Sustainable Built Environments Senior Capstone Project / A large portion of current architectural design practices utilize insulative materials that are outdated, unsustainable, and harmful to the environment. There is little consideration placed in the lifespan of the insulative materials and often lead towards negative ramifications the environment must face. Continuing in the track of sustainable development, an emerging material known as cellulose aerogel builds off precedent aerogel with a green twist. The issue with implementing a new material, especially one that lacks the research and development of presently used materials, is gathering enough interest to build research funding. Developing a new material that has the potential to mitigate the massive energy consumption could aid architects and designers in designing more sustainable buildings. A cellulose based aerogel system is fabricated with cellulose, a biomass found in nearly all living organisms, is the answer we may need to make sustainable building practices a reality. To determine the validity of a cellulose aerogel system, a rigorous material study and precedence scientific studies will be analyzed to understand the intrinsic properties. The culmination of this information is imperative to drive continued development and implementation under the optimal conditions. Cellulose aerogel will face a multitude of comparisons with each major used insulative materials such as concrete, wood, and fiberglass. Successfully completing these studies will help material researchers and designers to prepare for a greater sustainable future.

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Detta examensarbete undersöker hur Quartzene® som tillsatsmaterial påverkar hållfastheten hos betong. Arbetet sker i samarbete med företaget Svenska Aerogel AB som också äger patent på Quartzene®. Ämnet har vissa likheter med andra tillsatsmaterial som används i Sverige. Quartzene® har dock ett kartlagt innehåll vilket är en fördel jämfört med de andra tillsatsmaterialen som måste analyseras innan användning. Syftet är att prova hur Quartzene® i olika doser och diverse sammansättningar påverkar hållfastheten hos betong. Litteraturstudier har legat till grund för de praktiska provningarna och analyserna av givna resultat. Arbetet gjordes i ett byggtekniskt laboratorium med utrustning för böjdrag- och tryckhållfasthetstester, våg, elektriskt skjutmått mm. Prover gjordes på 7 och 28 dygn gamla betongprismor. Resultatet som presenteras och analyseras i rapporten visar på att Quartzene® förändrar hållfastheten. Att byta ut en del av cementen mot Quartzene® har ingen positiv inverkan på varken 7 dygn eller 28 dygnshållfastheten. Oklart hur det skulle se ut efter längre tid t ex ett år. Quartzene® blandades i som pasta i vissa betongrecept och som pulver i andra. Konsistensen på betongen blev torrare när Quartzene®pasta blandades i. Trots att pastan innehåller 85 % vatten blev alltså blandningen fast. Den blev dessutom än mer fast efter bara några minuter eftersom pastan stelnar av sig själv. Vattnet i pastan tycktes inte vilja bidra med lägre viskositet. När Quartzene® i pulverform blandades i, blev betongmassan däremot mycket lätt att arbeta med. Det går att dra slutsatser att Quartzene® i pulverform är bättre för hållfastheten än vad Quartzene®pasta är. Den ger ungefär 5 MPa högre tryckhållfasthet. Om 5 MPa skulle adderas till resultaten för betongen som blandades med Quartzene®pasta skulle den ge högre hållfasthet än den som betong var utan Quartzene®. I de recepten med mycket Quartzene® var det en mer positiv utveckling mellan 7 och 28 dygn. Därför hade varit mycket intressant att se hur det skulle ha sett ut efter 90 och 365 dagar.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Florianópolis, 2016. / Made available in DSpace on 2017-06-27T04:15:11Z (GMT). No. of bitstreams: 1 345806.pdf: 7155565 bytes, checksum: 1253d0afab5fd8eeca3a8da2f312b9a9 (MD5) Previous issue date: 2016 / Reatores de energia nuclear geram rejeitos, e estes podem representar uma séria ameaça ao meio ambiente. Rejeitos nucleares líquidos multicomponentes ricos em boro e sódio são solúveis em água e, portanto faz-se necessário desenvolver tecnologias para imobiliza-los. Aerogéis produzidos por secagem supercrítica são notórios por sua alta área superficial e porosidade. Ao secar um gel em condições próximas à ambiente tem-se um ambigel com características similares. Com uma área superficial menor mas com a facilidade de processamento estes ambigéis são adequados para estabilização de rejeitos nucleares líquidos. Ambigéis de sílica foram sintetizados para se investigar quais fatores teriam uma influência sobre o ganho de massa de rejeito. Dois fatores foram avaliados: o tratamento térmico de pré-sinterização e o tempo de imersão no rejeito. Para tal fim foi elaborado um rejeito nuclear multicomponente simulado, rico em H3BO3, NaCl e outros compostos de sódio, com base na composição real das usinas de Angra I e II. Foi demonstrado que nenhum dos dois fatores têm um impacto significativo sobre o ganho de massa, considerando-se os limites testados (100 a 350 °C e 24 a 72 horas).Estes géis foram capazes de absorver uma grande carga de rejeito (>45 %w) e permitiram uma sinterização a temperaturas relativamente baixas (1100 °C) alcançando uma alta densidade. Também foi verificada a presença de uma camada rica em rejeito na superfície exterior dos géis.<br> / Abstract : Nuclear reactors in power plants generate waste, these wastes can pose a serious threat to the environment. Multicomponent liquid nuclear waste rich in boron and sodium are soluble in water and therefore developing technologies for their immobilization becomes even more necessary.Aerogels produced via super-critical drying are notorious for their high surface area and porosity. Drying a wet gel near ambient conditions will create an ambigel instead witch shares similar characteristics With less surface area but easier processing these ambigels are suitable as a trap for liquid nuclear waste.Silica ambigel were produced via sol-gel route to analyze which of two factors would impact on the waste load: pre-sintering heat treatment and/or immersion time in a liquid nuclear waste. For that a simulated multicomponent liquid nuclear waste, rich in H3BO3, NaCl and other sodium compounds was prepared, based on the real composition of Angra I and II reactor waste.We demonstrate that none of the two factors showed significant influence over the tested ranges (100 to 350°C and 24 to 72 hours).It was found that these gels are able to retain a high waste load (>45%w) and allow for relatively low sintering temperature (1100 °C) to turn into a high density wasteform. We have also light on the formation of a highly waste rich layer on the outer surface of the gels.

