Browsing by Author "Rodriguez, Katia"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Environmental science and engineering applications of nanocellulose-based nanocomposites
    Wei, Haoran; Rodriguez, Katia; Renneckar, Scott; Vikesland, Peter J. (The Royal Society of Chemistry, 2014-06-26)
    Compared with cellulose, the primary component of the paper we use every day, nanocellulose has a much smaller diameter (typically <10 nm) that renders it many unique properties. Amongst many others, these properties include high mechanical strength, large surface area and low visual light scattering. Nanocellulose can be obtained by disintegration of plant cellulose pulp or by the action of specific types of bacteria. Once produced, nanocellulose can be used to make transparent films, fibers, hydrogels, or aerogels that exhibit extraordinary mechanical, thermal, and optical properties. Each of these substrates is a suitable template or carrier for inorganic nanoparticles (NPs), thus enabling production of nanocomposites that possess properties of the two constituents. In this review, we focus on the preparation of nanocellulose, nanocellulose films, and nanocellulose papers, and introduce nanocellulose-based nanocomposites and their environmental applications.
  • Thumbnail Image
    Preparation and evaluation of nanocellulose-gold nanoparticle nanocomposites for SERS applications
    Wei, Haoran; Rodriguez, Katia; Renneckar, Scott; Leng, Weinan; Vikesland, Peter J. (The Royal Society of Chemistry, 2015-06-09)
    Nanocellulose is of research interest due to its extraordinary optical, thermal, and mechanical properties. The incorporation of guest nanoparticles into nanocellulose substrates enables production of novel nanocomposites with a broad range of applications. In this study, gold nanoparticle/bacterial cellulose (AuNP/BC) nanocomposites were prepared and evaluated for their applicability as surface-enhanced Raman scattering (SERS) substrates. The nanocomposites were prepared by citrate mediated in situ reduction of Au3+ in the presence of a BC hydrogel at 303 K. Both the size and morphology of the AuNPs were functions of the HAuCl4 and citrate concentrations. At high HAuCl4 concentrations, Au nanoplates form within the nanocomposites and are responsible for high SERS enhancements. At lower HAuCl4 concentrations, uniform nanospheres form and the SERS enhancement is dependent on the nanosphere size. The time-resolved increase in the SERS signal was probed as a function of drying time with SERS ‘hot-spots’ primarily forming in the final minutes of nanocomposite drying. The application of the AuNP/BC nanocomposites for detection of the SERS active dyes MGITC and R6G as well as the environmental contaminant atrazine is illustrated as is its use under low and high pH conditions. The results indicate the broad applicability of this nanocomposite for analyte detection.