Antonio J. F. Carvalho

Journal of Renewable Materials, Vol.2, No.2, pp. 118-122, 2014, DOI:10.7569/JRM.2014.634108

Abstract Two nanocelluloses from eucalyptus, namely microfi brillated cellulose (MFC) and cellulose nanocrystals (CNC), were prepared and compared by transmission electron microscopy (TEM). The MFC fi bers are 20–30 nm wide and are composed of very homogeneous bundles of aligned regular elementary fi brils of 3–5 nm diameter. They show long straight portions and short fl exible zones, attributed to crystalline and amorphous zones, respectively. The needle-shaped CNC was approximately 200 nm long and 10 nm wide in the wider portion. A model for the MFC structure, whose fl exible zones are formed by alignment of the amorphous portion of the… More >

Aparecido Junior de Menezes^1,3,*, Elson Longo², Fábio Lima Leite¹, Alain Dufresne³

Journal of Renewable Materials, Vol.2, No.4, pp. 306-313, 2014, DOI:10.7569/JRM.2014.634121

Abstract In the work presented in this article surface chemical modifi cation was applied to ramie cellulose nanocrystals by grafting organic acid chlorides presenting different lengths of the aliphatic chain. The objective of this surface chemical treatment was to enhance the nonpolar nature of the grafted nanocrystals and improve their dispersibility in a nonpolar polymeric matrix. The occurrence of the chemical modifi cation was evaluated by Fourier transform infrared (FTIR) spectroscopy, the degree of crystallinity by X-ray diffraction, and the morphology by scanning electron microscopy with fi eld emission gun (FEG-SEM) and atomic force microscopy (AFM). The morphology and crystallinity provided… More >

Mohammad Jawaid¹, Lau Kia Kian¹, Hassan Fouad², Ramzi Khiari^3,4,5,*, Othman Y. Alothman⁶, Mohamed Hashem⁷

Journal of Renewable Materials, Vol.10, No.6, pp. 1459-1470, 2022, DOI:10.32604/jrm.2022.018415

Abstract Cellulose nanocrystal (CNC) is a biomaterial derived from plant lignocellulosic components, widely applied in various industrial fields. Concurrently, with the growth of awareness in developing green nanomaterial, the explored Washingtonia fibre could be alternative biomass for obtaining CNC products. In the present work, different acid concentrations of 5%, 15%, and 25% hydrochloric solutions were employed to produce CNCs from Washingtonia fibre. With the chemical treatments, the yield of the CNC product was successfully retained at 21.6%−25.1%. Individually separated and needle-shaped CNC particles could be observed under the microscopic viewing with the increased acid concentrations. From elemental analysis, a relatively pure… More > Graphic Abstract

Deniz Sema Sarul¹, Dogan Arslan², Emre Vatansever¹, Yusuf Kahraman², Ali Durmus³, Reza Salehiyan⁴, Mohammadreza Nofar^1,2,*

Journal of Renewable Materials, Vol.10, No.1, pp. 149-164, 2022, DOI:10.32604/jrm.2022.017003

Abstract Polylactide (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend nanocomposites including 3 wt% of cellulose nanocrystals (CNCs) were prepared by melt compounding method in a twin-screw extruder and an internal mixer. Blend nanocomposites were formulated by diluting three different masterbatches prepared by solution casting method that contained 7 wt% of CNC. These masterbatches were: (m1) PLA/PBAT/CNC masterbatch; (m2) PLA/CNC masterbatch; and (m3) PBAT/CNC masterbatch. These were to explore how different preparation methods affect the dispersion and localization of CNC and hence the properties of PLA/PBAT/CNC blend nanocomposites. Scanning electron microscopy (SEM) was used to study the structural changes of the blends. Rheological properties… More >

Ewa Szefer^*, Agnieszka Leszczyńska, Edyta Hebda, Krzysztof Pielichowski

Journal of Renewable Materials, Vol.9, No.6, pp. 1127-1142, 2021, DOI:10.32604/jrm.2021.014584

Abstract The aim of this work was to use cellulose nanocrystals that were obtained by hydrolysis in phosphoric acid solution and further modified with succinic anhydride in the microwave field for PLA reinforcement. A series of all-bionanocomposites containing unmodified and surface modified cellulose nanocrystals with CNC content in the range of 1–3 %_w.t. were obtained by melt blending and tested by XRD, SEM, DSC and DMA to investigate the effect of surface esterification of CNCs on the structure, morphology, dynamic mechanical properties of bionanocomposites, as well as phase transitions of PLA in the presence of cellulosic nanofiller. DMA investigations showed the… More > Graphic Abstract

