Publications by authors named "Daniel Pasquini"

12 Publications

  • Page 1 of 1

Improved Hydrophobicity of Macroalgae Biopolymer Film Incorporated with Kenaf Derived CNF Using Silane Coupling Agent.

Molecules 2021 Apr 13;26(8). Epub 2021 Apr 13.

Chemistry Institute, Federal University of Uberlandia-UFU, Uberlândia 38400-902, Brazil.

Hydrophilic behaviour of carrageenan macroalgae biopolymer, due to hydroxyl groups, has limited its applications, especially for packaging. In this study, macroalgae were reinforced with cellulose nanofibrils (CNFs) isolated from kenaf bast fibres. The macroalgae CNF film was after that treated with silane for hydrophobicity enhancement. The wettability and functional properties of unmodified macroalgae CNF films were compared with silane-modified macroalgae CNF films. Characterisation of the unmodified and modified biopolymers films was investigated. The atomic force microscope (AFM), SEM morphology, tensile properties, water contact angle, and thermal behaviour of the biofilms showed that the incorporation of Kenaf bast CNF remarkably increased the strength, moisture resistance, and thermal stability of the macroalgae biopolymer films. Moreover, the films' modification using a silane coupling agent further enhanced the strength and thermal stability of the films apart from improved water-resistance of the biopolymer films compared to unmodified films. The morphology and AFM showed good interfacial interaction of the components of the biopolymer films. The modified biopolymer films exhibited significantly improved hydrophobic properties compared to the unmodified films due to the enhanced dispersion resulting from the silane treatment. The improved biopolymer films can potentially be utilised as packaging materials.
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http://dx.doi.org/10.3390/molecules26082254DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8069814PMC
April 2021

A Review on Plant Cellulose Nanofibre-Based Aerogels for Biomedical Applications.

Polymers (Basel) 2020 Aug 6;12(8). Epub 2020 Aug 6.

Chemistry Institute, Federal University of Uberlandia-UFU, Campus Santa Monica-Bloco1D-CP 593, Uberlandia 38400-902, Brazil.

Cellulose nanomaterials from plant fibre provide various potential applications (i.e., biomedical, automotive, packaging, etc.). The biomedical application of nanocellulose isolated from plant fibre, which is a carbohydrate-based source, is very viable in the 21st century. The essential characteristics of plant fibre-based nanocellulose, which include its molecular, tensile and mechanical properties, as well as its biodegradability potential, have been widely explored for functional materials in the preparation of aerogel. Plant cellulose nano fibre (CNF)-based aerogels are novel functional materials that have attracted remarkable interest. In recent years, CNF aerogel has been extensively used in the biomedical field due to its biocompatibility, renewability and biodegradability. The effective surface area of CNFs influences broad applications in biological and medical studies such as sustainable antibiotic delivery for wound healing, the preparation of scaffolds for tissue cultures, the development of drug delivery systems, biosensing and an antimicrobial film for wound healing. Many researchers have a growing interest in using CNF-based aerogels in the mentioned applications. The application of cellulose-based materials is widely reported in the literature. However, only a few studies discuss the potential of cellulose nanofibre aerogel in detail. The potential applications of CNF aerogel include composites, organic-inorganic hybrids, gels, foams, aerogels/xerogels, coatings and nano-paper, bioactive and wound dressing materials and bioconversion. The potential applications of CNF have rarely been a subject of extensive review. Thus, extensive studies to develop materials with cheaper and better properties, high prospects and effectiveness for many applications are the focus of the present work. The present review focuses on the evolution of aerogels via characterisation studies on the isolation of CNF-based aerogels. The study concludes with a description of the potential and challenges of developing sustainable materials for biomedical applications.
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http://dx.doi.org/10.3390/polym12081759DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465206PMC
August 2020

Ultra-fast heat dissipating aerogels derived from polyaniline anchored cellulose nanofibers as sustainable microwave absorbers.

Carbohydr Polym 2020 Oct 17;246:116663. Epub 2020 Jun 17.

