Filter cake characterization is very important in drilling and completion operations. Heterogeneity of the filter cake plays a key role in the design of chemical treatments needed to remove the filter cake. The objectives of this study are to characterize the filter cake under static and dynamic conditions, evaluate the using of polylactic acid and chelating agents to remove calcium carbonate-based filter cake, assess glycolic acid to remove Mn3O4-based filter cake, and evaluate ilmenite as a weighting material for water-based drilling fluid. In order to characterize the filter cake, computer tomography (CT) was used in combination with the scanning electronic microscopy (SEM) to analyze the filter cake. A modified HPHT filter cell was developed to perform the filtration tests. A see-through-cell was used to check the compatibility of different chemicals that were used to remove the filter cake. The results obtained from the CT scan showed that the filter cake was heterogeneous and contained two layers with different properties under static and dynamic conditions. Under static conditions, the formation of filter cake changed from compression to buildup; while under dynamic conditions, the filter cake was formed under continuous buildup. Polylactic acid was used as a component of the drilling fluid components and the results obtained showed that the drill-in fluid had stable rheological properties up to 250˚F over 24 hrs. The removal efficiency of the filter cake was nearly 100% and the return permeability was about 100% for Indiana limestone and Berea sandstone cores, when using a weight ratio of polylactic acid to calcium carbonate 3 to 1. GLDA (pH 3.3) and HEDTA (pH 4) can be used to remove the filter cake in one step without using α-amylase enzyme solutions. GLDA (20 wt% in a 200 g solution and pH of 3.3) and HEDTA (20 wt% in a 200 g solution and pH 4) had 100% removal efficiency of the filter cake using Indiana limestone and Berea sandstone cores. Chelate solutions, GLDA (pH of 3.3 - 13) and HEDTA (pH of 4 and 7) were incompatible with α-amylase enzyme solutions over a wide range of temperatures. CT results showed that no formation damage was observed when using chelating agents as a breaker to remove the calcium carbonate filter cake. Manganese tetraoxide-based filter cake had a removal efficiency of 85% after 20 hrs soaking with glycolic acid (5 wt%) after soaking with α-amylase for 24 hrs, and 89% after reaction with acid mixture (1 wt% HCl and 7 wt% glycolic acid) for 16 hrs. for both methods, the retained permeability was 100% for Indiana limestone cores and 120% for Berea sandstone cores, which indication maximum productivity of these formations. Ilmenite-based filter cake was ideal for HPHT applications, 0.2 in. thickness and 12 cm3 filtrate under dynamic conditions. The filtrate volume was reduced by adding a minor amount of CaCO3 solids that improved the particles packing. No sag problem was observed when using the micronized ilmenite in water-based drilling fluids. Ilmenite has a negative zeta potential in alkaline media and had a stable dispersion in water at pH > 7.

Percebe-se um interesse da indústria de fabricação de tintas na utilização de nanopartículas de prata devido às suas propriedades antimicrobianas. Neste trabalho, objetivou-se sintetizar e caracterizar soluções coloidais de nanopartículas de prata para ser um potencial aditivo antimicrobiano em tintas acrílicas à base d’água. No processo experimental, as nanopartículas de prata foram preparadas pela redução de íons de prata por boroidreto de sódio e estabilizada, utilizando citrato trissódico dihidrado. As caraterizações das nanopartículas de prata foram realizadas por espectroscopia de UV-Visível, microscopia eletrônica de transmissão e antibiograma contra bactérias Gram-positivas e Gram-negativas. Os espectros de UV-vis foram muito similares para as NPs Ag 18 ppm e para as NPs Ag 1000 ppm com os espectros de absorção na região de 400nm, que indica a presença de NPs Ag com forma esférica. Pela microscopia eletrônica de transmissão confirmou-se a presença das NPs Ag na forma esférica e observou-se a diferença de tamanho de partículas, sendo que para as NPs Ag a média foi de 7,32 nm e para NPs Ag 1000 ppm foi de 15,2 nm. O antibiograma demonstrou que as NPs Ag 18 ppm e de 1000 ppm apresentam atividade antibacteriana contra a bactéria Gram-negativa Escherichia coli e contra a bactéria Gram-positiva Staphylococcus aureus. No filme de tinta aplicado, avaliou-se a diferença de cor da tinta branca após a adição das NPs Ag, utilizando um