Louisiana State University
Dr. Qinglin Wu is currently Roy O. Martin Sr. Professor in Composites and Engineered Wood Products at the Louisiana State University. He received a Ph.D. in Wood Science and Engineering (Minor: Mechanical Engineering) from Oregon State University in 1993. His research emphases include wood/natural fiber polymer composites, biomaterials from natural polymers, composite durability and engineering performance, and nano-composite materials. Dr. Wu has received numerous honors and awards including 2009 LSU AgCenter Rogers Excellence in Research Award, 2008 Sigma Delta Gamma Honor Society Research Award, Fellow for International Academy of Wood Science, Markwardt Wood Engineering Award for Excellence in Wood Engineering Research and Wood Award for Excellence in Graduate Research, and Visiting Professorship from Several Universities in China. He has served on various committees and panels for professional societies and government agencies. Dr. Wu’s research is published in over 100 technical papers in journals, books, and proceedings. His research has been supported by the National Science Foundation (NSF), Louisiana Board of Regents, USDA National Research Initiative Competitive Grants Program (NRICGP), USDA/DOE Biomass Research Program, and wood-products industry. Dr. Wu teaches both undergraduate and graduate courses in the School of Renewable Natural Resources. These courses include Wood Science and Forest Products, Wood Composite Manufacturing, and Wood/Wood Composite Mechanics.
Rheological and filtration characteristics of drilling fluids are considered as two critical aspects to ensure the success of a drilling operation. This research demonstrates the effectiveness of cellulose nanoparticles (CNPs), including microfibrillated cellulose (MFC) and cellulose nanocrystals (CNCs) in enhancing the rheological and filtration performances of bentonite (BT) water-based drilling fluids (WDFs). CNCs were isolated from MFC through sulfuric acid hydrolysis. In comparison with MFC, the resultant CNCs had much smaller dimensions, more negative surface charge, higher stability in aqueous solutions, lower viscosity, and less evident shear thinning behavior. These differences resulted in the distinctive microstructures between MFC/BT and CNC/BT-WDFs. A typical “core-shell” structure was created in CNC/BT-WDFs due to the strong surface interactions among BT layers, CNCs and immobilized water molecules. However, a similar structure wasn’t formed in MFC/BT-WDFs. As a result, CNC/BT-WDFs had superior rheological properties, higher temperature stability, less fluid loss volume, and thinner filter cakes than BT and MFC/BT-WDFs. Moreover, the presence of polyanionic cellulose (PAC) further improved the rheological and filtration performances of CNC/BT-WDFs, suggesting a synergistic effect between PAC and CNCs.