International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala 686560, India; School of Chemical Sciences, Mahatma Gandhi University, Kottayam, Kerala 686560, India. Electronic address:

Electromagnetic (EM) pollution is ubiquitous and has soared to a great extent in the past few decades. The use of plant sourced cellulose nanofibers to fabricate sustainable and high performance electromagnetic shielding materials is foreseen as a green solution by the electronics industry to address this unseen pollutant. In this view, we report a facile and environmentally benign strategy to synthesize ultra-light and highly conductive aerogels derived from cellulose nanofibers (CNF) decorated with polyaniline (PANI) via a simple in-situ polymerization and subsequent freeze drying process devoid of any volatile organic solvents. The obtained conductive aerogels exhibited density as low as 0.01925 g/cc with a maximum EMI shielding value -32 dB in X band region. These porous shields demonstrated strong microwave absorption behavior (95 %) with minimal reflection (5 %) coupled with high specific EMI SE value ∼1667 dB.cm. g which make these aerogels a potential candidate for use in telecommunication, military and defense applications.
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http://dx.doi.org/10.1016/j.carbpol.2020.116663DOI Listing
October 2020

Ethanol Production and Other Bioproducts by Galactomyces geotrichum from Sugarcane Bagasse Hydrolysate.

Curr Microbiol 2020 May 8;77(5):738-745. Epub 2020 Jan 8.

Federal University of Uberlândia, Agricultural Sciences Institute (ICIAG-UFU), Uberlândia, Minas Gerais, 38405-320, Brazil.

This study investigated the enzymatic saccharification of alkaline-pretreated sugarcane bagasse (PSB) and the bioconversion of simple sugars from hydrolysates to ethanol and other bioproducts by the yeast Galactomyces geotrichum. The effects of percentage of dry substrate (3 and 10% w/v) and time of hydrolysis (24 and 72 h) in the content of released sugars were evaluated. The concentrations of monosaccharides and total reducing sugars (TRS) were calculated by high-performance liquid chromatography (HPLC) and by 3.5-dinitrosalicylic acid (DNS) method, respectively. The highest concentrations of TRS, glucose and xylose (73.96, 31.78 and 10.85 g/L, respectively) were obtained after the saccharification of 10% of PSB with Cellic CTec3 multi-enzyme cocktail (10 FPU/g cellulose) during 72 h (hydrolysate IV). G. geotrichum UFVJM-R150 fermented both glucose and xylose from the hydrolysates. The most efficient ethanol production was obtained after the fermentation of hydrolysate IV (9.99 g/L of ethanol, volumetric productivity-Q of 0.42 g/L.h and yield of ethanol as a function of the substrate-Y of 0.27 g/g). Besides ethanol, G. geotrichum was also able to produce other high-value chemicals such as isoamyl alcohol and galacturonic acid. This is the first report of the potential of the yeast G. geotrichum to fermentate sugarcane bagasse hydrolysates with the production of important bioproducts to further use by biorefineries.
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http://dx.doi.org/10.1007/s00284-019-01866-7DOI Listing
May 2020

Robust Superhydrophobic Cellulose Nanofiber Aerogel for Multifunctional Environmental Applications.

Polymers (Basel) 2019 Mar 14;11(3). Epub 2019 Mar 14.

School of Industrial Technology, Universiti Sains Malaysia, Penang 11800, Malaysia.

The fabrication of superadsorbent for dye adsorption is a hot research area at present. However, the development of low-cost and highly efficient superadsorbents against toxic textile dyes is still a big challenge. Here, we fabricated hydrophobic cellulose nanofiber aerogels from cellulose nanofibers through an eco-friendly silanization reaction in liquid phase, which is an extremely efficient, rapid, cheap, and environmentally friendly procedure. Moreover, the demonstrated eco-friendly silanization technique is easy to commercialize at the industrial level. Most of the works that have reported on the hydrophobic cellulose nanofiber aerogels explored their use for the elimination of oil from water. The key novelty of the present work is that the demonstrated hydrophobic cellulose nanofibers aerogels could serve as superadsorbents against toxic textile dyes such as crystal violet dye from water and insulating materials for building applications. Here, we make use of the possible hydrophobic interactions between silane-modified cellulose nanofiber aerogel and crystal violet dye for the removal of the crystal violet dye from water. With a 10 mg/L of crystal violet (CV) aqueous solution, the silane-modified cellulose nanofiber aerogel showed a high adsorption capacity value of 150 mg/g of the aerogel. The reason for this adsorption value was due to the short-range hydrophobic interaction between the silane-modified cellulose nanofiber aerogel and the hydrophobic domains in crystal violet dye molecules. Additionally, the fabricated silane-modified cellulose nanofiber hydrophobic aerogels exhibited a lower thermal conductivity value of 0.037 W·m K, which was comparable to and lower than the commercial insulators such as mineral wools (0.040 W·m K) and polystyrene foams (0.035 W·m K). We firmly believe that the demonstrated silane-modified cellulose nanofiber aerogel could yield an eco-friendly adsorbent that is agreeable to adsorbing toxic crystal violet dyes from water as well as active building thermal insulators.
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http://dx.doi.org/10.3390/polym11030495DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473771PMC
March 2019