espectrofotômetro e a perda de brilho após o ensaio de intemperismo acelerado sob radiação UV-B. Foi verificado que as NPs Ag não têm efeito sobre a perda de brilho do filme de tinta, porém induzem ao amarelamento do mesmo. Os resultados foram positivos para o ensaio de resistência a bactérias conforme a norma JIS Z 2801:2000 somente para as amostras de tinta acrílica à base d’água e verniz acrílico à base d’água com 100 ppm de NPs Ag. Para as amostras de tintas e vernizes com 3,6 ppm e 30 ppm de NPs Ag não houve efeito inibitório. Para o ensaio de resistência a fungos, segundo a norma ABNT NBR 14941, as tintas não apresentaram efeito inibitório satisfatório. / There is a particular interest of the paint manufacturing industry by using silver nanoparticles due its antimicrobial properties. This study has as objective to synthesize and characterize silver nanoparticles colloidal solutions as a potential antimicrobial additive in water-based acrylic paints. In the experimental process, the silver nanoparticles were prepared by reduction the silver ions by sodium borohydride and used trisodium citrate dihydrate as stabilizing agent. The characterizations of the silver nanoparticles were realized by spectroscopy in the infrared region, transmission electronic microscopy and Gram positive and Gram negative antibiograms. The UV-vis results were similar for the NPs Ag 18 ppm and NPs Ag 1000 ppm samples with the absorption spectra in the range of 400nm, which indicates the presence of de NPs Ag in a spherical format. By the transmission electron microscopy it was noted the presence of NPs Ag in a spherical format and differences in the particles sizes for NPs Ag (media of 7.32 nm) and for NPs Ag 1000 ppm (media of 15.2 nm) samples. The antibiogram test demonstrates that the 18 ppm and the 1000 ppm NPs Ag showed antibacterial activity against the Gram negative bacterium Escherichia coli and against the Gram positive bacteria Staphylococcus aureus. In the paint film, it was avaluated the difference of the white color after the incorporation of the NPs Ag using a spectrophotometer and the brightness lost after the UV-B accelerated weathering testing. It was noted that the NPs Ag had no effect in the brightness lost of the paint film; however inducing to the yellowing of the same. The results were positive for the bacterial resistances according to JIS Z 2801:2000 only for the water-based acrylic paints and varnish containing 100 ppm of NPs Ag. For the samples with 3,6 ppm and 30ppm it was not noted an inhibitory effect. Finally, for the fungal resistance according to ABNT NBR 14941 the paints do not showed satisfactory inhibitory effect.

Pesquisas sobre diferentes modelos de treinamento no meio aquático já demonstraram seus efeitos benéficos em diferentes capacidades físicas, bem como para a população com doenças metabólicas. Entretanto, para sujeitos portadores de síndrome metabólica (SM) são escassos os estudos que investigaram qual modelo de treinamento no meio aquático poderia gerar melhoras físicas e metabólicas. Assim, o objetivo do presente estudo foi comparar os efeitos neuromusculares e metabólicos de 12 semanas de treinamento aeróbio, treinamento de força e treinamento combinado no meio aquático em mulheres com SM. Foram selecionadas 51 mulheres, pós-menopáusicas, sedentárias e portadoras de SM que foram randomicamente divididas em três grupos de intervenção: hidro-aeróbica (HA; n=18; 63,77±5,03 anos), hidro-força (HF; n=16; 61,01±4,93 anos) e hidro-combinada (HC; n=17; 60,52±6,91). Uma sub-amostra participou de oito semanas sem prática de exercício físico para caracterizar um período controle. Os três grupos de intervenção realizaram duas sessões semanais de 60 minutos durante 12 semanas. Antes e após o período de treinamento foram realizadas análises sanguíneas, testes de força muscular, testes funcionais e questionário de qualidade de vida Para análise estatística foi utilizada o modelo de Equações de Estimativas Generalizadas (GEE) com post hoc de Bonferroni (α = 0,05). No período controle, nenhuma das variáveis avaliadas apresentou alteração significativa (p>0,05). Após o período de intervenção houve uma redução significativa da glicemia de jejum (HA: -7,6%; HF: -14,4%: HC: -14,0%), da pressão arterial sistólica (HA: -2,9%; HF: -8,5%: HC: -4,0%) e na contagem total dos fatores da SM (HA: -1,7%; HF: -6,7%: HC: -8,7%) sem diferença entre os grupos. Para a força muscular, houve um aumento significativo na força muscular dinâmica máxima de extensores de joelho (EJ) (HA: 29,6%; HF: 14,6%: HC: 26,7%) e flexores de cotovelo (FC) (HA: -0,1%; HF: 3,1%: HC: 7,4%), para a força resistente de EJ (HA: 25,2%; HF: 18,9%: HC: 23,8%) e FC (HA: 24,3%; HF: 16,6%: HC: 27,8%), para a contração isométrica voluntária máxima de EJ (HA: 11,0%; HF: 8,4%: HC: 26,4%), sem diferença entre os grupos de treinamento Para a atividade eletromiográfica (EMG) do reto femoral (RF) houve um aumento significativo apenas para o grupo HA (35,3%). A EMG de vasto lateral (VL) apresentou efeito significativo ao longo do tempo sem diferença entre os grupos (HA: 33,2%; HF: 40,4%: HC: 52,6%). Os testes funcionais apresentaram melhora significativa ao longo do tempo: Sentar e levantar (HA: 34,8%; HF: 29,0%: HC: 25,1%), Time-up-and-go (HA: -13,5%; HF: -11,8%: HC: -13,7%) sem diferença entre os grupos. A qualidade de vida apresentou aumento significativo no domínio físico (HA: 3,66%; HF: 3,88%: HC: 3,81%) sem diferença entre os grupos. Dessa forma, conclui-se que não houve diferenças expressivas entre os modelos de treinamento aeróbio, de força muscular ou combinado nas variáveis analisadas. Todos os treinamentos de hidroginástica foram eficientes para diminuir fatores da síndrome metabólica como a glicemia de jejum e a pressão arterial e para aumentar a força muscular dinâmica máxima, a força resistente e a força isométrica. Além disso, os treinamentos melhoraram a qualidade de vida e a capacidade funcional das mulheres. / Research about different training models in the aquatic environment has already demonstrated its beneficial effects on different physical capacities as well as for the population with metabolic diseases. However, for subjects with metabolic syndrome (MS) there are few studies that investigated which training model in the aquatic environment could generate physical and metabolic improvements. Thus, the aim of the present study was to compare the neuromuscular and metabolic effects of 12 weeks of aerobic training, strength training and combined training in the aquatic environment in women with MS. Fifty-one women, postmenopausal, sedentary and SM carriers were randomly divided into three intervention groups: hydro-aerobic (HA, n = 18, 63.77 ± 5.03 years), hydro-power (HP; N = 16, 61.01 ± 4.93 years) and hydro-combined (HC; n = 17; 60.52 ± 6.91). A subsample participated in eight weeks without physical exercise to characterize a control period. The three intervention groups performed two weekly sessions of 60 minutes for 12 weeks. Before and after the training period, blood tests, muscle strength tests, functional tests and a quality of life questionnaire were performed For statistical analysis, the Generalized Estimates Equations (GEE) model with Bonferroni post hoc (α = 0.05) was used. In the control period, none of the evaluated variables presented significant alteration (p> 0.005). After the intervention period there was a significant reduction of fasting blood glucose (HA: -7.6%, HP: -14.4%: HC: -14.0%), systolic blood pressure (HA: -2.9 HP: -8.5%: HC: -4.0%) and in the total counting of the factors of the SM (HA: -1.7%, HP: -6.7%: HC: -8.7% ) without difference between groups. For muscle strength, there was a significant increase in maximal dynamic muscle strength of knee extensors (KE) (HA: 29.6%, HP: 14.6%: HC: 26.7%) and elbow flexors (EF) (HA: -0.1%, HP: 3.1%: HC: 7.4%), for maximal repetitions of KE (HA: 25.2%, HP: 18.9%: H: 23.8% ) and EF (24.3%; HF: 16.6%: HC: 27.8%), for the maximum voluntary contraction of KE (HA: 11.0%, HP: 8.4% 26.4%), without difference between the training groups. For the electromyographic (EMG) activity of the rectus femoris (RF) there was a significant increase only for the HA group (35.3%). The vastus lateralis (LV) EMG showed significant effect over time with no difference between the groups (HA: 33.2%, HP: 40.4%: HC: 52.6%) The functional tests showed significant improvement over time: sitting and lifting (HA: 34.8%, HP: 29.0%: HC: 25.1%), Time-up-and-go (HA: 5%, HP: -11.8%: HC: -13.7%) without difference between groups. The quality of life showed a significant increase in the physical domain (HA: 3.66%, HP: 3.88%: HC: 3.81%) without difference between the groups. Thus, it was concluded that there were no significant differences between the aerobic training, muscle strength or combined models in the analyzed variables. All water-based training was efficient to decrease metabolic syndrome factors such as fasting blood glucose and blood pressure and to increase maximal dynamic muscle strength, endurance strength and isometric strength. In addition, training improved the quality of life and functional capacity of women.

