@article{jiang_narron_han_park_chang_jameel_2020, title={Tracing Sweetgum Lignin's Molecular Properties through Biorefinery Processing}, volume={13}, ISSN={["1864-564X"]}, DOI={10.1002/cssc.202001125}, abstractNote={Abstract}, number={17}, journal={CHEMSUSCHEM}, author={Jiang, Xiao and Narron, Robert H. and Han, Qiang and Park, Sunkyu and Chang, Hou-min and Jameel, Hasan}, year={2020}, month={Sep}, pages={4613–4623} }
 @article{ribeiro_vaz junior_jameel_chang_narron_jiang_colodette_2019, title={Chemical Study of Kraft Lignin during Alkaline Delignification of E. urophylla x E. grandis Hybrid in Low and High Residual Effective Alkali}, volume={7}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.8b06635}, abstractNote={Chips from E. urophylla x E. grandis hybrid were subjected to kraft cooking using two different approaches: low and high residual effective alkali. The lignin remaining in the pulps were analyzed for hydroxyl and carboxyl functional groups. For both pulping cases, the kappa number varied between 14 and 26. Significant yield gains were observed when kraft cooking was terminated with low residual effective alkali (L-REA) in contrast to those with high residual effective alkali (H-REA) at a given kappa number. The L-REA pulps also tended to contain higher lignin and lower HexA contents than the H-REA pulps at a given kappa number. Cellulolytic enzyme lignin (CEL) was isolated from the studied pulp’s residual lignins, and their hydroxyl functional group distributions were quantified using a method involving ³¹P NMR. Analysis of residual lignins isolated from L-REA and H-REA cooking indicated that L-REA had high contents of phenolic hydroxyl groups and carboxylic acid groups in relation to the H-REA pulps. This work demonstrates the varied lignin chemistry one can expect when residual effective alkali levels are varied during kraft pulping and how this parameter can influence downstream unit operations and overall process performance.}, number={12}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Ribeiro, Robisnea Adriana and Vaz Junior, Silvio and Jameel, Hasan and Chang, Hou-Min and Narron, Robert and Jiang, Xiao and Colodette, Jorge Luiz}, year={2019}, month={Jun}, pages={10274–10282} }
 @article{huang_dong_su_wu_narron_yong_2019, title={Synthesis of Carbon Quantum Dot Nanoparticles Derived from Byproducts in Bio-Refinery Process for Cell Imaging and In Vivo Bioimaging}, volume={9}, ISSN={["2079-4991"]}, DOI={10.3390/nano9030387}, abstractNote={The carbon quantum dot (CQD), a fluorescent carbon nanoparticle, has attracted considerable interest due to its photoluminescent property and promising applications in cell imaging and bioimaging. In this work, biocompatible, photostable, and sustainably sourced CQDs were synthesized from byproducts derived from a biorefinery process using one-pot hydrothermal treatment. The main components of byproducts were the degradation products (autohydrolyzate) of biomass pretreated by autohydrolysis. The as-synthesized CQDs had a size distribution from 2.0–6.0 nm and had high percentage of sp2 and sp3 carbon groups. The CQDs showed blue-green fluorescence with a quantum yield of ~13%, and the fluorescence behaviors were found to be stable with strong resistance to photobleaching and temperature change. In addition, it is found that the as-synthesized CQDs could be used for imaging of cells and tumors, which show potential applications in bioimaging and related fields such as phototherapy and imaging.}, number={3}, journal={NANOMATERIALS}, author={Huang, Caoxing and Dong, Huiling and Su, Yan and Wu, Yan and Narron, Robert and Yong, Qiang}, year={2019}, month={Mar} }
 @article{geng_narron_jiang_pawlak_chang_park_jameel_venditti_2019, title={The influence of lignin content and structure on hemicellulose alkaline extraction for non-wood and hardwood lignocellulosic biomass}, volume={26}, ISSN={0969-0239 1572-882X}, url={http://dx.doi.org/10.1007/s10570-019-02261-y}, DOI={10.1007/s10570-019-02261-y}, number={5}, journal={Cellulose}, publisher={Springer Science and Business Media LLC}, author={Geng, Wenhui and Narron, Robert and Jiang, Xiao and Pawlak, Joel J. and Chang, Hou-min and Park, Sunkyu and Jameel, Hasan and Venditti, Richard A.}, year={2019}, month={Jan}, pages={3219–3230} }
 @article{boes_narron_chen_park_vinueza_2017, title={Characterization of biofuel refinery byproduct via selective electrospray ionization tandem mass spectrometry}, volume={188}, ISSN={["1873-7153"]}, DOI={10.1016/j.fuel.2016.10.016}, abstractNote={To achieve economic viability, biorefineries need to increase efficiency through characterization of byproducts for the purpose of valorization. One such byproduct is the liquid stream produced after autohydrolysis pretreatment, autohydrolyzate liquor, which contains valuable organic derivatives of hemicellulose and lignin from biomass. To characterize the autohydrolysis liquor, we employed a novel method for such liquor analysis that uses electrospray ionization and ion dopants in combination with tandem mass spectrometry using a quadrupole–time-of-flight mass spectrometer. Electrospray expands current analysis of such liquors through softer ionization. Ion dopants provide for differentiation of the complex mixture components without requiring derivatization or preliminary