Effect of aromatic amines on the properties of formaldehyde-based xerogels

This study investigates the synthesis of formaldehyde-based xerogels using alternative aromatic precursors, with comparison to traditional resorcinol-formaldehyde analogues, in order to alter the chemical composition of the resulting gels. By replacing resorcinol with aromatic amine molecules, i.e., ammeline, melamine and melem, each expected to undergo similar reactions with formaldehyde as the substituted species, we found that for all substituted gels, at low additive contents, the gel structure was compromised and non-porous materials were formed, as opposed to the most abundant monomers, and therefore, these additives seem to act as impurities at low levels. Working towards higher additive contents, melem monomers exhibited low solubility (~5%), even at elevated temperatures, thereby limiting the range to which melem could act as a substitute, while melamine could be incorporated up to ~40% under acidic conditions, with enhanced microporosity over this range. Pure gels were successfully synthesised from ammeline, but their performance was inferior to resorcinol-formaldehyde gels, while melamine-formaldehyde analogues required acidic reaction conditions but shrank considerably on sub-critical drying, adversely affecting the gel properties and demonstrating their lack of potential as sorbents. This demonstrates the potential for the inclusion of aminated aromatics within resorcinol-based gel systems, however, only as partial substitutes and not complete replacements

Modelling organic gel growth in three-dimensions : textural and fractal properties of resorcinol-formaldehyde gels

Tailoring the properties of porous organic materials, such as resorcinol–formaldehyde gels, for use in various applications has been a central focus for many studies in recent years. In order to achieve effective optimisation for each application, this work aims to assess the impact of the various synthesis parameters on the final textural properties of the gel. Here, the formation of porous organic gels is modelled using a three-dimensional lattice-based Monte Carlo simulation. We model growth from monomer species into the interconnected primary clusters of a gel, and account for varying catalyst concentration and solids content, two parameters proven to control gel properties in experimental work. In addition to analysing the textural properties of the simulated materials, we also explore their fractal properties through correlation dimension and Hurst exponent calculations. The correlation dimension shows that while fractal properties are not typically observed in scattering experiments, they are possible to achieve with sufficiently low solids content and catalyst concentration. Furthermore, fractal properties are also apparent from the analysis of the diffusion path of guest species through the gel’s porous network. This model, therefore, provides insight into how porous organic gels can be manufactured with their textural and fractal properties computationally tailored according to the intended application

Valorar lo Nuestro Para Fortalecer el Futuro: Etnoturismo Mapuche en la IX Región

The mapuche people have lived a history of struggle. Today it seems they are faced with the impossible choice of being poor and without the resources to maintain their culture, or succumbing to the pressures of a world imbued with globalization and equally changing what is fundamentally theirs. As a unique solution to this problem, many mapuche individuals and communities have opted to develop “turismo mapuche”, or ethnic tourism programs—part of a recent trend toward a more responsible form of tourism. These programs strive to provide tourists with the opportunity to experience cultures different from their own. The primary aim of this study was to determine if these programs provide the mapuche with a viable way to maintain and strengthen their culture. In order to investigate this I lived in two different communities where ethic tourism has become an integral part of life. I incorporated myself into these communities through observing, interviewing, and actively participating in the daily activities and elements of the tourism programs. I also conducted interviews at governmental organizations and tourism agencies that play a role in supporting the mapuche in their efforts. The results of my investigation include a detailed description of each of the two ethic tourism initiatives and an analysis of their internal strengths and weaknesses, as well as external opportunities and threats. In both cases I saw that ethic tourism does indeed provide the mapuche with both a greater economic income and the possibility to strengthen their culture. The mapuche people have a deep respect for nature and the environment, and this importance is manifested in the programs as well. Finally, the benefits of these programs extend to the tourists themselves, often having a deep impact on their outlook on life and their view of the mapuche people

LGBTQ+ Children’s Picture Books in Ontario Public Libraries

Diverse representation in picture books is important for the wellbeing of children and families; this includes LGBTQ+ representation, a frequently contested area of literature. Our poster identifies 33 of the most frequently recommended picture books with LGBTQ+ representations and reports on their inclusion in 40 selected Ontario Public Libraries. We then compared these results with five socioeconomic factors for each library: size of population served, the size of the print collection, the size of the materials budget, the average total median household income and the last decade of provincial election results for the riding in which the main branch of the library is located. Visit this poster to see which books were the most frequently recommended and the trends impacting your local library

Investigating the role of the catalyst within resorcinol-formaldehyde gel synthesis

Resorcinol–formaldehyde (RF) gels are porous materials synthesized via a sol–gel reaction and subsequently dried, producing structures with high surface areas and low densities—properties that are highly attractive for use in various applications. The RF gel reaction takes place in the presence of a catalyst, either acidic or basic in nature, the concentration of which significantly impacts final gel properties. The full extent of the catalyst’s role, however, has been subject to debate, with the general consensus within the field being that it is simply a pH-adjuster. The work presented here explores this theory, in addition to other theories postulated in the literature, through the synthesis and analysis of RF gels catalysed by mixtures of relevant compounds with varying concentrations. The relationship between catalyst concentration and initial solution pH is decoupled, and the individual roles of both the cation and the anion within the catalyst are investigated. The results presented here point towards the significance of the metal cation within the RF gel reaction, with similar structural properties observed for gels synthesized at constant Na+ concentrations, regardless of the initial solution pH. Furthermore, through the use of alternative cations and anions within catalyst compounds, the potential effects of ions on the stabilization of macromolecules in solution are explored, the results of which suggest a ‘Hofmeister-like’ series could be applicable within the catalysis of RF gel reactions