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<p>Oil spills in marine environments often damage marine and coastal life if not remediated rapidly and efficiently. In spite of the strict enforcement of environmental legislations (i.e., Oil Pollution Act 1990) following the Exxon Valdez oil spill (June 1989; the second biggest oil spill in U.S. history), the Macondo well blowout disaster (April 2010) released 18 times more oil. Strikingly, the response methods used to contain and capture spilled oil after both accidents were nearly identical, note that more than two decades separate Exxon Valdez (1989) and Macondo well (2010) accidents. </p><p>The goal of this dissertation was to investigate new advanced materials (mechanically strong aerogel composite blankets-Cabot® Thermal Wrap™ (TW) and Aspen Aerogels® Spaceloft® (SL)), and their applications for oil capture and recovery to overcome the current material limitations in oil spill response methods. First, uptake of different solvents and oils were studied to answer the following question: do these blanket aerogel composites have competitive oil uptake compared to state-of-the-art oil sorbents (i.e., polyurethane foam-PUF)? In addition to their competitive mechanical strength (766, 380, 92 kPa for Spaceloft, Thermal Wrap, and PUF, respectively), our results showed that aerogel composites have three critical advantages over PUF: rapid (3-5 min.) and high (more than two times of PUF’s uptake) oil uptake, reusability (over 10 cycles), and oil recoverability (up to 60%) via mechanical extraction. Chemical-specific sorption experiments showed that the dominant uptake mechanism of aerogels is adsorption to the internal surface, with some contribution of absorption into the pore space. </p><p>Second, we investigated the potential environmental impacts (energy and chemical burdens) associated with manufacturing, use, and disposal of SL aerogel and PUF to remove the oil (i.e., 1 m3 oil) from a location (i.e., Macondo well). Different use (single and multiple use) and end of life (landfill, incinerator, and waste-to-energy) scenarios were assessed, and our results demonstrated that multiple use, and waste-to-energy choices minimize the energy and material use of SL aerogel. Nevertheless, using SL once and disposing via landfill still offers environmental and cost savings benefits relative to PUF, and so these benefits are preserved irrespective of the oil-spill-response operator choices. </p><p>To inform future aerogel manufacture, we investigated the different laboratory-scale aerogel fabrication technologies (rapid supercritical extraction (RSCE), CO2 supercritical extraction (CSCE), alcohol supercritical extraction (ASCE)). Our results from anticipatory LCA for laboratory-scaled aerogel fabrication demonstrated that RSCE method offers lower cumulative energy and ecotoxicity impacts compared to conventional aerogel fabrication methods (CSCE and ASCE). </p><p>The final objective of this study was to investigate different surface coating techniques to enhance oil recovery by modifying the existing aerogel surface chemistries to develop chemically responsive materials (switchable hydrophobicity in response to a CO2 stimulus). Our results showed that studied surface coating methods (drop casting, dip coating, and physical vapor deposition) were partially successful to modify surface with CO2 switchable chemical (tributylpentanamidine), likely because of the heterogeneous fiber structure of the aerogel blankets. A possible solution to these non-uniform coatings would be to include switchable chemical as a precursor during the gel preparation to chemically attach the switchable chemical to the pores of the aerogel. </p><p>Taken as a whole, the implications of this work are that mechanical deployment and recovery of aerogel composite blankets is a viable oil spill response strategy that can be deployed today. This will ultimately enable better oil uptake without the uptake of water, potential reuse of the collected oil, reduced material and energy burdens compared to competitive sorbents (e.g., PUF), and reduced occupational exposure to oiled sorbents. In addition, sorbent blankets and booms could be deployed in coastal and open-ocean settings, respectively, which was previously impossible.</p> / Dissertation

Amelioration of the building blocks is a plausible approach to graft aerogels with distinguished properties while preserving the aerogel superiority. However, the incorporation of designated properties into metallic aerogels, especially catalytically beneficial morphologies and transition metal doping, still remains a challenge. Here, we report on the first case of an aerogel electrocatalyst composed entirely of alloyed PdNi hollow nanospheres (HNSs) with controllable chemical composition and shell thickness. The synergy of the transition metal doping, combined with the hollow building blocks and the three dimensional network structure make the PdNi HNS aerogels promising electrocatalysts towards ethanol oxidation, among which the Pd83Ni17 HNS aerogel shows a 5.6-fold enhanced mass activity compared to commercial Pd/C. This work expands the exploitation approach of electrocatalytic properties of aerogels into morphology and composition control of its building blocks.