Pesquisas sobre diferentes modelos de treinamento no meio aquático já demonstraram seus efeitos benéficos em diferentes capacidades físicas, bem como para a população com doenças metabólicas. Entretanto, para sujeitos portadores de síndrome metabólica (SM) são escassos os estudos que investigaram qual modelo de treinamento no meio aquático poderia gerar melhoras físicas e metabólicas. Assim, o objetivo do presente estudo foi comparar os efeitos neuromusculares e metabólicos de 12 semanas de treinamento aeróbio, treinamento de força e treinamento combinado no meio aquático em mulheres com SM. Foram selecionadas 51 mulheres, pós-menopáusicas, sedentárias e portadoras de SM que foram randomicamente divididas em três grupos de intervenção: hidro-aeróbica (HA; n=18; 63,77±5,03 anos), hidro-força (HF; n=16; 61,01±4,93 anos) e hidro-combinada (HC; n=17; 60,52±6,91). Uma sub-amostra participou de oito semanas sem prática de exercício físico para caracterizar um período controle. Os três grupos de intervenção realizaram duas sessões semanais de 60 minutos durante 12 semanas. Antes e após o período de treinamento foram realizadas análises sanguíneas, testes de força muscular, testes funcionais e questionário de qualidade de vida Para análise estatística foi utilizada o modelo de Equações de Estimativas Generalizadas (GEE) com post hoc de Bonferroni (α = 0,05). No período controle, nenhuma das variáveis avaliadas apresentou alteração significativa (p>0,05). Após o período de intervenção houve uma redução significativa da glicemia de jejum (HA: -7,6%; HF: -14,4%: HC: -14,0%), da pressão arterial sistólica (HA: -2,9%; HF: -8,5%: HC: -4,0%) e na contagem total dos fatores da SM (HA: -1,7%; HF: -6,7%: HC: -8,7%) sem diferença entre os grupos. Para a força muscular, houve um aumento significativo na força muscular dinâmica máxima de extensores de joelho (EJ) (HA: 29,6%; HF: 14,6%: HC: 26,7%) e flexores de cotovelo (FC) (HA: -0,1%; HF: 3,1%: HC: 7,4%), para a força resistente de EJ (HA: 25,2%; HF: 18,9%: HC: 23,8%) e FC (HA: 24,3%; HF: 16,6%: HC: 27,8%), para a contração isométrica voluntária máxima de EJ (HA: 11,0%; HF: 8,4%: HC: 26,4%), sem diferença entre os grupos de treinamento Para a atividade eletromiográfica (EMG) do reto femoral (RF) houve um aumento significativo apenas para o grupo HA (35,3%). A EMG de vasto lateral (VL) apresentou efeito significativo ao longo do tempo sem diferença entre os grupos (HA: 33,2%; HF: 40,4%: HC: 52,6%). Os testes funcionais apresentaram melhora significativa ao longo do tempo: Sentar e levantar (HA: 34,8%; HF: 29,0%: HC: 25,1%), Time-up-and-go (HA: -13,5%; HF: -11,8%: HC: -13,7%) sem diferença entre os grupos. A qualidade de vida apresentou aumento significativo no domínio físico (HA: 3,66%; HF: 3,88%: HC: 3,81%) sem diferença entre os grupos. Dessa forma, conclui-se que não houve diferenças expressivas entre os modelos de treinamento aeróbio, de força muscular ou combinado nas variáveis analisadas. Todos os treinamentos de hidroginástica foram eficientes para diminuir fatores da síndrome metabólica como a glicemia de jejum e a pressão arterial e para aumentar a força muscular dinâmica máxima, a força resistente e a força isométrica. Além disso, os treinamentos melhoraram a qualidade