separation. The dopants—ammonium chloride and sodium hydroxide—primarily target and enhance ionization of hemicellulosic or lignin derivative species, respectively, based on the species’ differing functionalities. Valuable structural information can be gleaned from these enhanced species by ion isolation and collision-activated dissociation (CAD), which reveals the presence of hemicellulosic or lignin derivative functionalities. These ionization techniques coupled with CAD enabled us to not only confirm the presence of low molecular weight ions, such as vanillin, as previously seen with gas chromatography-mass spectrometry but also expand the characterization to high molecular weight species. This expanded knowledge of the composition of autohydrolyzate liquor opens up the potential to develop lucrative co-products from this stream in a commercial biorefinery.}, journal={FUEL}, author={Boes, Kelsey S. and Narron, Robert H. and Chen, Yufei and Park, Sunkyu and Vinueza, Nelson R.}, year={2017}, month={Jan}, pages={190–196} }
 @article{narron_han_park_chang_jameel_2017, title={Lignocentric analysis of a carbohydrate-producing lignocellulosic biorefinery process}, volume={241}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2017.05.207}, abstractNote={A biologically-based lignocellulosic biorefinery process for obtaining carbohydrates from raw biomass was investigated across six diverse biomasses (three hardwoods & three nonwoods) for the purpose of decoding lignin's influence on sugar production. Acknowledging that lignin could positively alter the economics of an entire process if valorized appropriately, we sought to correlate the chemical properties of lignin within the process to the traditional metrics associated with carbohydrate production-cellulolytic digestibility and total sugar recovery. Based on raw carbohydrate, enzymatic recovery ranged from 40 to 64% w/w and total recovery ranged from 70 to 87% w/w. Using nitrobenzene oxidation to quantify non-condensed lignin structures, it was found that raw hardwoods bearing increasing non-condensed S/V ratios (2.5-5.1) render increasing total carbohydrate recovery from hardwood biomasses. This finding indicates that the chemical structure of hardwood lignin influences the investigated biorefinery process' ability to generate carbohydrates from a given raw hardwood feedstock.}, journal={BIORESOURCE TECHNOLOGY}, author={Narron, Robert H. and Han, Qiang and Park, Sunkyu and Chang, Hou-min and Jameel, Hasan}, year={2017}, month={Oct}, pages={857–867} }
 @article{narron_chang_jameel_park_2017, title={Soluble Lignin Recovered from Biorefinery Pretreatment Hydrolyzate Characterized by Lignin-Carbohydrate Complexes}, volume={5}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.7b02716}, abstractNote={The lignin rendered soluble by lignocellulosic biorefinery pretreatment remains insufficiently understood along the lines of molecular properties and chemical composition. To procure a representative soluble lignin preparation, an aromatic-selective adsorptive resin was utilized. Approximately 90% of soluble lignin could be recovered from autohydrolysis pretreatment hydrolyzate (autohydrolyzate) produced from a hardwood and a nonwood biomass. Adsorbate compositional characterization revealed a befuddling magnitude of carbohydrate in selectively isolated lignin adsorbates. Quantitative structural analysis of the lignin by NMR suggested lignin–carbohydrate complexes (LCCs) as the cause behind the pronounced carbohydrate contents. Analyzed spectra revealed both hardwood and nonwood soluble lignin features of ∼10 total LCC per 100 aromatic rings, with each lignin bearing unique LCC profiles. In addition, native structures remained in large quantities. The improved understanding of hydrolyzate-soluble lignin g...}, number={11}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Narron, Robert H. and Chang, Hou-min and Jameel, Hasan and Park, Sunkyu}, year={2017}, month={Nov}, pages={10763–10771} }
 @misc{narron_kim_chang_jameel_park_2016, title={Biomass pretreatments capable of enabling lignin valorization in a biorefinery process}, volume={38}, ISSN={["1879-0429"]}, DOI={10.1016/j.copbio.2015.12.018}, abstractNote={Recent techno-economic studies of proposed lignocellulosic biorefineries have concluded that creating value from lignin will assist realization of biomass utilization into valuable fuels, chemicals, and materials due to co-valorization and the new revenues beyond carbohydrates. The pretreatment step within a biorefinery process is essential for recovering carbohydrates, but different techniques and intensities have a variety of effects on lignin. Acidic and alkaline pretreatments have been shown to produce diverse lignins based on delignification chemistry. The valorization potential of pretreated lignin is affected by its chemical structure, which is known to degrade, including inter-lignin condensation under high-severity pretreatment. Co-valorization of lignin and carbohydrates will require dampening of pretreatment intensities to avoid such effects, in spite of tradeoffs in carbohydrate production.}, journal={CURRENT OPINION IN BIOTECHNOLOGY}, author={Narron, Robert H. and Kim, Hoyong and Chang, Hou-min and Jameel, Hasan and Park, Sunkyu}, year={2016}, month={Apr}, pages={39–46} }