Use of an (Hemi) Cellulolytic Enzymatic Extract Produced by Aspergilli Species Consortium in the Saccharification of Biomass Sorghum.

Appl Biochem Biotechnol 2019 Sep 13;189(1):37-48. Epub 2019 Mar 13.

Agricultural Sciences Institute (ICIAG-UFU), Uberlândia Federal University, Uberlândia, Minas Gerais, 38405-320, Brazil.

This study evaluated the production of lignocellulose-degrading enzymes by solid-state fermentation (SSF) using a microbial consortium of Aspergillus fumigatus SCBM6 and A. niger SCBM1 (AFN extract). The fungal strains were cultivated in sugarcane bagasse (SCB) and wheat bran (WB) as lignocellulosic substrates for 7 days at 30 °C. After SSF, the highest peaks of enzyme production were 150 and 80 U g for β-xylosidase and β-glucosidase at 48 h, 375 U g for xylanase at 96 h, and 80 U g for endoglucanase and 4 U g for cellulase activity on filter paper (FPase) at 144 h. The efficiency of the produced AFN extract was investigated in the enzymatic hydrolysis of crude biomass sorghum (BS) and after the removal of extractives (ES). After saccharification, the glucose and xylose concentrations were 10× superior in ES than in BS hydrolysate (2.5 g L after 12 h). The presence of inhibitors of alcoholic fermentation, such as formic acid, was also reduced in ES hydrolysates, indicating that the removal of extractives positively contributed to the effectiveness of enzymatic hydrolysis of biomass sorghum using AFN extract.
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http://dx.doi.org/10.1007/s12010-019-02991-6DOI Listing
September 2019

Polymeric blends of hydrocolloid from chia seeds/apple pectin with potential antioxidant for food packaging applications.

Carbohydr Polym 2018 Dec 20;202:203-210. Epub 2018 Aug 20.

Instituto de Química, Universidade Federal de Uberlândia, Campus Santa Mônica, Av. João Naves de Ávila, 2121, 38400-902, Uberlândia, Minas Gerais, Brazil. Electronic address:

The aim of this study was to investigate the antioxidant, mechanical and physical properties of a new film-based polymeric blend of hydrocolloids obtained from the aqueous extraction of chia seeds (source antioxidants) and apple pectin. The individual matrices films were brittle and rigid with poor mechanical properties. The blends formulations contributed to improved mechanical properties regarding workability and resistance. The antioxidant results showed the potential hydrocolloid from chia seeds as natural source of antioxidant in these polymeric films. The formulation 3 (14(hydrocolloid):41(pectin):25(glycerol):20(glutaraldehyde) displayed well thermal, mechanical, morphological and antioxidant properties, suggesting their great potential for food packaging.
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http://dx.doi.org/10.1016/j.carbpol.2018.08.061DOI Listing
December 2018

Cellulose Nanofiber-Based Polyaniline Flexible Papers as Sustainable Microwave Absorbers in the X-Band.

ACS Appl Mater Interfaces 2018 Jun 29;10(23):20032-20043. Epub 2018 May 29.

International and Inter University Centre for Nanoscience and Nanotechnology , Mahatma Gandhi University , Kottayam , Kerala 686560 , India.