de vida e a capacidade funcional das mulheres. / Research about different training models in the aquatic environment has already demonstrated its beneficial effects on different physical capacities as well as for the population with metabolic diseases. However, for subjects with metabolic syndrome (MS) there are few studies that investigated which training model in the aquatic environment could generate physical and metabolic improvements. Thus, the aim of the present study was to compare the neuromuscular and metabolic effects of 12 weeks of aerobic training, strength training and combined training in the aquatic environment in women with MS. Fifty-one women, postmenopausal, sedentary and SM carriers were randomly divided into three intervention groups: hydro-aerobic (HA, n = 18, 63.77 ± 5.03 years), hydro-power (HP; N = 16, 61.01 ± 4.93 years) and hydro-combined (HC; n = 17; 60.52 ± 6.91). A subsample participated in eight weeks without physical exercise to characterize a control period. The three intervention groups performed two weekly sessions of 60 minutes for 12 weeks. Before and after the training period, blood tests, muscle strength tests, functional tests and a quality of life questionnaire were performed For statistical analysis, the Generalized Estimates Equations (GEE) model with Bonferroni post hoc (α = 0.05) was used. In the control period, none of the evaluated variables presented significant alteration (p> 0.005). After the intervention period there was a significant reduction of fasting blood glucose (HA: -7.6%, HP: -14.4%: HC: -14.0%), systolic blood pressure (HA: -2.9 HP: -8.5%: HC: -4.0%) and in the total counting of the factors of the SM (HA: -1.7%, HP: -6.7%: HC: -8.7% ) without difference between groups. For muscle strength, there was a significant increase in maximal dynamic muscle strength of knee extensors (KE) (HA: 29.6%, HP: 14.6%: HC: 26.7%) and elbow flexors (EF) (HA: -0.1%, HP: 3.1%: HC: 7.4%), for maximal repetitions of KE (HA: 25.2%, HP: 18.9%: H: 23.8% ) and EF (24.3%; HF: 16.6%: HC: 27.8%), for the maximum voluntary contraction of KE (HA: 11.0%, HP: 8.4% 26.4%), without difference between the training groups. For the electromyographic (EMG) activity of the rectus femoris (RF) there was a significant increase only for the HA group (35.3%). The vastus lateralis (LV) EMG showed significant effect over time with no difference between the groups (HA: 33.2%, HP: 40.4%: HC: 52.6%) The functional tests showed significant improvement over time: sitting and lifting (HA: 34.8%, HP: 29.0%: HC: 25.1%), Time-up-and-go (HA: 5%, HP: -11.8%: HC: -13.7%) without difference between groups. The quality of life showed a significant increase in the physical domain (HA: 3.66%, HP: 3.88%: HC: 3.81%) without difference between the groups. Thus, it was concluded that there were no significant differences between the aerobic training, muscle strength or combined models in the analyzed variables. All water-based training was efficient to decrease metabolic syndrome factors such as fasting blood glucose and blood pressure and to increase maximal dynamic muscle strength, endurance strength and isometric strength. In addition, training improved the quality of life and functional capacity of women.