Building and Maintaining LGBTQ+ Picture Book Collections

The LGBTQ+ community has had to continuously fight for their rights, including their right to be represented in the library. This toolkit provides instruction on how to develop and manage a library collection of LGBTQ+ children’s picture books. It is split into four sections that include a guide to evaluating materials, recommended picture books, a guide to fighting censorship, and a list of recommended resources

Examining the Development of a Social Media Strategy for a National Sport Organisation A Case Study of Tennis New Zealand

The application of technology and the rise in social media has not gone unnoticed in sports and has become a vital tool for sport marketers as sport consumers’ media consumption grows. This paper offers an analysis on the development and maintenance of a social media strategy for a National Sport Organisation (NSO) in New Zealand. This initiative, implemented for Tennis New Zealand (TNZ) in 2010, was conducted to provide a minority sport (in terms of mainstream media) with its first online social media presence. This study involved a qualitative and quantitative analysis of Tennis New Zealand’s (TNZ) development and maintenance of a social media strategy through fieldwork, social media metrics data collection and analysis, and evaluation, and highlights a number of issues in the development and effective utilisation of social media for an NSO. In particular applying a ‘one size fits all’ approach to its management despite the uniqueness of the sport product. Creative online strategies using technologies such as Facebook must be employed, monitored and evaluated to ensure they continue to meet the needs and expectations of all stakeholders. Such strategies include the use of promotions, ‘behind-the-scenes’ material, and constant engagement and conversation with fans and followers

Modelling the formation of porous organic gels-how structural properties depend on growth conditions

There has been significant research interest invested into the study of the formation and properties of porous organic materials, due to their widespread applications. However, present models in the literature do not fully explain the observations made for these systems, therefore, this work presents a model developed to fully capture growth from the monomeric species present in the initial stages of the gelation composition. In this work, we employ a two-dimensional lattice-based kinetic Monte Carlo model to investigate how growth processes impact the structural properties of model gels. Experimentally, gel growth is primarily controlled through catalyst concentration, which determines the density of species that are activated for rapid growth, and solids concentration; our model captures both of these dependencies. Increasing both solids content and percentage of activated monomers leads to a higher ratio of closed porosity, and higher values of accessible surface area with increasing level of activation. The generated structures are analysed for their fractal properties using a correlation dimension. Increasing both solids content and percentage of activated species leads to an increase in correlation dimension, which plateaus at a value of 2, independent of catalyst concentration, suggesting little structural change at high solid loadings, over 50%. The Hurst exponent of a random walker diffusing in the accessible pores shows the opposite trend, varying from 1/2 for unconstrained diffusion and reducing to 1/3; for diffusion through the pore network at the threshold of percolation. These characteristics support visual observations of increasing complexity and tortuosity of pore structures in the model cluster structures. The implications of these results, for the design of porous structures tailored to particular applications, are discussed

Effect of s-triazine ring substitution on the synthesis of organic resorcinol-formaldehyde xerogels

Resorcinol (R) and formaldehyde (F) gel synthesis has been well-studied along with alternative reagents. We present the synthesis of formaldehyde-based xerogels using chemically similar s-triazine precursors, with comparison to traditional analogues. The substitution ranges from tri-hydroxyl to tri-amine, with an intermediate species, allowing changing chemistry to be investigated. Each molecule (X) offers different acid/base properties, known to influence gel formation, as well as differences in crosslinking potential. Varying X/F ratios were selected to recreate the stoichiometry used in RF systems, where one represented higher F to match the increased reaction sites of the additives. X/C ratios were selected to probe different catalyst (C) ratios, while working within the range likely to produce viable gels. Results obtained show little impact for ammeline as an additive due to its similarity to resorcinol (activation sites and pKa); while melamine and cyanuric acid show differing behavior depending on the level of addition. Low concentrations show melamine to have the most impact due to increased activation and competition for formaldehyde; while at high concentrations, cyanuric acid is shown to have the greatest impact as it creates a more acidic environment, which diminishes textural character, possibly attributable to larger clusters and/or weaker cross-linking of the system

The impact of deuterium oxide on the properties of resorcinol-formaldehyde gels

Resorcinol-formaldehyde gels offer a range of properties that can be exploited in a variety of applications, but better understanding of gel formation mechanisms is needed to enable rational control and optimisation of the physico-chemical characteristics of these materials. Our previous studies have focussed on investigating the formation pathways of these gels, using nuclear magnetic resonance and dynamic light-scattering techniques, as well as evaluating their final physical and chemical properties, via sorption and spectroscopic methods. Nuclear magnetic resonance has been used over the years to probe the chemical species formed during resorcinol-formaldehyde gel polymerisation, but the technique typically involves the prior addition of deuterium oxide to provide a deuterium lock for NMR measurements. However, the effect of deuterium oxide to resorcinol-formaldehyde systems is currently unknown, although the substitution of water by deuterium oxide has been previously reported to alter the chemical and physical properties of reacting systems. In this work we examine the effect of adding deuterium oxide to resorcinol-formaldehyde sol-gel synthesis at different dilution levels and the impact that this addition has on the final characteristics of the synthesised gels, in order to assess the validity of using NMR with a deuterium lock for the investigation of polymerisation mechanism in resorcinol-formaldehyde sol-gel processes