Xing Zhou^1,*, Xin Zhang¹, Dong Wang¹, Changqing Fang^1,*, Wanqing Lei¹, Zhigang Huang², Yonghua Song¹, Xinyu He¹, Yingwei Huang¹

Journal of Renewable Materials, Vol.8, No.6, pp. 631-645, 2020, DOI:10.32604/jrm.2020.010176

Abstract Cellulose plays a key role in abundant organic natural materials meeting the increasing demand for green and biocompatible products. The highly crystalline nanoscale component of cellulose nanocrystals has recently attracted great attention due to the versatile performance as filler or matrix in producing functional materials. In this work, we prepared the waterborne polyurethane via a prepolymer process, and obtained cellulose and cellulose nanocrystals from waste paper via a facile acid hydrolysis process. After that, the cellulose nanocrystals were assembled into film and mixed with polyurethane to prepare flexible polyurethane/cellulose nanocrystals composite membrane with different soaking time. The correlation between the… More >

Xiaozheng Sun^*, Qiang He, Yu Yang

Journal of Renewable Materials, Vol.8, No.4, pp. 447-460, 2020, DOI:10.32604/jrm.2020.09671

Abstract Agricultural waste straw is the renewable resource with the highest annual yield in the world. In value-added applications of agricultural waste, dicarboxyl cellulose nanocrystals (DCCs) are prepared from rice, wheat, and corn straw by sequential periodate-chlorite oxidation. In this study, DCCs from rice, wheat, and corn straw were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometer, X-ray diffractometer (XRD), and thermal gravimetric analysis (TGA). The carboxyl content of the DCCs was also investigated. XRD results show that the crystallinity index decreased after sequential periodate-chlorite oxidation; however, the cellulose I structure was maintained. TEM results show that rod-shaped DCCs… More >

Mariia Stepanova¹, Ilia Averianov¹, Olga Solomakha¹, Natalia Zabolotnykh², Iosif Gofman¹, Mikhail Serdobintsev², Tatiana Vinogradova², Viktor Korzhikov-Vlakh^1,3, Evgenia Korzhikova-Vlakh^1,3,*

Journal of Renewable Materials, Vol.8, No.4, pp. 383-395, 2020, DOI:10.32604/jrm.2020.09206

Abstract The biocomposite films were prepared from poly(L-lactic acid) and cellulose nanocrystals. To improve interfacial compatibility of hydrophilic cellulose nanocrystals with hydrophobic matrix polymer as well as to provide the osteoconductive properties, cellulose was functionalized with poly(glutamic acid). The modified cellulose nanocrystals were better distributed and less aggregated within the matrix, which was testified by scanning electron, optical and polarized light microscopy. According to mechanical tests, composites filled with nanocrystals modified with PGlu demonstrated higher values of Young’s modulus, elongation at break and tensile strength. Incubation of composite materials in model buffer solutions for 30 weeks followed with staining of Ca²⁺… More >

Brody A. Frost, E. Johan Foster^*

Journal of Renewable Materials, Vol.8, No.2, pp. 187-203, 2020, DOI:10.32604/jrm.2020.07940

Abstract As the world's population exponentially grows, so does the need for the production of food, with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades. This rapid growth in food production results in an ever increasing amount of agricultural wastes, of which already occupies nearly 50% of the total landfill area. For example, is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually. This paper seeks to provide a method for isolating cellulose nanocrystals (CNCs) from spent coffee grounds, in order to recycle and utilize the… More >

Maud Chemin, Céline Moreau, Bernard Cathala, Ana Villares^*

Journal of Renewable Materials, Vol.8, No.1, pp. 29-43, 2020, DOI:10.32604/jrm.2020.07850

Abstract In this work, we studied the adsorption of modified cellulose nanocrystals onto solid surfaces by quartz crystal microbalance with dissipation monitoring (QCM-D). Cellulose nanocrystals obtained from tunicate (CNC) were modified at reducing end by amidation reactions. Two different functionalities were investigated: a polyamine dendrimer (CNC-NH₂), which interacts with gold surface by the amine groups; and a biotin moiety (CNC-Biot), which has a strong affinity for the protein streptavidin (SAV). QCM-D results revealed different adsorption behaviors between modified and unmodified CNCs. Hence, unmodified CNCs covered almost all the surface forming a rigid and flat layer whereas reducing end modified CNCs remained… More >