Percebe-se um interesse da indústria de fabricação de tintas na utilização de nanopartículas de prata devido às suas propriedades antimicrobianas. Neste trabalho, objetivou-se sintetizar e caracterizar soluções coloidais de nanopartículas de prata para ser um potencial aditivo antimicrobiano em tintas acrílicas à base d’água. No processo experimental, as nanopartículas de prata foram preparadas pela redução de íons de prata por boroidreto de sódio e estabilizada, utilizando citrato trissódico dihidrado. As caraterizações das nanopartículas de prata foram realizadas por espectroscopia de UV-Visível, microscopia eletrônica de transmissão e antibiograma contra bactérias Gram-positivas e Gram-negativas. Os espectros de UV-vis foram muito similares para as NPs Ag 18 ppm e para as NPs Ag 1000 ppm com os espectros de absorção na região de 400nm, que indica a presença de NPs Ag com forma esférica. Pela microscopia eletrônica de transmissão confirmou-se a presença das NPs Ag na forma esférica e observou-se a diferença de tamanho de partículas, sendo que para as NPs Ag a média foi de 7,32 nm e para NPs Ag 1000 ppm foi de 15,2 nm. O antibiograma demonstrou que as NPs Ag 18 ppm e de 1000 ppm apresentam atividade antibacteriana contra a bactéria Gram-negativa Escherichia coli e contra a bactéria Gram-positiva Staphylococcus aureus. No filme de tinta aplicado, avaliou-se a diferença de cor da tinta branca após a adição das NPs Ag, utilizando um espectrofotômetro e a perda de brilho após o ensaio de intemperismo acelerado sob radiação UV-B. Foi verificado que as NPs Ag não têm efeito sobre a perda de brilho do filme de tinta, porém induzem ao amarelamento do mesmo. Os resultados foram positivos para o ensaio de resistência a bactérias conforme a norma JIS Z 2801:2000 somente para as amostras de tinta acrílica à base d’água e verniz acrílico à base d’água com 100 ppm de NPs Ag. Para as amostras de tintas e vernizes com 3,6 ppm e 30 ppm de NPs Ag não houve efeito inibitório. Para o ensaio de resistência a fungos, segundo a norma ABNT NBR 14941, as tintas não apresentaram efeito inibitório satisfatório. / There is a particular interest of the paint manufacturing industry by using silver nanoparticles due its antimicrobial properties. This study has as objective to synthesize and characterize silver nanoparticles colloidal solutions as a potential antimicrobial additive in water-based acrylic paints. In the experimental process, the silver nanoparticles were prepared by reduction the silver ions by sodium borohydride and used trisodium citrate dihydrate as stabilizing agent. The characterizations of the silver nanoparticles were realized by spectroscopy in the infrared region, transmission electronic microscopy and Gram positive and Gram negative antibiograms. The UV-vis results were similar for the NPs Ag 18 ppm and NPs Ag 1000 ppm samples with the absorption spectra in the range of 400nm, which indicates the presence of de NPs Ag in a spherical format. By the transmission electron microscopy it was noted the presence of NPs Ag in a spherical format and differences in the particles sizes for NPs Ag (media of 7.32 nm) and for NPs Ag 1000 ppm (media of 15.2 nm) samples. The antibiogram test demonstrates that the 18 ppm and the 1000 ppm NPs Ag showed antibacterial activity against the Gram negative bacterium Escherichia coli and against the Gram positive bacteria Staphylococcus aureus. In the paint film, it was avaluated the difference of the white color after the incorporation of the NPs Ag using a spectrophotometer and the brightness lost after the UV-B accelerated weathering testing. It was noted that the NPs Ag had no effect in the brightness lost of the paint film; however inducing to the yellowing of the same. The results were positive for the bacterial resistances according to JIS Z 2801:2000 only for the water-based acrylic paints and varnish containing 100 ppm of NPs Ag. For the samples with 3,6 ppm and 30ppm it was not noted an inhibitory effect. Finally, for the fungal resistance according to ABNT NBR 14941 the paints do not showed satisfactory inhibitory effect.

