Exploració per autor "Rojas, Orlando J."

Ara es mostren els items 1-15 de 15

    • A facile and green method to hydrophobize films of cellulose nanofibrils and silica by laccase-mediated coupling of nonpolar colloidal particles 

      Cusola Aumedes, Oriol; Roncero Vivero, María Blanca; Vidal Lluciá, Teresa; Rojas, Orlando J. (2014-10-01)
      Article
      Accés restringit per política de l'editorial
      Hydrophobic particles based on dodecyl 3,4,5-trihydroxybenzoate (LG) were coupled onto the surface of cellulose nanofibrils (CNFs) and silica by treatment with a multicomponent colloidal system (MCS) derived from the ...

    • Alternative chemo-enzymatic treatment for homogeneous and heterogeneous acetylation of wood fibers 

      Quintana, Elisabet; Ago, Mariko; Valls Vidal, Cristina; Roncero Vivero, María Blanca; Rojas, Orlando J. (2018-07-18)
      Article
      Accés obert
      A new chemo-enzymatic treatment is proposed to produce cellulosic fibers suitable for heterogeneous- or homogeneous-phase acetylation. The procedure included enzymatic (laccase–violuric acid) lignin removal from the precursor ...

    • Cellulose acetate films from chemo-enzymatic dissolving pulps 

      Quintana, Elisabet; Ago, Mariko; Valls Vidal, Cristina; Fernández Santos, Julia; Roncero Vivero, María Blanca; Rojas, Orlando J. (2022)
      Comunicació de congrés
      Accés obert
      The purpose of this work is to obtain dissolving cellulose fibers that are suitable for the manufacturing of cellulose derivatives. Therefore, the combination of enzymatic and chemical treatments during the bleaching stage ...

    • Effect of residual lignin and heteropolysaccharides in nanofibrillar cellulose and nanopaper from wood fibers 

      Ferrer Carrera, Ana; Quintana, Elisabet; Filpponen, Ilari; Solala, Iina; Vidal Lluciá, Teresa; Rodríguez Pascual, Alejandro; Laine, Janne; Rojas, Orlando J. (2012-12)
      Article
      Accés restringit per política de l'editorial
      Unbleached (UN), oxygen-delignified and fully-bleached (FB) birch fibers with a residual lignin content of ca. 3, 2 and\1 %, respectively, were used to produce nanofibrillated cellulose (NFC) and nanopaper by using an ...

    • Functionalization of cellulosic model substrates via laccase-mediated coupling of non-polar particles 

      Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Lluciá, Teresa; Roncero Vivero, María Blanca; Rojas, Orlando J. (2014)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      In the present work we investigate the physicochemical interactions between silica and nanofibrillar cellulose (CNF) with a multi component system (MCS) obtained from an enzymatic reaction of a laccase enzyme and a short-chain ...

    • Laccase-mediated coupling of nonpolar chains for the hydrophobization of lignocellulose 

      García Ubasart, Jordi; Vidal Lluciá, Teresa; Torres López, Antonio Luis; Rojas, Orlando J. (2013-04-09)
      Article
      Accés restringit per política de l'editorial
      We investigate the use of laccase enzymes to couple short nonpolar chains containing aromatic groups onto flax fibers and nanofibrillated cellulose (NFC) with different lignin contents. Trametes villosa, Pycnoporus ...

    • Lignin particles for multifunctional membranes, antioxidative microfiltration, patterning and 3D structuring 

      Cusola Aumedes, Oriol; Rojas, Orlando J.; Roncero Vivero, María Blanca (2019-11-08)
      Article
      Accés obert
      We introduce a new type of particle-based membrane based on the combination of lignin particles (LPs) and cellulose nanofibrils (CNF), the latter of which are introduced in small volume fractions to act as networking and ...

    • Nanofiber composites of polyvinyl alcohol and cellulose nanocrystals: manufacture and characterization 

      Peresin, Maria; Habibi, Youssef; Zoppe, Justin Orazio; Pawlak, Joel; Rojas, Orlando J. (2010-03-08)
      Article
      Accés restringit per política de l'editorial
      Cellulose nanocrystals (CN) were used to reinforce nanofibers in composite mats produced via electrospinning of poly(vinyl alcohol) (PVA) with two different concentrations of acetyl groups. Ultrathin cross-sections of the ...

