@article{barrios_parra_venditti_pal_2024, title={Elucidation of temperature-induced water structuring on cellulose surfaces for environmental and energy sustainability}, volume={329}, ISSN={["1879-1344"]}, url={http://dx.doi.org/10.1016/j.carbpol.2024.121799}, DOI={10.1016/j.carbpol.2024.121799}, abstractNote={Optimizing drying energy in the forest products industry is critical for integrating lignocellulosic feedstocks across all manufacturing sectors. Despite substantial efforts to reduce thermal energy consumption during drying, further enhancements are possible. Cellulose, the main component of forest products, is Earth's most abundant biopolymer and a promising renewable feedstock. This study employs all-atom molecular dynamics (MD) simulations to explore the structural dynamics of a small Iβ-cellulose microcrystallite and surrounding water layers during drying. Molecular and atomistic profiles revealed localized water near the cellulose surface, with water structuring extending beyond 8 Å into the water bulk, influencing solvent-accessible surface area and solvation energy. With increasing temperature, there was a ~20 % reduction in the cellulose surface available for interaction with water molecules, and a ~22 % reduction in solvation energy. The number of hydrogen bonds increased with thicker water layers, facilitated by a “bridging” effect. Electrostatic interactions dominated the intermolecular interactions at all temperatures, creating an energetic barrier that hinders water removal, slowing the drying processes. Understanding temperature-dependent cellulose-water interactions at the molecular level will help in designing novel strategies to address drying energy consumption, advancing the adoption of lignocellulosics as viable manufacturing feedstocks.}, journal={CARBOHYDRATE POLYMERS}, author={Barrios, Nelson and Parra, Jose G. and Venditti, Richard A. and Pal, Lokendra}, year={2024}, month={Apr} }
 @article{barrios_smith_venditti_pal_2024, title={Enzyme-assisted dewatering and strength enhancement of cellulosic fibers for sustainable papermaking: A bench and pilot study}, volume={434}, ISSN={["1879-1786"]}, url={https://doi.org/10.1016/j.jclepro.2023.140094}, DOI={10.1016/j.jclepro.2023.140094}, abstractNote={Water removal during paper manufacturing is of primary importance to production rate and cost efficiency for the pulp and paper industry. It is crucial to develop methods to reduce energy consumption by increasing the percent solids in the paper web entering the dryers from the presses. This research aimed to develop a fundamental understanding of the effect of bio-chemo-mechanical pretreatments on a bleached softwood fiber matrix and evaluate the impact on the percent solids of the paper web after pressing. Experiments included enzymatic, refining, and cationic polymer pretreatments on the bleached softwood pulps, followed by laboratory papermaking and determining the equilibrium moisture content (EMC) after pressing and the pulp and paper properties. The combined effect of mild refining, controlled enzymatic pretreatments, and cationic strength aids proved to enhance the water removal during wet pressing (up to 35 % reduction) and increase paper strength (up to 60 % increase). The results of increased solids after pressing were used to calculate the potential reduction in drying energy during paper manufacturing. Energy savings of around 10 % for paper drying could be achieved through fiber matrix modification by bio-chemo-mechanical pretreatment. Enzymatic pretreatments have been conventionally applied before refining as an energy-saving method. However, this research shows that synergistic actions of enzymes added after refining modify the fibers and create the optimal conditions for enhancement in drainage, press dewatering, and paper properties.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Barrios, Nelson and Smith, Madilynn M. and Venditti, Richard A. and Pal, Lokendra}, year={2024}, month={Jan} }
 @misc{rico_mazabel_egurrola_pulido_barrios_marquez_garcia_2024, title={Meta-Analysis and Analytical Methods in Cosmetics Formulation: A Review}, volume={11}, ISSN={["2079-9284"]}, url={https://www.mdpi.com/2079-9284/11/1/1}, DOI={10.3390/cosmetics11010001}, abstractNote={The ever-evolving cosmetic industry requires advanced analytical techniques to explore, understand, and optimize product performance at nano, micro, and macroscopic levels. Nowadays, these insights are crucial for translating microstructure behavior into macroscopic properties. This knowledge is essential to formulate products with a lower carbon footprint and a higher sustainability profile, incorporating, at the same time, natural or biobased raw materials. These raw materials may present challenges for formulators and analytical scientists due to either an inferior performance when compared to their fossil-derived counterparts or higher costs. This comprehensive review covers a spectrum of analytical methodologies employed in cosmetic formulation, including chromatographic analyses, olfactometry, and electronic nose technology. The characterization of product stability involving assessing parameters such as droplet size, zeta