Diamond is widely known for its extraordinary properties, such as high hardness, thermal conductivity, electron mobility, energy bandgap and durability making it a very attractive material for many applications. Synthetic diamonds retain most of the attractive properties of natural diamond. Among the types of synthetic diamonds, nanocrystalline diamond (NCD) is being developed for electrical, tribological, optical, and biomedical applications. In this research work, NCD films were grown by the pulsed electron beam ablation (PEBA) method at different process conditions such as accelerating voltage, pulse repetition rate, substrate material and temperature. PEBA is a relatively novel deposition technique, which has been developed to provide researchers with a new means of producing films of equal or better quality than more conventional methods such as Pulsed Laser Deposition, Sputtering, and Cathodic Vacuum Arc. The deposition process parameters have been defined by estimating the temperature and pressure of the plasma particles upon impact with the substrates, and comparing the data with the carbon phase diagram. Film thickness was measured by visible reflectance spectroscopy technique and was in the range of 40 – 230 nm. The nature of chemical bonding, namely, the ratio (sp3/sp3+sp2) and nanocrystallinity percentage were estimated using visible Raman spectroscopy technique. The films prepared from the ablation of a highly ordered pyrolytic graphite (HOPG) target on different substrates consisted mainly of nanocrystalline diamond material in association with a diamond-like carbon phase. The micro-structural properties and surface morphology of the films were studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The mechanical properties of the NCD films were evaluated by nano-indentation.

A gelatina (GEL) é um biopolímero biodegradável e biocompatível que forma naturalmente coloides semissólidos ou hidrogéis em soluções aquosas. Sendo um polímero hidrofílico, a GEL possui propriedades estruturais e físico-mecânicas que a distinguem de polímeros hidrofílicos sintéticos. São essas características que inspiraram o desenvolvimento do presente trabalho. Para analisa-las foram desenvolvidos filmes e hidrogéis de GEL utilizando radiação ionizante mediante diferentes técnicas: irradiação por 60Co, feixe de elétrons (EB) e/ou EB pulsado. Na elaboração de filmes a base de GEL foram incorporados diferentes aditivos, tais como glicerol (GLY), álcool polivinílico (PVA), hidroxitolueno butilado (BHT), acrilamida e/ou fibra vegetal. Esse produto filmes a base de GEL foi analisado quanto às suas propriedades mecânicas, cor, absorção de água, entre outros; e irradiado com doses de 10 a 60 kGy, dependendo do aditivo. Na síntese radioinduzida de nano-hidrogéis de GEL, polietileno glicol (PEG) e a mistura (MIX) de ambos os aditivos, GEL e PEG, foram analisados a dimensão, massa molar e morfologia das nanopartículas. Houve aumento significativo da fração gel com o aumento da dose de radiação nas amostras de GEL/fibra. Os filmes a base de GEL com 10% PVA irradiados a 20 kGy apresentaram a maior resistência à perfuração. A adição de antioxidante BHT influenciou em algumas das propriedades dos filmes a base de GEL nas condições aplicadas. Em relação aos nano-hidrogéis houve redução do raio hidrodinâmico da MIX irradiada com 60Co de 68 ± 25 nm (2 kGy) para 35 ± 4 nm (5 kGy). Tanto nos filmes quanto nos nano-hidrogéis de GEL, a radiação mostrou ser uma ferramenta conveniente na modificação de materiais poliméricos. / The gelatin (GEL) is a biocompatible and biodegradable biopolymer, which naturally forms semi-solid colloids or hydrogels in aqueous solutions. As a hydrophilic polymer, the GEL has structural and physico-mechanical properties that distinguish it from synthetic hydrophilic polymers. The study of these properties led to the development of the present work. Thus, GEL-based films and hydrogels were developed using ionizing radiation technology by different techniques: irradiation with 60Co, electron beam (EB) and/or pulsed EB. The GEL based-films enriched with different additives, such as glycerol (GLY), polyvinyl alcohol (PVA), butylated hydroxytoluene (BHT), acrylamide and/or vegetal fiber, were irradiated with doses from 10 to 60 kGy, depending on the additive; some parameters like mechanical properties, color, and water absorption were analyzed. In the radio-induced synthesis of GEL nanohydrogels, polyethylene glycol (PEG) and the mixture (MIX) of additives, PEG and GEL, the size, molar mass and surface morphology of the nanohydrogels were analyzed. There was a significant increase of gel fraction with increase of the radiation dose for the GEL/fiber samples. The GEL based-films with 10% PVA irradiated at 20 kGy showed the highest puncture strength. The addition of antioxidant BHT affected on some GEL based-films properties on applied conditions. Regarding the nanohydrogels, there was a decrease of hydrodynamic radius of MIX irradiated with 60Co from 68 ± 25 nm (2 kGy) to 35 ± 4 nm (5 kGy). The radiation proved to be a convenient tool in the modification of polymeric materials for both, GEL films and hydrogels.