A series of flexible, lightweight, and highly conductive cellulose nanopapers were fabricated through in situ polymerization of aniline monomer on to cellulose nanofibers with a rationale for attenuating electromagnetic radiations within 8.2-12.4 GHz (X band). The demonstrated paper exhibits good conductivity due to the formation of a continuous coating of polyaniline (PANI) over the cellulose nanofibers (CNF) during in situ polymerization, which is evident from scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. The free hydroxyl groups on the surface of nanocellulose fibers promptly form intermolecular hydrogen bonding with PANI, which plays a vital role in shielding electromagnetic radiations and makes the cellulose nanopapers even more robust. These composite nanopapers exhibited an average shielding effectiveness of ca. -23 dB (>99% attenuation) at 8.2 GHz with 1 mm paper thickness. The fabricated papers exhibited an effective attenuation of electromagnetic waves by a predominant absorption mechanism (ca. 87%) rather than reflection (ca. 13%), which is highly desirable for the present-day telecommunication sector. Unlike metal-based shields, these demonstrated PANI/CNF papers have given a new platform for designing green microwave attenuators via an absorption mechanism. The prime novelty of the present study is that these robust PANI/CNF nanopapers have the ability to attenuate incoming microwave radiations to an extent that is 360% higher than the shielding effectiveness value reported in the previous literature. This makes them suitable for use in commercial electronic gadgets. This demonstrated work also opens up new avenues for using cellulose nanofibers as an effective substrate for fabricating conductive flexible papers using polyaniline. The direct current conductivity value of PANI/CNF nanopaper was 0.314 S/cm, which is one of the key requisites for the fabrication of efficient electromagnetic shields. Nevertheless, such nanopapers also open up an arena of applications such as electrodes for supercapacitors, separators for Li-S, Li-polymer batteries, and other freestanding flexible paper-based devices.
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http://dx.doi.org/10.1021/acsami.8b04549DOI Listing
June 2018

Mechanical properties of natural rubber nanocomposites reinforced with high aspect ratio cellulose nanocrystals isolated from soy hulls.

Carbohydr Polym 2016 Nov 19;153:143-152. Epub 2016 Jul 19.

Univ. Grenoble Alpes, LGP2, F-38000 Grenoble, France; CNRS, LGP2, F-38000 Grenoble, France. Electronic address:

Cellulose nanocrystals (CNCs) were isolated from soy hulls by acid sulfuric hydrolysis. The resulting CNCs were characterized using TEM, AFM, WAXS, elemental analysis and TGA. The CNCs have a high crystallinity, specific surface area and aspect ratio. The aspect ratio (around 100) is the largest ever reported in the literature for a plant cellulose source. These CNCs were used as a reinforcing phase to prepare nanocomposite films by casting/evaporation using natural rubber as matrix. The mechanical properties were studied in both the linear and non-linear ranges. The reinforcing effect was higher than the one observed for CNCs extracted from other sources. It may be assigned not only to the high aspect ratio of these CNCs but also to the stiffness of the percolating nanoparticle network formed within the polymer matrix. Moreover, the sedimentation of CNCs during the evaporation step was found to play a crucial role on the mechanical properties.
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http://dx.doi.org/10.1016/j.carbpol.2016.07.073DOI Listing
November 2016

Valorization of an agro-industrial waste, mango seed, by the extraction and characterization of its cellulose nanocrystals.

J Environ Manage 2013 May 29;121:202-9. Epub 2013 Mar 29.

Instituto de Química, Universidade Federal de Uberlândia, Campus Santa Mônica, Av. João Naves de Ávila, 2121, 38400-902 Uberlândia, Minas Gerais, Brazil.

