life is demanding a shift from petroleum-based synthetics to agro-based materials in industrial applications. Increased social awareness of environmental problems posed by the non-degradable, non-recyclable content of their products is forcing manufacturers to enhance the biodegradable content, which in turn favors a switch to biomaterials [1]. 

Eaust RA (1994) Toxicity summary for toluene, Oak Ridge reservation environmental restoration program. Available at http //rais.oml.gov/tox/profiles/toluene f Vl.shtml Eear NT, Roman E, Reeves G, Panneft B (1998) Childhood cancer and paternal employment in agriculture The role of pesticides. Br J Cancer 77 825-829 Eemandez-Urrusuno R, Eattal E, Eeger J, Couvreur P, Therond P (1997) Evaluation of hepatic antioxidant systems after intravenous administration of polymeric nanoparticles. Biomaterials 18 511-517... 

Aliphatic polyesters occupy a key position in the field of polymer science because they exhibit the remarkable properties of biodegradability and biocompatibihty, which opens up a wide range of applications as environmentally friendly thermoplastics and biomaterials. Three different mechanisms of polymerization can be implemented to synthesize aliphatic polyesters (1) the ring-opening polymerization (ROP) of cyclic ketene acetals, (2) the step-growth polymerization of lactones, and (3) the ROP of lactones (Fig. 1). 

Raman spectroscopy can be used for live, in situ, temporal studies on the development of bone-like mineral (bone nodules) in vitro in response to a variety of biomaterials/scaffolds, growth factors, hormones, environmental conditions (e.g. oxygen pressure, substrate stiffness) and from a variety of cell sources (e.g. stem cells, FOBs or adult osteoblasts). Furthermore, Raman spectroscopy enables a detailed biochemical comparison between the TE bone-like nodules formed and native bone tissue. Bone formation by osteoblasts (OB) is a dynamic process, involving the differentiation of progenitor cells, ECM production, mineralisation and subsequent tissue remodelling. 

Al Rmalli, S.W., Harrington, C.F., Ayub, M. and Haris, P.I. (2005) A biomaterial based approach for arsenic removal from water. Journal of Environmental Monitoring, 7(4), 279-82. 

Extraction with supercritical CO2 is a technical process of increasing importance. It provides a mild and rapid technique for the extraction of low- or medium-polarity substances. Supercritical CO2 is used for supercritical fluid extraction (SFE) in important technical processes such as the decaffeination of coffee and the extraction of hops, as well as the extraction of naturally occurring compounds from biomaterials. As many applications are performed in the pharmaceutical, polymer, environmental and nutritional fields, direct on-line SFE-NMR would be an ideal tool to monitor the various extraction processes. 

The shift from bio-based specialties to commodities is already visible in the marketplace with biopolymers made from corn. The first example is NatureWorks from Cargill, which is made from corn sugar-derived lactic acid. As in the biochemicals examples described above, the environmental benefits are eye-opening NatureWorks already requires 25 to 55 percent less fossil resources, and it is planned to replace fossil resources completely in the next four to six years (Euro-paBio and McKinsey Company, 2003). Other high-potential biomaterials are a polymer based on 1,3-propanediol from DuPont and Genencor (Sorona ) and... 

Improved Environmental Stability oe the Biomaterial 3.5.4.1 Thermo Gravimetric Analysis... 

The increased stability of the graft copolymerized biomaterial has been monitored on the basis of an increase in the number of regeneration cycles. Structurally modified biomaterial (polymerized) could be used up to six times as compared to only four times of unmodified biomaterial, thereby exhibiting the increased environmental stability of the polymerized biosorbent (Table 3.3). 

Despite the novel positive acquisitions of knowledge from experimental and theoretical studies of gas-phase elemental mercury chemistry there are still large gaps before a complete imderstanding of the fate of mercury in the atmosphere is obtained. It is essential to provide kinetic data and information about formed products. There are some limited studies on the kinetics of gas-phase elemental mercury oxidation on surfaces [68-70]. However, experimental studies on uptake or kinetics of heterogeneous reactions of mercury on various environmentally relevant surfaces such as ice, snow, and aerosols and biomaterials, are needed. 

Lastly we examine attempts to design structures for particular functions, namely, films that act as barriers and capsules that contain bioactive substances. In the future, we will need to create novelty in the long-term stability of products and delivery of specific molecules for a health benefit. These technologies are attracting attention not only from the food industry but also for nonfood use. Sustainable and environmentally friendly attributes of biomaterials are increasingly discussed, compared to petrochemically derived, synthetic polymers and plastics. For once, food materials scientists can teach other industries the rules of the game. ... 

Polymeric biomaterials play the vital roles of guiding/controlling the growth of the new tissue and protecting the immature tissue from environmental stresses. 

In contrast to lipids, polymer chemistry allows various chemical modifications to introduce functionality and make polymers responsible to environmental stimuli (pH, temperature, ions, light, etc.). In biosciences, responsiveness to external stimuli is a crucial factor, especially in drug release and construction of biomaterials. 

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