The School of Forestry and Wildlife Sciences’ Weaver Lecture Series was established in May of 1996 through an endowment provided by Earl H. and Sandra H. Weaver. The objective of the Series is to bring individuals with expertise in various aspects of forestry and wildlife sciences to the Auburn University campus to enhance the School’s academic programs through public lectures and interaction with faculty and students.
Orlando J. Rojas, Professor
Aalto University, Finland
“Nanocelluloses and Multi-phase Systems”
Thursday, March 30, 2017
Forestry and Wildlife Sciences Building, Room 1101
Please join us prior to the lecture for a reception at 3:30 p.m.
Dr. Rojas is a Professor of Biobased Colloids and Materials at Aalto University, Finland. Previously, he was Professor in the departments of Chemical and Biomolecular Engineering and Forest Biomaterials of North Carolina State University (USA). Earlier in his career he was a senior scientist appointed by the Royal Swedish Academy of Sciences in the Royal Institute of Technology (KTH), a postdoctoral fellow in the Institute for Surface Chemistry, Sweden and research assistant in Auburn University. He was appointed as Finland Distinguish Professor (2009-2014) and was Chair of the “Division of Cellulose and Renewable Materials” of the American Chemical Society (2009-2011). He was elected with the distinction of Fellow of the American Chemical Society (2013) for his scientific and professional contributions. He is the recipient of the 2015 Nanotechnology Division Technical Award and IMERYS Prize for outstanding contributions that have advanced the industry’s technology. He was appointed as a “2013-2017 Faculty Scholar” of NCSU and ACS Division Award of “Cellulose and Renewable Materials”. He received the Fibrenamics Award (University of Minho, Portugal, 2016) in recognition for his scientific work and impact in the field of advanced materials from lignocellulose. Recently he was selected as front-runner for the Academy Professor of Finland. Dr. Rojas work is centered on the utilization of lignocellulosic materials in novel, high performance applications and the interfacial and the adsorption behaviors of surfactants and biopolymers at solid/liquid interfaces. He has published over 220 peer-reviewed papers related to these topics. He and his students have given +300 conference presentations and has been invited numerous times (+190) as a speaker in conferences, universities and research centers worldwide. The recent efforts of his group, “Bio-based Colloids and Materials”, deal with the development of nano-structures from the fiber cell wall and cellulose derivatives, the dynamics of enzymatic reactions and the design of stimuli-responsive materials and multi-phase systems.
“Nanocelluloses and Multi-phase Systems” Abstract:
We introduce our work related to the application of surface and colloid science in the development of lignocellulose nanomaterials. These efforts take advantage of the process by which nature assembles fibers in a highly hierarchical structure encompassing a wide range of sizes, from the nano to the meter scales. A number of materials cleaved from the cell wall have been the subject of intensive research, including, nanofibrillar cellulose and cellulose nanocrystals (CNCs), i.e., defect-free, rod-like crystalline residues after acid hydrolysis of cellulose fibers. Interest in nanocellulose originates from its appealing intrinsic properties: nanoscale dimensions, high surface area, unique morphology, low density, chirality and mechanical strength. Directing their assembly back to different hierarchical 1D, 2D and 3D structures is a quest that can yield useful results in many revolutionary applications. As such, we will discuss the use of non-specific forces to create ultrathin films of nanocellulose at the air-solid interface for applications in nanocoatings, sensors, etc. Assemblies at other interfaces will be introduced as means to produce or stabilize hydrogels, aerogels, and Pickering emulsions. Methods common in biophysics and employed to control the packing density of CNC at the air-liquid and air-solid interfaces will be presented. A convective assembly setup assisted by shear and electric fields will be discussed as a suitable method to produce highly ordered structures. Concepts related to piezoelectric CNC films, organic-inorganic hybrid materials with magnetic and other properties. Overall, the prospects of such novel materials will be explained in light of the unique properties of cellulose.
David Fowler, Professor
Centre for Ecology and Hydrology, Edinburgh, UK
“Impacts of Human Activities on the Global Nitrogen Cycle Through the 21st century”
Tuesday, April 11, 2017
Forestry and Wildlife Sciences Building, Room 1101
Please join us prior to the lecture for a reception at 3:00 p.m.
Professor Fowler is an environmental physicist with the Centre for Ecology and Hydrology (CEH) and is based in Edinburgh. He trained in Environmental Physics at the University of Nottingham, obtaining a PhD in 1976 from research on the dry deposition of SO2 by micrometeorological methods. He has worked at the Institute of Terrestrial Ecology (now known as CEH) since 1975 on a range of atmospheric trace gases including SO2, NO2, NO, HNO3, NH3, O3, CH4, N2O as well as aerosols and cloud droplets. His research focuses on the surface – atmosphere exchange processes of trace gases and particulate matter and has been applied to ozone, acid deposition, the global biogeochemical cycle of nitrogen, emissions of greenhouse gases, atmospheric aerosols and effects of pollutants on vegetation. He also has a particular interest in the policy applications of air quality research and has been closely involved with policy teams in the UK, the EU and UNECE. Dr. Fowler has been a contributing author to more than 230 refereed publications in addition to contributions to book chapters and conference proceedings, and has an H index of 56. He was awarded an Honorary Professorship at the University of Nottingham in 1991, became a Fellow of the Royal Society of Edinburgh in 1999, and a Fellow of the Royal Society of London in 2002. In 2005 he was awarded a CBE for services to research into Atmospheric Pollution.
“Impacts of Human Activities on the Global Nitrogen Cycle Through the 21st Century” Abstract:
Ecosystems both natural and those managed by human activities depend on nitrogen, a key constituent of proteins. Yet few organisms are able to process molecular nitrogen in the atmosphere, it is simply chemically unavailable to them. Ecosystems have evolved to work with the reactive nitrogen (Nr) provided by microorganism nitrogen fixers. The nitrogen fixed from the atmosphere is processed by food webs and returned to the atmosphere again by microorganisms, creating a natural nitrogen cycle. Until the early 20th century farmers and industry used the nitrogen fixed by microbes. The First World War created a huge demand for fixed nitrogen, a vital component of explosives, which was satisfied by industrial nitrogen fixation (Haber-Bosch). Since then, industrial demand and agriculture have driven demand for fixed nitrogen for food production and industry. In addition, atmospheric nitrogen is also fixed by combustion of any fuel. Thus nitrogen fixation has steadily increased through the last century, and the amount fixed by human activity has doubled the amount of fixed nitrogen globally cycling through ecosystems, the atmosphere and oceans.
Should we be concerned? The reactive nitrogen in the atmosphere is responsible for the increase in ground level ozone, and associated human health and crop loss issues throughout the developed world. Reactive nitrogen deposited on natural ecosystems in Europe and North America is reducing the species richness of our flora. Nitrogen compounds are responsible for 20-40% of the inorganic particulate matter in the atmosphere, and associated human health and climate impacts. Nitrous oxide, the third most important climate gas is increasing due to human perturbation of the nitrogen cycle. There is no global strategy to regulate the use of Nr and projected changes in demand and climate change will increase anthropogenic nitrogen fixation so that by the end of the century the global nitrogen cycle will be dominated by human activity. There is clearly a problem.