potential, viscosity, analytical centrifugation, surface tension, and interfacial tension are also explored. The discussion in this paper extends to the role of rheology in understanding the molecular structure and behavioral dynamics of cosmetic samples. This review concludes with an overview of colorimetric analysis, a crucial aspect related to consumer perception, followed by a discussion on the challenges and opportunities associated with using meta-analysis methodologies in cosmetics. The formulation of cosmetics employing biobased feedstocks is included, highlighting the evolving landscape of cosmetic science and the integration of sustainable practices. This review stands at the interface between a meta-analysis of cosmetics and product performance, which is attained through a detailed examination of each analytical method. The know-how shared serves as a valuable resource for formulators, researchers, and industry professionals for real-world applications in the analytical field of cosmetics formulation.}, number={1}, journal={COSMETICS}, author={Rico, Felipe and Mazabel, Angela and Egurrola, Greciel and Pulido, Juanita and Barrios, Nelson and Marquez, Ronald and Garcia, Johnbrynner}, year={2024}, month={Feb} }
 @article{marquez_barrios_vera_mendez_tolosa_zambrano_li_2023, title={A Perspective on The Synergistic Potential of Artificial Intelligence and Product-Based Learning Strategies in Biobased Materials Education}, volume={44}, ISSN={1749-7728}, url={http://dx.doi.org/10.1016/j.ece.2023.05.005}, DOI={10.1016/j.ece.2023.05.005}, abstractNote={The integration of product-based learning strategies in Materials in Chemical Engineering education is crucial for students to gain the skills and competencies required to thrive in the emerging circular bioeconomy. Traditional materials engineering education has often relied on a transmission teaching approach, in which students are expected to passively receive information from instructors. However, this approach has shown to be inadequate under the current circumstances, in which information is readily available and innovative tools such as artificial intelligence and virtual reality environments are becoming widespread (e.g., metaverse). Instead, we consider that a critical goal of education should be to develop aptitudes and abilities that enable students to generate solutions and products that address societal demands. In this work, we propose innovative strategies, such as product-based learning methods and GPT (Generative Pre-trained Transformer) artificial intelligence text generation models, to modify the focus of a Materials in Chemical Engineering course from non-sustainable materials to sustainable ones, aiming to address the critical challenges of our society. This approach aims to achieve two objectives: first to enable students to actively engage with raw materials and solve real-world challenges, and second, to foster creativity and entrepreneurship skills by providing them with the necessary tools to conduct brainstorming sessions and develop procedures following scientific methods. The incorporation of circular bioeconomy concepts, such as renewable resources, waste reduction, and resource efficiency into the curriculum provides a framework for students to understand the environmental, social, and economic implications in Chemical Engineering. It also allows them to make informed decisions within the circular bioeconomy framework, benefiting society by promoting the development and adoption of sustainable technologies and practices.}, journal={Education for Chemical Engineers}, publisher={Elsevier BV}, author={Marquez, Ronald and Barrios, Nelson and Vera, Ramon and Mendez, Maria E. and Tolosa, Laura and Zambrano, Franklin and Li, Yali}, year={2023}, month={May}, pages={164–180} }
 @article{marquez_ontiveros_barrios_tolosa_palazzo_nardello-rataj_salager_2023, title={Advantages and limitations of different methods to determine the optimum formulation in surfactant-oil-water systems: A review}, volume={9}, ISSN={["1558-9293"]}, url={https://doi.org/10.1002/jsde.12703}, DOI={10.1002/jsde.12703}, abstractNote={The optimum formulation in a surfactant–oil–water (SOW) system is defined as the physicochemical situation at which the surfactant adsorbed at the interface exhibits exactly equal interactions for both oil and water. Identifying the optimum formulation of SOW systems is crucial in various industrial applications, ranging from pharmaceuticals to cosmetics and to petroleum issues like dehydration and enhanced oil recovery. Multiple techniques are available to identify the optimum formulation, often with its own advantages and limitations. In this comprehensive review, we provide an in‐depth analysis of the systematic use of formulation scans to identify the optimum formulation in SOW systems. We critically assess different methods, including conventional ones, such as phase behavior observation, determination of the minimum interfacial tension from equilibrated systems, and the localization of the minimum emulsion stability using formulation scans. We also mention a new promising technique that can be applied in practice, such as oscillating spinning drop interfacial rheology (OSDIR) as well as others that allow an understanding of some structural features of the domains present in the surfactant‐rich phase in SOW systems. Among these methods, dynamic light scattering (DLS), small angle scattering (SAXS and SANS), nuclear magnetic resonance (NMR), X‐ray microcomputed tomography (Micro‐CT), and differential scanning calorimeter (DSC), can be found in the literature. Finally, we discuss potentially unusual behaviors that can appear in complex systems, thus providing guidance on the selection of the most suitable method tailored to the specific application.