Percebe-se um interesse da indústria de fabricação de tintas na utilização de nanopartículas de prata devido às suas propriedades antimicrobianas. Neste trabalho, objetivou-se sintetizar e caracterizar soluções coloidais de nanopartículas de prata para ser um potencial aditivo antimicrobiano em tintas acrílicas à base d’água. No processo experimental, as nanopartículas de prata foram preparadas pela redução de íons de prata por boroidreto de sódio e estabilizada, utilizando citrato trissódico dihidrado. As caraterizações das nanopartículas de prata foram realizadas por espectroscopia de UV-Visível, microscopia eletrônica de transmissão e antibiograma contra bactérias Gram-positivas e Gram-negativas. Os espectros de UV-vis foram muito similares para as NPs Ag 18 ppm e para as NPs Ag 1000 ppm com os espectros de absorção na região de 400nm, que indica a presença de NPs Ag com forma esférica. Pela microscopia eletrônica de transmissão confirmou-se a presença das NPs Ag na forma esférica e observou-se a diferença de tamanho de partículas, sendo que para as NPs Ag a média foi de 7,32 nm e para NPs Ag 1000 ppm foi de 15,2 nm. O antibiograma demonstrou que as NPs Ag 18 ppm e de 1000 ppm apresentam atividade antibacteriana contra a bactéria Gram-negativa Escherichia coli e contra a bactéria Gram-positiva Staphylococcus aureus. No filme de tinta aplicado, avaliou-se a diferença de cor da tinta branca após a adição das NPs Ag, utilizando um espectrofotômetro e a perda de brilho após o ensaio de intemperismo acelerado sob radiação UV-B. Foi verificado que as NPs Ag não têm efeito sobre a perda de brilho do filme de tinta, porém induzem ao amarelamento do mesmo. Os resultados foram positivos para o ensaio de resistência a bactérias conforme a norma JIS Z 2801:2000 somente para as amostras de tinta acrílica à base d’água e verniz acrílico à base d’água com 100 ppm de NPs Ag. Para as amostras de tintas e vernizes com 3,6 ppm e 30 ppm de NPs Ag não houve efeito inibitório. Para o ensaio de resistência a fungos, segundo a norma ABNT NBR 14941, as tintas não apresentaram efeito inibitório satisfatório. / There is a particular interest of the paint manufacturing industry by using silver nanoparticles due its antimicrobial properties. This study has as objective to synthesize and characterize silver nanoparticles colloidal solutions as a potential antimicrobial additive in water-based acrylic paints. In the experimental process, the silver nanoparticles were prepared by reduction the silver ions by sodium borohydride and used trisodium citrate dihydrate as stabilizing agent. The characterizations of the silver nanoparticles were realized by spectroscopy in the infrared region, transmission electronic microscopy and Gram positive and Gram negative antibiograms. The UV-vis results were similar for the NPs Ag 18 ppm and NPs Ag 1000 ppm samples with the absorption spectra in the range of 400nm, which indicates the presence of de NPs Ag in a spherical format. By the transmission electron microscopy it was noted the presence of NPs Ag in a spherical format and differences in the particles sizes for NPs Ag (media of 7.32 nm) and for NPs Ag 1000 ppm (media of 15.2 nm) samples. The antibiogram test demonstrates that the 18 ppm and the 1000 ppm NPs Ag showed antibacterial activity against the Gram negative bacterium Escherichia coli and against the Gram positive bacteria Staphylococcus aureus. In the paint film, it was avaluated the difference of the white color after the incorporation of the NPs Ag using a spectrophotometer and the brightness lost after the UV-B accelerated weathering testing. It was noted that the NPs Ag had no effect in the brightness lost of the paint film; however inducing to the yellowing of the same. The results were positive for the bacterial resistances according to JIS Z 2801:2000 only for the water-based acrylic paints and varnish containing 100 ppm of NPs Ag. For the samples with 3,6 ppm and 30ppm it was not noted an inhibitory effect. Finally, for the fungal resistance according to ABNT NBR 14941 the paints do not showed satisfactory inhibitory effect.

