Materials from renewable resources: new properties and functions

Sustainable production requires increasing use of raw materials from renewable sources, processed under mild conditions with minimal effluent production. These requirements are satisfied by using materials derived from biomass, in synergy with food and energy production. The possibilities of biomass are continuously enlarged by new findings, as in the intrinsic nanocomposite properties of natural rubber and the amphiphile behavior of cellulose that translated into new functional materials, including high-performance, flexible and conductive non-metallic materials. Other findings are allowing a better understanding of electrostatic phenomena that play a positive role in electrostatic adhesion and cohesion of nanocomposites made from biomass products. Moreover, this should allow the development of safe electrostatic separation techniques, suitable for the fractionation of crude mixtures of biomass residues. A current study on rubber electrostatics is showing its capabilities as a transducer of mechanical energy while providing clues to understand the performance of the dielectric elastomers used in robotic self-sensing actuators914CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP465452/2014-088887.284776/2018-002014/50906-

Application of computational quantum chemistry to chemical processes involved in mass spectrometry

The field of application of mass spectrometry (MS) has increased considerably due to the development of ionization techniques. Other factors that have stimulated the use of MS are the tandem mass spectrometry (MS/MS) and sequential mass spectrometry (MSn) techniques. However, the interpretation of the MS/MS and MSn data may lead to speculative conclusions. Thus, various quantum chemical methods have been applied for obtaining high quality thermochemical data in gas phase. In this review, we show some applications of computational quantum chemistry to understand the formation and fragmentation of gaseous ions of organic compounds in a MS analysis.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPESPCNP

Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM). Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the particles, while S is uniformly distributed within then. The Na and N elemental maps show that the respective monovalent ions (Na+ and NH4+) have different distributions, in the latex: Na signal within the particles is stronger than in the background, while N is accumulated at the particle borders. The distributions of surfactant and counter-ions are thus different from some current assumptions, but they support recent results on the distribution of ionic constituents in latex films, by scanning electric potential microscopy.Submonocamadas de látex estireno-acrílico preparado usando um tensoativo sulfonato reativo e um tensoativo fosfato não-reativo foram examinadas em um microscópio de transmissão equipado com um espectrômetro de perda de energia de elétrons, para a aquisição de mapas de distribuição elementar. P está ausente do centro das partículas mas é encontrado em uma casca espessa, no fundo da imagem e em estruturas incomuns com um baixo teor de carbono, enquanto S está uniformemente distribuído nas partículas. Os mapas elementares de Na e N mostram que os respectivos cátions (Na+, NH4+) têm diferentes distribuições: o sinal de Na é mais intenso nas partículas do que no fundo, enquanto N se acumula nas bordas das partículas. As distribuições de tensoativos e contra-íons são portanto diferentes de algumas suposições correntes, mas elas estão de acordo com resultados recentes sobre a distribuição de constituintes iônicos em látex, obtidas por microscopia de varredura de potencial elétrico.6674Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

A Fragmentation study of di-acidic mycosporine-like amino acids in electrospray and nanospray mass spectrometry

Two mycosporine (MAAs), containing an extra acid function, were analyzed by nanospray and electrospray ionization tandem mass spectrometry. In contrast to the previous studies it is demonstrated that no significant characteristic methyl radical loss occurred in positive mode. The fragmentation pathway in negative mode was also proposed in this work, along with theoretical calculations to characterize the site of protonation.No presente estudo, duas micosporinas (MAAs) contendo um segundo ácido carboxílico foram submetidas à fragmentação em eletrospray e nanospray em diferentes equipamentos. Em contraste com resultados anteriores, a eliminação de radical metila no modo positivo de análise foi um processo minoritário de fragmentação. Neste trabalho apresentamos também a via de fragmentação destas substâncias em modo negativo e cálculos teóricos para caracterizar os sítios de protonação.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Chemistry post 2022 movement : formulation of an action plan so that chemistry and its actors impact the sustainability and sovereignty in Brazil