}, journal={JOURNAL OF SURFACTANTS AND DETERGENTS}, author={Marquez, Ronald and Ontiveros, Jesus F. and Barrios, Nelson and Tolosa, Laura and Palazzo, Gerardo and Nardello-Rataj, Veronique and Salager, Jean Louis}, year={2023}, month={Sep} }
 @article{salem_barrios_jameel_pal_lucia_2023, title={Computational and experimental insights into the molecular architecture of water-cellulose networks}, volume={6}, ISSN={2590-2385}, url={http://dx.doi.org/10.1016/j.matt.2023.03.021}, DOI={10.1016/j.matt.2023.03.021}, abstractNote={The current perspective attempts to provide key insights into several major aspects of water solvation supported by several experimental and computational investigations. It is postulated that water is not just a common solvent from the framework of the molecular level, but in fact can play the role of a co-reactant or induce an “organizational constraint” (e.g., crystallization) to regulate the rate of chemical reactions. The focus of our perspective is to provide insight into these phenomena; we will cast our net toward the formation of putative water molecules' stacking around the three-dimensional network of the cellulose, the most abundant biomaterial on the planet, which is further mitigated by hydrogen bonding and water-cellulose molecular architecture on the morphology, properties, and chemical reactivity of micro- and nanocellulose. Our perspective also introduces the idea of water hydration shells present immediate to the hydrophilic surface of the cellulose that can help articulate water chemistry and the challenges it presents during drying.}, number={5}, journal={Matter}, publisher={Elsevier BV}, author={Salem, Khandoker Samaher and Barrios, Nelson and Jameel, Hasan and Pal, Lokendra and Lucia, Lucian}, year={2023}, month={May}, pages={1366–1381} }
 @article{barrios_marquez_mcdonald_hubbe_venditti_venditti_pal_2023, title={Innovation in lignocellulosics dewatering and drying for energy sustainability and enhanced utilization of forestry, agriculture, and marine resources - A review}, volume={318}, ISSN={0001-8686}, url={http://dx.doi.org/10.1016/j.cis.2023.102936}, DOI={10.1016/j.cis.2023.102936}, abstractNote={Efficient utilization of forestry, agriculture, and marine resources in various manufacturing sectors requires optimizing fiber transformation, dewatering, and drying energy consumption. These processes play a crucial role in reducing the carbon footprint and boosting sustainability within the circular bioeconomy framework. Despite efforts made in the paper industry to enhance productivity while conserving resources and energy through lower grammage and higher machine speeds, reducing thermal energy consumption during papermaking remains a significant challenge. A key approach to address this challenge lies in increasing dewatering of the fiber web before entering the dryer section of the paper machine. Similarly, the production of high-value-added products derived from alternative lignocellulosic feedstocks, such as nanocellulose and microalgae, requires advanced dewatering techniques for techno-economic viability. This critical and systematic review aims to comprehensively explore the intricate interactions between water and lignocellulosic surfaces, as well as the leading technologies used to enhance dewatering and drying. Recent developments in technologies to reduce water content during papermaking, and advanced dewatering techniques for nanocellulosic and microalgal feedstocks are addressed. Existing research highlights several fundamental and technical challenges spanning from the nano- to macroscopic scales that must be addressed to make lignocellulosics a suitable feedstock option for industry. By identifying alternative strategies to improve water removal, this review intends to accelerate the widespread adoption of lignocellulosics as feasible manufacturing feedstocks. Moreover, this review aims to provide a fundamental understanding of the interactions, associations, and bonding mechanisms between water and cellulose fibers, nanocellulosic materials, and microalgal feedstocks. The findings of this review shed light on critical research directions necessary for advancing the efficient utilization of lignocellulosic resources and accelerating the transition towards sustainable manufacturing practices.}, journal={Advances in Colloid and Interface Science}, publisher={Elsevier BV}, author={Barrios, Nelson and Marquez, Ronald and McDonald, J. David and Hubbe, Martin A. and Venditti, Richard A. and Venditti, A. and Pal, Lokendra}, year={2023}, month={Jun}, pages={102936} }