    • Nanofibrillar networks enable universal assembly of superstructured particle constructs 

      Mattos, Bruno D.; Tardy, Blaise L.; Greca, Luiz G.; Kämäräinen, Tero; Xiang, Wenchao; Cusola Aumedes, Oriol; Magalhães, Washington; Rojas, Orlando J. (2020-05-08)
      Article
      Accés obert
      Superstructured colloidal materials exploit the synergies between components to develop new or enhanced functions. Cohesion is a primary requirement for scaling up these assemblies into bulk materials, and it has only been ...

    • Particulate coatings via evaporation-induced self-assembly of polydisperse colloidal lignin on solid interfaces 

      Cusola Aumedes, Oriol; Kivistö, Samu; Vierros, Sampsa; Batys, Piotr; Ago, Mariko; Tardy, Blaise L.; Greca, Luiz G.; Roncero Vivero, María Blanca; Sammalkorpi, Maria; Rojas, Orlando J. (2018-05-02)
      Article
      Accés restringit per política de l'editorial
      Polydisperse smooth and spherical biocolloidal particles were suspended in aqueous media and allowed to consolidate via evaporation-induced self-assembly. The stratification of the particles at the solid–air interface was ...

    • Pickering emulsions stabilized by cellulose nanocrystals grafted with thermo-responsive polymer brushes 

      Zoppe, Justin Orazio; Venditti, Richard A.; Rojas, Orlando J. (2012-03)
      Article
      Accés obert
      Cellulose nanocrystals (CNCs) from ramie fibers are studied as stabilizers of oil-in-water emulsions. The phase behavior of heptane and water systems is studied, and emulsions stabilized by CNCs are analyzed by using drop ...

    • Poly(N-isopropylacrylamide) brushes grafted from cellulose nanocrystals via surface-initiated single-electron transfer living radical polymerization 

      Zoppe, Justin Orazio; Habibi, Youssef; Rojas, Orlando J.; Venditti, Richard A.; Johansson, Leena-Sisko; Efimenko, Kirill; Osterberg, Monika; Laine, Janne (2010-10-11)
      Article
      Accés obert
      Cellulose nanocrystals (CNCs) or nanowhiskers produced from sulfuric acid hydrolysis of ramie fibers were used as substrates for surface chemical functionalization with thermoresponsive macromolecules. The CNCs were grafted ...

    • Recerca i tecnologia en enginyeria gràfica i disseny a la Universitat Politècnica de Catalunya 

      García Carrillo, Àgueda; Ramos Cabal, Alba; Datas Medina, Alejandro; Sureda Carbonell, Bàrbara; Faura López de Haro, Bernat; del Cañizo Nadal, Carlos; Valls Vidal, Cristina; Hernández Díaz, David; Mestres Domenech, Francesc; Bermúdez Rodríguez, Francisco; Hernández Abad, Francisco; Peña Andrés, Javier; Ivern Cacho, Jordi; Lapaz Castillo, José Luís; Ibáñez García, José María; Roncero Vivero, María Blanca; López Membrilla, Manuel; Alcaraz Sendra, Olga; Cusola Aumedes, Oriol; Rojas, Orlando J.; Farrerons Vidal, Óscar; Villar Ribera, Ricardo Alberto; Baltà Salvador, Rosó; Castro de Losada, Rubén de; Hernández Abad, Vicente (OmniaScience, 2020-03-02)
      Llibre
      Accés obert
      Els temps canvien cada vegada més ràpidament, i a la universitat això encara es nota més. L’històric departament d‘Expressió Gràfica a l’Enginyeria (EGE) de la Universitat Politècnica de Catalunya, garant d’una docència ...

    • Reinforcing Poly(e-caprolactone) nanofibers with cellulose nanocrystals 

      Zoppe, Justin Orazio; Peresin, Maria Soledad; Habibi, Youssef; Venditti, Richard A.; Rojas, Orlando J. (2009-09-30)
      Article
      Accés obert
      We studied the use of cellulose nanocrystals (CNXs) obtained after acid hydrolysis of ramie cellulose fibers to reinforce poly(e-caprolactone) (PCL) nanofibers. Chemical grafting with low-molecular-weight PCL diol onto the ...

    • Surface interaction forces of cellulose nanocrystals grafted with thermoresponsive polymer brushes 

      Zoppe, Justin Orazio; Osterberg, Monika; Venditti, Richard A.; Laine, Janne; Rojas, Orlando J. (2011-07-11)
      Article
      Accés obert
      The colloidal stability and thermoresponsive behavior of poly(N-isopropylacrylamide) brushes grafted from cellulose nanocrystals (CNCs) of varying graft densities and molecular weights was investigated. Indication of the ...