Considering the bicentenary of Brazil’s Independence in 2022 and that this year was proclaimed by UNESCO as the International Year of Basic Sciences for Sustainable Development, in mid-2021 the Brazilian Chemical Society (SBQ) launched the "Post 2022 Chemistry Movement – Sustainability and Sovereignty", with the main goal of promoting different activities so that chemistry contributes for the sustainable development and sovereignty of Brazil in the coming years. One of these activities is the proposal of an action plan, with goals to be achieved by 2030 and 2050. This article describes in detail how this action plan was formulated by a working group, with the help of an advisory council and interviews of 18 professionals from universities, the government, industries, the third sector and other organizations. Mimicking the Agenda 2030 SDGs, the resulting action plan is based on two broad Chemistry Sustainable Development Goals: promoting sustainability through chemistry in basic education, and promoting sustainability in the industry and university through science, technology, innovation, and education (STI&E) in chemistry. After the definition of three driving technological challenges in STI&E, they shall be successively implemented through different actions starting in 2023 yet

Photoinduced formation of gold nanoparticles into vinyl alcohol based polymers

Nanocomposites based on vinyl alcohol-containing polymers and nanostructured gold have been efficiently prepared by a UV photo-reduction process. The very fast process provided dispersed gold nanoparticles with average diameters ranging from 3 to 20 nm depending on the host polymer matrix and the irradiation time. Uniaxial drawing of the irradiated Au/polymer nanocomposites favours the anisotropic distribution of packed assemblies of gold particles, providing oriented films with polarization-dependent tunable optical properties. These pronounced dichroic properties suggest that the nanocomposite films could find potential applications as colour polarizing filters, radiation responsive polymeric objects and smart flexible films in packaging applications.16111058106

Fragmentation study of di-acidic mycosporine-like amino acids in electrospray and nanospray mass spectrometry