A gelatina (GEL) é um biopolímero biodegradável e biocompatível que forma naturalmente coloides semissólidos ou hidrogéis em soluções aquosas. Sendo um polímero hidrofílico, a GEL possui propriedades estruturais e físico-mecânicas que a distinguem de polímeros hidrofílicos sintéticos. São essas características que inspiraram o desenvolvimento do presente trabalho. Para analisa-las foram desenvolvidos filmes e hidrogéis de GEL utilizando radiação ionizante mediante diferentes técnicas: irradiação por 60Co, feixe de elétrons (EB) e/ou EB pulsado. Na elaboração de filmes a base de GEL foram incorporados diferentes aditivos, tais como glicerol (GLY), álcool polivinílico (PVA), hidroxitolueno butilado (BHT), acrilamida e/ou fibra vegetal. Esse produto filmes a base de GEL foi analisado quanto às suas propriedades mecânicas, cor, absorção de água, entre outros; e irradiado com doses de 10 a 60 kGy, dependendo do aditivo. Na síntese radioinduzida de nano-hidrogéis de GEL, polietileno glicol (PEG) e a mistura (MIX) de ambos os aditivos, GEL e PEG, foram analisados a dimensão, massa molar e morfologia das nanopartículas. Houve aumento significativo da fração gel com o aumento da dose de radiação nas amostras de GEL/fibra. Os filmes a base de GEL com 10% PVA irradiados a 20 kGy apresentaram a maior resistência à perfuração. A adição de antioxidante BHT influenciou em algumas das propriedades dos filmes a base de GEL nas condições aplicadas. Em relação aos nano-hidrogéis houve redução do raio hidrodinâmico da MIX irradiada com 60Co de 68 ± 25 nm (2 kGy) para 35 ± 4 nm (5 kGy). Tanto nos filmes quanto nos nano-hidrogéis de GEL, a radiação mostrou ser uma ferramenta conveniente na modificação de materiais poliméricos. / The gelatin (GEL) is a biocompatible and biodegradable biopolymer, which naturally forms semi-solid colloids or hydrogels in aqueous solutions. As a hydrophilic polymer, the GEL has structural and physico-mechanical properties that distinguish it from synthetic hydrophilic polymers. The study of these properties led to the development of the present work. Thus, GEL-based films and hydrogels were developed using ionizing radiation technology by different techniques: irradiation with 60Co, electron beam (EB) and/or pulsed EB. The GEL based-films enriched with different additives, such as glycerol (GLY), polyvinyl alcohol (PVA), butylated hydroxytoluene (BHT), acrylamide and/or vegetal fiber, were irradiated with doses from 10 to 60 kGy, depending on the additive; some parameters like mechanical properties, color, and water absorption were analyzed. In the radio-induced synthesis of GEL nanohydrogels, polyethylene glycol (PEG) and the mixture (MIX) of additives, PEG and GEL, the size, molar mass and surface morphology of the nanohydrogels were analyzed. There was a significant increase of gel fraction with increase of the radiation dose for the GEL/fiber samples. The GEL based-films with 10% PVA irradiated at 20 kGy showed the highest puncture strength. The addition of antioxidant BHT affected on some GEL based-films properties on applied conditions. Regarding the nanohydrogels, there was a decrease of hydrodynamic radius of MIX irradiated with 60Co from 68 ± 25 nm (2 kGy) to 35 ± 4 nm (5 kGy). The radiation proved to be a convenient tool in the modification of polymeric materials for both, GEL films and hydrogels.