11 research outputs found
Autogestão e subjetividade: interfaces e desafios na visão de especialistas da ANTEAG, UNISOL e UNITRABALHO
A Administração, em sua corrente teórica dominante, tem se prestado a transformar as empresas em espaços de propagação ideológica acerca de formas hierarquizadas de organização e gestão do trabalho. Negando esta dimensão política e ideológica da ação administrativa, a Teoria da Administração tem se tornado cúmplice dos interesses do business, educando profissionais cujas ações acabam sobrepondo o econômico ao fator humano e às questões éticas. Em contraposição a este cenário de injustiça e exploração, encontra-se a autogestão, forma de gestão não hierarquizada e democrática cuja implantação tem enfrentado muita dificuldade. Para buscar compreender os desafios que se impõem aos trabalhadores e trabalhadoras que se propõem a trabalhar de maneira autogestionária, foram realizadas entrevistas semi-estruturadas com um especialista em cada uma das três seguintes entidades de fomento a organizações autogestionárias: ANTEAG, UNISOL e UNITRABALHO. Os dados foram analisados por meio do método de análise de conteúdo e indicaram que a autogestão, na visão destes profissionais, implica necessidade de uma mudança de subjetividade desses trabalhadores e trabalhadoras, acostumados ao modelo de trabalho hierarquizado e não democrático. Com base nisso, argumenta-se que, para uma melhor compreensão da dificuldade de implantação da autogestão nas organizações, é necessária a adoção de um conceito de subjetividade que englobe não só o seu caráter individual, mas também seu caráter coletivo. Conquanto a visão da subjetividade individual e coletiva nos leve a refletir sobre o fato de que os desafios da prática da autogestão são mais profundos do que aparentam inicialmente, acreditamos que sua resolução pode estar mais próxima de nós do que imaginamos
Influence of Bound Ion on the Morphology and Conductivity of Anion-Conducting Block Copolymers
International audienceAnion-conducting membranes are important for several applications including fuel cells and artificial photosynthesis. In this study such membranes were made by quaternizing polystyrene-block-polychloromethylstyrene (PS-b-PCMS) copolymers. PS-b-PCMS copolymers with molecular weights ranging from 4 to 60 kg/mol were synthesized by nitroxide-mediated controlled radical polymerization. Separate aliquots of the PS-b-PCMS samples were quaternized to transform the PCMS block. This resulted in block copolymers with ionizable blocks containing either trimethylammonium chloride or n-butylimidazolium chloride. We refer to ion-containing block copolymers synthesized from the same precursor as matched pairs: SAM (containing trimethylammonium chloride) and SIM (containing n-butylimidazolium chloride). The volume fraction of the ion-containing block, ϕ, ranges from 0.26 to 0.50 for the case of SAM and from 0.35 to 0.60 for the case of SIM. Self-assembly in these copolymers resulted in the formation of lamellar phases regardless of ϕ, chemical formula of the bound ion, and chain length. Chloride ion conductivity and water uptake measurements on one of the matched pairs led to similar results. Preliminary experiments wherein the chloride ions in this matched pair were replaced by hydroxide ions were performed, and the changes in conductivity due to this are reported
Avaliação da rede de atenção ao portador de hipertensão arterial: estudo de uma região de saúde
Triphenylphosphine-Containing Thermo-Responsive Copolymers: Synthesis, Characterization and Catalysis Application
Structural characterization of amphiphilic homopolymer micelles using light scattering, SANS, and Cryo-TEM
We report the aqueous solution self-assembly of a series of poly(N-isopropylacrylamide) (PNIPAM) polymers end-functionalized with a hydrophobic sulfur–carbon–sulfur (SCS) pincer ligand. Although the hydrophobic ligand accounted for <5 wt % of the overall homopolymer mass, the polymers self-assembled into well-defined spherical micelles in aqueous solution, and these micelles are potential precursors to solution-assembled nanoreactors for small molecule catalysis applications. The micelle structural details were investigated using light scattering, cryogenic transmission electron microscopy (cryo-TEM), and small angle neutron scattering (SANS). Radial density profiles extracted from the cryo-TEM micrographs suggested that the PNIPAM chains formed a diffuse corona with a radially decreasing corona density profile and provided valuable a priori information about the micelle structure for SANS data modeling. SANS analysis indicated a similar profile in which the corona surrounded a small hydrophobic core containing the pincer ligand. The similarity between the SANS and cryo-TEM results demonstrated that detailed information about the micelle density profile can be obtained directly from cryo-TEM and highlighted the complementary use of scattering and cryo-TEM in the structural characterization of solution assemblies, such as the SCS pincer-functionalized homopolymers described here
Hollow block copolymer nanoparticles through a spontaneous one-step structural reorganization
The spontaneous one-step synthesis of hollow nanocages and nanotubes from spherical and cylindrical micelles based on poly(acrylic acid)-b-polylactide (P(AA)-b-P(LA)) block copolymers (BCPs) has been achieved. This structural reorganization, which occurs simply upon drying of the samples, was elucidated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). We show that it was necessary to use stain-free imaging to examine these nanoscale assemblies, as the hollow nature of the particles was obscured by application of a heavy metal stain. Additionally, the internal topology of the P(AA)-b-P(LA) particles could be tuned by manipulating the drying conditions to give solid or compartmentalized structures. Upon resuspension, these reorganized nanoparticles retain their hollow structure and display significantly enhanced loading of a hydrophobic dye compared to the original solid cylinders