Mango seeds are lignocellulosic agro-industrial residues available in large quantities in tropical countries and are simply discarded or used as animal feed. They are a natural and renewable resource, and were used to generate new polymeric materials in this work. This new materials can be used as alternatives to fossil resources such as petroleum. This work aimed to extract and characterize cellulose nanocrystals (CN) from mango seed by acid hydrolysis to obtain a material suitable as a reinforcing agent in the manufacturing of nanocomposites. The fibers of mango seeds were ground in mills and purified mainly to remove lignin. The raw mango seed (MS) and the purified mango seed (PMS) were analyzed for chemical composition and characterized by infrared and X-rays. Cellulose nanocrystals from the mango seed (CNM) were isolated by acid hydrolysis at 40 °C for 10 min, with 20 ml of H2SO4 (11.21 M) used for every gram of cellulose. The yield at this step was 22.8%. CNM were needle-shaped, with high crystallinity (90.6%), good thermal stability (around 248 °C), a medium length (L) of 123.4 ± 22.1 nm and a diameter (D) of 4.59 ± 2.22 nm, giving an aspect ratio (L/D) of about 34.1 ± 18.6. The diameter measurements of CNM were also confirmed by Scherrer's equation. This work also aimed to reuse mango seed produced as industrial waste, giving it a useful application and preventing its role as an environmental pollutant.
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http://dx.doi.org/10.1016/j.jenvman.2013.02.054DOI Listing
May 2013

Physical vapor deposited thin films of lignins extracted from sugar cane bagasse: morphology, electrical properties, and sensing applications.

Biomacromolecules 2011 Sep 28;12(9):3223-31. Epub 2011 Jul 28.

Faculdade de Ciências e Tecnologia, UNESP Univ Estadual Paulista, Presidente Prudente/SP, 19060-900, Brazil.

The concern related to the environmental degradation and to the exhaustion of natural resources has induced the research on biodegradable materials obtained from renewable sources, which involves fundamental properties and general application. In this context, we have fabricated thin films of lignins, which were extracted from sugar cane bagasse via modified organosolv process using ethanol as organic solvent. The films were made using the vacuum thermal evaporation technique (PVD, physical vapor deposition) grown up to 120 nm. The main objective was to explore basic properties such as electrical and surface morphology and the sensing performance of these lignins as transducers. The PVD film growth was monitored via ultraviolet-visible (UV-vis) absorption spectroscopy and quartz crystal microbalance, revealing a linear relationship between absorbance and film thickness. The 120 nm lignin PVD film morphology presented small aggregates spread all over the film surface on the nanometer scale (atomic force microscopy, AFM) and homogeneous on the micrometer scale (optical microscopy). The PVD films were deposited onto Au interdigitated electrode (IDE) for both electrical characterization and sensing experiments. In the case of electrical characterization, current versus voltage (I vs V) dc measurements were carried out for the Au IDE coated with 120 nm lignin PVD film, leading to a conductivity of 3.6 × 10(-10) S/m. Using impedance spectroscopy, also for the Au IDE coated with the 120 nm lignin PVD film, dielectric constant of 8.0, tan δ of 3.9 × 10(-3), and conductivity of 1.75 × 10(-9) S/m were calculated at 1 kHz. As a proof-of-principle, the application of these lignins as transducers in sensing devices was monitored by both impedance spectroscopy (capacitance vs frequency) and I versus time dc measurements toward aniline vapor (saturated atmosphere). The electrical responses showed that the sensing units are sensible to aniline vapor with the process being reversible. AFM images conducted directly onto the sensing units (Au IDE coated with 120 nm lignin PVD film) before and after the sensing experiments showed a decrease in the PVD film roughness from 5.8 to 3.2 nm after exposing to aniline.
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http://dx.doi.org/10.1021/bm200704mDOI Listing
September 2011

Surface esterification of cellulose fibers: characterization by DRIFT and contact angle measurements.

J Colloid Interface Sci 2006 Mar 25;295(1):79-83. Epub 2005 Aug 25.

Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970 São Carlos, S.P., Brazil.

The surface chemical modification of microcrystalline cellulose and cellulose fibers obtained from different sugar cane bagasse pulping processes, viz. Kraft, organosolv ethanol/water and organosolv/supercritical carbon dioxide, were studied in heterogeneous conditions using modest amounts of octadecanoyl and dodecanoyl chloride. The ensuing surfaces acquired a non-polar character, suitable for incorporating these fibers as reinforcing agents in composite materials based on polymeric matrices. The success of these chemical modifications was assessed by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, elemental analysis, scanning electron microscopy (SEM) and contact angle measurements. In particular, the dynamic and equilibrium contact angle measurements, before and after the treatments, revealed that the value of the polar component (gamma(s)p) of the surface energy had decreased very considerably following the modification.
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http://dx.doi.org/10.1016/j.jcis.2005.07.074DOI Listing
March 2006
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