No presente estudo, duas micosporinas (MAAs) contendo um segundo ácido carboxílico foram submetidas à fragmentação em eletrospray e nanospray em diferentes equipamentos. Em contraste com resultados anteriores, a eliminação de radical metila no modo positivo de análise foi um processo minoritário de fragmentação. Neste trabalho apresentamos também a via de fragmentação destas substâncias em modo negativo e cálculos teóricos para caracterizar os sítios de protonação. Two mycosporine (MAAs), containing an extra acid function, were analyzed by nanospray and electrospray ionization tandem mass spectrometry. In contrast to the previous studies it is demonstrated that no significant characteristic methyl radical loss occurred in positive mode. The fragmentation pathway in negative mode was also proposed in this work, along with theoretical calculations to characterize the site of protonation. Keywords: mycosporine, nanoESI-MS/MS, ESI-MS/MS, natural products, algae Introduction Mycosporine-like amino acids (MAAs) are a group of chemically related, water soluble compounds responsible for UV photoprotection in a diverse range of organisms including invertebrates, fish, bacteria, cyanobacteria, micro-and macroalgae. 1-3 These compounds are chemically characterised by the presence of either a cyclohexenone or cyclohexenimine chromophore conjugated with a substituent nitrogen of an amino acid, amino alcohol or amino group 1 MAAs normally show a strong UV absorption between 310 and 360 nm with high molar extinction coefficients. These characteristics indicate a possible photoprotective role that has been demonstrated in a number of studies 11-13 17 In the last few years, nanospray ionisation (nanoESI) is beginning to increase in importance, especially with the development of automated systems using 'chips' (arrays of uniform nanospray needles that are used only once to avoid contamination). 21 NanoESI offers the possibility of improved sensitivity and lower sample consumption over conventional ESI for the analysis of natural products. 22 This is especially important for the study of extracts from biological and medicinal sources when often only a very small amount of material is available. In 'chip based' nanoESI, the analyte solution is sprayed from a conducting pipette tip pressed against the rear of a chip using a small gas pressure and much lower voltages to create the spray. Recently, analysis of some natural antioxidants (retinoids Experimental Chemicals All solvents used were HPLC grade (Tedia, J. Baker and Fisher). Water was purified using a Milli-Q system (Millipore, Bedford, MA, USA). Trifluoroacetic acid (99.9%) was purchased from Aldrich. Galena Química e Farmacêutica Ltda/Brazil kindly supplied the standards of shinorine and porphyra-334 (product Helioguard ® 365-Porphyra umbilicalis extracts) Instrumentation Nanospray ionisation analyses were performed on two quadrupole-time of flight hybrid instruments: (a) an UltrOTOF-Q (Bruker Daltonics, Billerica, MA) using Tip™ Emittek (glass tip capillaries working with 500 V) or (b) a QStar-XL (Applied Biosystems, Warrington, UK) using a Nanomate HD automatic 'chip based' nanospray system (Advion Biosciences, Norwich, UK). The Nanomate was set for 5 µL of solution to be aspirated and sprayed through a Nanomate 400 chip at 1.45 kV, with a nitrogen back pressure of 0.4 psi. On both instruments, the ion source gas and curtain gas were nitrogen. Electrospray ionisation analyses were performed on five instruments: (a) an Apex 4 7.0 Tesla Fouriertransform ion-cyclotron resonance mass spectrometer (Bruker Daltonics, Billerica, MA, USA). Samples were directly infused into the Apollo electrospray source from a syringe pump at 100 µL h -1 . Analyses were performed at a capillary voltage, of 4600V and capillary exit potential of 200 V (except were indicated otherwise). The N 2 drying gas temperature was 200 °C. A mixture of PEG grades was used as an external calibrant for accurate-mass ESI analysis; (b) on a quadrupole-time of flight instrument (UltrOTOF-Q, Bruker Daltonics, Billerica, MA). The analyses were performed in positive ion ESI mode at a capillary voltage of 3400 V and N 2 drying gas temperature of 180 °C. NaTFA 10 mmol L -1 was used as a standard for internal and external calibration; (c) on a QStar-XL quadrupole-time-of-flight instrument (Applied Biosystems, Warrington, UK); (d) on a Quattro-LC triple quadrupole mass spectrometer (Micromass, Manchester, UK); (e) on an Esquire HCT ion trap instrument (Bruker Daltonics, Billerica, MA, USA) using a syringe pump (Cole-Parmer, Vernon Hills, IL, USA). Ion trap analyses were performed using nitrogen as the nebulising and drying gas and helium as the bath gas (4×10 -6 mbar). Theoretical calculations All calculations were performed in Gaussian 03 27 suite of programs using the B3LYP/6-31+G(d,p) model. 28,29 The geometries of neutral and protonated species were optimised and the potential energy surface minima were indicated by analysis of vibrational frequencies. The gasphase basicity and proton affinity were calculated via a protonation reaction, using Gibbs energies and enthalpies, respectively. 30 Cardozo et al. 1627 Vol. 20, No. 9, 2009 Results and Discussion Mycosporine-like amino acids with one acidic function were previously analysed by positive mode ESI sequential mass spectrometry (at high-resolution and accurate-mass). The loss of a methyl radical by the homolytic cleavage of the O-C bond was observed to be the preferred fragmentation pathway. As expected, analysis in negative ion mode Conclusions These results indicate that the presence of a second carboxylic acid function significantly reduces the intensity of the observed product ions from the radical methyl cleavage in positive mode MS/MS. As expected, in the negative ion mode, the radical fragmentation pathway does not occur. Taken together, these results confirm the importance of careful selection of the product ions used for analytical protocols for the analysis of crude extracts containing MAAs where the presence of the second acid function may change the fragmentation behavior and the classical analysis of loss of methyl radical may lead to the wrong conclusions during screening for MAAs

Space Charge at Nanoscale: Probing Injection and Dynamic Phenomena Under Dark/Light Configurations by Using KPFM and C-AFM

International audienc