O uso de tintas à base de solventes tem acarretado problemas ambientais, gerando a necessidade de pesquisas para o desenvolvimento de materiais com baixo teor de compostos orgânicos voláteis (VOC) para redução do impacto ao meio ambiente. Os efeitos do VOC ao meio ambiente motivaram este estudo, que tem como objetivos desenvolver uma nova tinta de base aquosa para a aplicação na fabricação de volantes automotivos. O presente trabalho tem como objetivo estudar o desempenho por meio de medição de camada de tinta, resistência aos reagentes químicos, combustibilidade e resistência ao desgaste da pintura obtida com tintas baseadas em 1) solventes orgânicos e 2) água, aplicadas em volantes automotivos constituídos de poliuretano (PU). Os resultados demonstram que a pintura à base de água possui uma espessura de camada maior e menor velocidade de combustão em relação à pintura à base de solventes orgânicos, porém apresenta um menor desempenho no ensaio de resistência à abrasão e aos reagentes químicos em relação à tinta à base de solventes orgânicos. / The use of solvent-based paints has caused environmental problems, creating the need for research to develop materials with low volatile organic compound (VOC) to reduce the environmental impact. The effect of volatile organic compound (VOC) to the environment motivated this study, which aims to develop a new water-based paint for application in the manufacture of automotive steering wheels. The present work aim to study the performance by measuring the layer thickness, resistance to chemical reagents, combustibility and wear resistance obtained with paints based on 1) organic solvents and 2) water, applied in automotive steering wheels made of polyurethane (PU). The results has showed that water-based paint has a layer thickness greater and lower burning rate than solvent-based paint, but it has a lower performance in the test for resistance to abrasion and resistance to chemical reagents in relation to organic solvent-based paint.

Improvement properties of building materials are essential. In this dissertation thesis, the main concern had been on synthesizing a new resin to improve the properties of concrete and brick. Solvent-based polymers have been used for many years to improve the quality of building materials. In contrast to solvent-based polymers, water-based emulsion polymers are one of the available solutions that have been used to improve the quality of building materials. Several advantages can be enumerated for water-based emulsion polymers such as lower volatile organic compounds (VOC), easier application, lower carbon dioxide emissions in the production, and fossil resource preservation. Water-based emulsion polymers are synthesized from simple homopolymers to copolymers with various monomers and additives. In this research, the synthesis and characterization of water-based acrylic styrene emulsion copolymer had been the main concern. Acrylic monomers could develop the qualities such as thermoplasticity, water solubility, and a longer lifespan of the polymer, while styrene monomers will impart water resistance and stiffness properties. In this research, the first step had been the synthesis of a water-based emulsion copolymer. Furthermore, considering the importance of biodegradability of the synthesized copolymer, the research followed by the replacement of ingredients such as emulsifiers with higher biodegradability characteristics with eco-friendly by-products, i.e. reducing the microplastic hazards. As a result, the copolymer could be decomposed better, and consequently, problems with the release of microplastics will be reduced. The synthesized water-based acrylic styrene emulsion copolymer was characterized by FTIR, DSC, and TGA. The FTIR results confirmed successful emulsion polymerization of acrylic styrene copolymer. DSC results confirmed the formation of an amorphous thermoplastic type of copolymer with a single glass transition temperature. The TGA result also confirms a single decomposition temperature. The film formation was carried out using a film applicator to evaluate the film formation properties. The substitution of the superseded emulsifiers (both anionic and nonionic) did not alter the characteristics of the synthesized copolymer, while some of the qualities such as water absorbance of the dried copolymer are improved (a water absorption test was carried out). To improve the quality of both synthesized emulsion copolymers (with conventional and superseded emulsifiers), the nanocomposite of the emulsion copolymer was prepared (Cloisite 30B at a concentration of 0.2 to 1 %). The synthesized nanocomposite showed better water resistance in the coating application in contrast with emulsion copolymer. The next stage of the research has been concentrated on the application of the synthesized water-based emulsion copolymer to building materials (concrete and brick). The synthesis copolymer has been applied as a coating on the surface of the concrete and bricks. Moreover, the synthesis copolymer was used as one of the ingredients in the mixture of the concrete. The promising results for the coating improved when the synthesis polymer was modified with nanoparticles (Cloisite 30B at a concentration of 1 % weight of the latex). Incorporating the synthesized copolymer in the mixture of concrete caused decreasing in the density of concrete by 4 % ( via air voids formation mechanism). However, water absorption was improved when synthesized copolymer was mixed with the concrete. The synthesized copolymer and the nanocomposite is a suitable coating for the concrete and brick. Furthermore, this copolymer is a suitable water-based coating with improved properties in building materials.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19737号 / 工博第4192号 / 新制||工||1646(附属図書館) / 32773 / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 阿部 竜, 教授 陰山 洋, 教授 田中 庸裕 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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