 @article{barrios_garland_leib_hubbe_2023, title={Mechanistic aspects of nanocellulose–cationic starch–colloidal silica systems for papermaking}, volume={22}, ISSN={0734-1415}, url={http://dx.doi.org/10.32964/tj22.2.107}, DOI={10.32964/tj22.2.107}, abstractNote={Optimization of a chemical additive program for a paper machine can require attention to both colloidal charges and kinetic effects. This work considered an additive program with two negatively charged substances (nanofibrillated cellulose [NFC] and colloidal silica) and two positively charged items (cationic starch and cationic acrylamide copolymer retention aid). Results were shown to depend on charge interactions; however, that clearly was not the whole story. Some findings related to cationic demand, dewatering, fine-particle retention, and flocculation among fibers were best explained in terms of at least partly irreversible complexation interactions between the charged entities. Adjustments in ratios between oppositely charged additives, their sequences of addition, and effects of hydrodynamic shear levels all affected the results. In general, the most promising results were obtained at a cationic starch level of 0.25% to 0.5% based on sheet solids in systems where the cationic starch was used as a pretreatment for NFC.}, number={2}, journal={TAPPI Journal}, publisher={TAPPI}, author={Barrios, Nelson and Garland, Larden and Leib, Brandon and Hubbe, Martin}, year={2023}, month={Mar}, pages={107–115} }
 @article{sarder_piner_rios_chacon_artner_barrios_argyropoulos_2022, title={Copolymers of starch, a sustainable template for biomedical applications: A review}, volume={278}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85120877665&partnerID=MN8TOARS}, DOI={10.1016/j.carbpol.2021.118973}, abstractNote={The outstanding versatility of starch offers a source of inspiration for the development of high-performance-value-added biomaterials for the biomedical field, including drug delivery, tissue engineering and diagnostic imaging. This is because starch-based materials can be tailored to specific applications via facile grafting or other chemistries, introducing specific substituents, with starch being effectively the "template" used in all the chemical transformations discussed in this review. A considerable effort has been carried out to obtain specific tailored starch-based grafted polymers, taking advantage of its biocompatibility and biodegradability with appealing sustainability considerations. The aim of this review is to critically explore the latest research that use grafting chemistries on starch for the synthesis of products for biomedical applications. An effort is made in reviewing the literature that proposes synthetic "greener" approaches, the use of enzymes and their immobilized analogues and alternative solvent systems, including water emulsions, ionic liquids and supercritical CO2.}, journal={CARBOHYDRATE POLYMERS}, publisher={Elsevier BV}, author={Sarder, Roman and Piner, Emily and Rios, David Cruz and Chacon, Lisandra and Artner, Mirela Angelita and Barrios, Nelson and Argyropoulos, Dimitris}, year={2022}, month={Feb}, pages={118973} }
 @article{leib_garland_barrios_hubbe_2022, title={Effects of orders of addition in nanocellulose-cationic starch-colloidal silica systems for papermaking}, volume={21}, DOI={10.32964/TJ21.10.572}, abstractNote={Two orders of addition were compared when preparing paper handsheets from recycled copy paper furnish in combination with nanofibrillated cellulose (NFC), cationic starch, colloidal silica, and cationic retention aid (cPAM; cationic polyacrylamide). Faster dewatering and higher fine-particle retention were obtained at equal optimized dosages of additives when the colloidal silica was added last, after addition of the cPAM. The same order of addition also provided a higher gain in the paper’s tensile strength. However, higher paper stiffness was achieved when the colloidal silica was instead added to the NFC, after its pretreatment with cationic starch. Results were consistent with the principle that papermaking additives added shortly before sheetforming tend to have the largest effects on drainage and retention. The results also demonstrated a sensitivity to the relative dosages of positively and negatively charged additives.}, number={10}, journal={TAPPI Journal}, author={Leib, B.D. and Garland, L.J. and Barrios, N.A. and Hubbe, M.A.}, year={2022}, pages={572–579} }
 @article{garland_leib_barrios_hubbe_2022, title={Nanocellulose-cationic starch-colloidal silica systems for papermaking: Effects on process and paper properties}, volume={21}, ISSN={["0734-1415"]}, DOI={10.32964/TJ21.10.563}, abstractNote={Laboratory tests were conducted to better understand effects on the papermaking process and handsheets when recycled copy paper furnish was treated with combinations of nanofibrillated cellulose (NFC), cat-ionic starch, colloidal silica, and cationic retention aid (cPAM; cationic polyacrylamide). Dosage-response experiments helped to define conditions leading to favorable processing outcomes, including dewatering rates and the efficiency of fine-particle retention during papermaking. Effects were found to depend on the addition amounts of cationic starch and colloidal silica added to the system. It was shown that the presence of a polymer additive such as cationic starch was essential in order to achieve large strength gains with simultaneous usage of NFC.}, number={10}, journal={TAPPI Journal}, author={Garland, L.J. and Leib, B.D. and Barrios, N.A. and Hubbe, M.A.}, year={2022}, pages={563–570} }
 @article{barrios_patiño-agudelo_quina_salas_pereira_2022, title={Specific anion effects on the interfacial properties and aggregation of alkylphenol ethoxylate surfactants}, volume={363}, ISSN={["1873-3166"]}, DOI={10.1016/j.molliq.2022.119899}, abstractNote={The effect of Hofmeister anions on aggregation of nonionic surfactants and the formation of microemulsion systems was evaluated. Added salt effects on the interfacial properties and aggregation of ethylene oxide condensates of nonylphenol were characterized by cloud point measurements, surface tension, fluorescence spectroscopy, light scattering, and formulation scans. The specific effects of anions on the cloud point followed the trend predicted by the Hofmeister series: H2PO4− < Cl− < Br− < NO3− < I− < SCN−, with the H2PO4− being the most kosmotropic anion and generating the most significant cloud point reduction. The specific effects of anions on the critical micelle concentration (CMC) also followed the Hofmeister series, with kosmotropic anions causing a decrease and chaotropic anions generating an increase in the CMC. Chaotropic anions decreased the size of the aggregates, while kosmotropic anions increased it, as evaluated by dynamic light scattering. The effect of Hofmeister anions on microemulsion formation in nonionic surfactant-oil–water (SOW) systems was assessed by formulation scans. Although the kosmotropicity of the anion did not influence the optimum formulation value, it did affect the phase behavior around the optimum formulation, pointing to the possibility of tuning microemulsion formulations via the choice of added electrolyte.}, journal={Journal of Molecular Liquids}, author={Barrios, Nelson and Patiño-Agudelo, Álvaro Javier and Quina, Frank Herbert and Salas, Carlos and Pereira, Juan}, year={2022}, month={Oct}, pages={119899} }
 @article{barrios_pereira_salas_2021, title={Block copolymer penetration into an asphaltene film as a mechanism for water-in-crude oil emulsion break-up}, volume={306}, ISSN={["1873-7153"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85113644280&partnerID=MN8TOARS}, DOI={10.1016/j.fuel.2021.121756}, abstractNote={• Results of this work suggest that the demulsifier is only effective at low dosages. • When the subphase consists of 0.154 μM solution of block copolymer, the surface pressure-area isotherms of asphaltene shows the appearance of new phases, L 1 and L 2 . • The contact angle results shows interaction between the asphaltene surface e and the hydrophobic part of the polymer exposed on the drop. During crude oil extraction, asphaltene-stabilized water-in-oil emulsions are formed and make the dewatering a challenging task. Demulsifiers (surface active agents), are typically used to destabilize the emulsion and facilitate the coalescence of water droplets. The demulsification mechanism of asphaltene-stabilized water-in-toluene emulsions by an ethylene oxide-propylene oxide-ethylene oxide (EO 37 ─PO 56 ─EO 37 ) based block copolymer was studied. The performance of the demulsifier was assessed by bottle tests and the interfacial properties were determined by means of interfacial tension, Langmuir trough and contact angle measurements. From bottle tests experiments, the demulsifier showed the best performance at 3.85 µM in the water phase. A concentration dependent disruption of an asphaltene monolayer onto an aqueous polymeric surfactant subphase, was observed by means of Langmuir trough experiments. An interesting breakpoint was found at 0.154 µM aqueous polymeric surfactant concentration in the surface pressure-area isotherm, which is attributed to the formation of a new phase. Contact angle measurements of drops of aqueous polymeric surfactant solution onto asphaltene films showed that, at increasing polymeric surfactant concentration, the contact angle diminished to a threshold value. A direct interaction of block copolymer with asphaltene is proposed as a mechanism to account for the destabilization of water-in-oil emulsions.}, journal={FUEL}, author={Barrios, Nelson and Pereira, Juan and Salas, Carlos}, year={2021}, month={Dec} }
 @article{jorge_pereira_rodriguez_barrios_oliva_antonio_2018, title={Impedance spectroscopy in water/oil emulsions in a range of intermediate frequencies}, volume={25}, number={3}, journal={Ingenieŕıa UC}, author={Jorge, José and Pereira, JC and Rodriguez, Maria and Barrios, Nelson and Oliva, David and Antonio, José}, year={2018}, pages={388–395} }
 @article{bari_pereira_barrios_2014, title={Estudio del Punto de Turbidez de los surfactantes no-iónicos en solución acuosa: efecto de la concentración}, volume={21}, url={https://www.redalyc.org/articulo.oa?id=70732656009}, number={2}, journal={Revista INGENIERÍA UC}, author={Bari, A. and Pereira, J.C. and Barrios, N.A.}, year={2014}, month={May}, pages={66–72} }