Mingzhe Jiang¹, S. Nicole DeMass¹, D. Ross Economy², Thomas Shackleton¹, Christopher L. Kitchens^1*

Journal of Renewable Materials, Vol.4, No.5, pp. 377-387, 2016, DOI:10.7569/JRM.2016.634131

Abstract Spin coating was used to cast a uniform film of cellulose nanocrystals with low surface roughness and variable thickness as a function of operational parameters that include rotational speed and dispense suspension concentration. The film thickness was controllable from 40 nm up to 1 μm with surface roughness an order of magnitude less than blade-coating methods. The degree of radial orientation was qualitatively assessed and shown to be variable with processing parameters. Under specific processing conditions, the formation of striation patterns was observed and associated with film drying instability. The striation patterns are periodic in nature where the wavelength and… More >

Jose Luis Orellana, Michael Mauhar, Christopher L. Kitchens^*

Journal of Renewable Materials, Vol.4, No.5, pp. 340-350, 2016, DOI:10.7569/JRM.2016.634126

Abstract Polylactic acid (PLA) is one of the most widely used biodegradable polymers due to the ability to synthesize it economically at industrial scale and its favorable properties for many consumer products. However, the rigid nature of PLA is not desirable for specific applications, requiring the incorporation of effective bioderived additives in order to enhance the PLA toughness and broaden applications. In this work, PLA was modified by graft polymerization of polyacrylic acid (PLA-g-PAA) to increase the hydrophilicity to promote compatibilization of cellulose nanocrystals (CNCs) or high molecular polyethylene glycol (PEG). CNCs were found to act as a nucleating agent for… More >

Craig Clemons

Journal of Renewable Materials, Vol.4, No.5, pp. 327-339, 2016, DOI:10.7569/JRM.2016.634112

Abstract Continuous fibers are commonly manufactured for a wide variety of uses such as filters, textiles, and composites. For example, most fibrous reinforcements (e.g., carbon fiber, glass fiber) for advanced composites are continuous fibers or yarns, fabrics, and preforms made from them. This allows broad flexibility in design and manufacturing approaches by controlling fiber orientation and architecture. However, there has been growing interest in preparing continuous fibers from biobased materials such as plants. Of particular recent interest are nanocelluloses, which are projected to be less expensive than many other nanomaterials and have the potential to be produced in large volumes. They… More >

Nicole M. Stark

Journal of Renewable Materials, Vol.4, No.5, pp. 313-326, 2016, DOI:10.7569/JRM.2016.634115

Abstract Performance requirements for packaging films may include barrier properties, transparency, flexibility, and tensile strength. Conventional packaging materials, such as plastic films and laminates, are typically made from petroleum-based polymers. Currently, there is a drive to develop sustainable packaging materials. These alternative materials must be able to be manufactured economically and on a commercial scale, exhibit barrier properties and transparency, and provide adequate mechanical performance. As a biobased, renewable material, cellulose nanomaterials (CNs) are ideally suited to be used in sustainable packaging applications. CNs include cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) and each can provide benefit to packaging films. Manufactured… More >

Ronald Sabo^1*, Aleksey Yermakov², Chiu Tai Law³, Rani Elhajjar⁴

Journal of Renewable Materials, Vol.4, No.5, pp. 297-312, 2016, DOI:10.7569/JRM.2016.634114

Abstract Cellulose nanomaterials have a number of interesting and unique properties that make them well-suited for use in electronics applications such as energy harvesting devices, actuators and sensors. Cellulose nanofibrils and nanocrystals have good mechanical properties, high transparency, and low coefficient of thermal expansion, among other properties that facilitate both active and inactive roles in electronics and related devices. For example, these nanomaterials have been demonstrated to operate as substrates for flexible electronics and displays, to improve the efficiency of photovoltaics, to work as a component of magnetostrictive composites and to act as a suitable lithium ion battery separator membrane. A… More >

F. Luzi, E. Fortunati^*, D. Puglia, R. Petrucci, J.M. Kenny, L. Torre

Journal of Renewable Materials, Vol.4, No.3, pp. 190-198, 2016, DOI:10.7569/JRM.2015.634134

Abstract In this research, the revalorization of Posidonia oceanica leaf sea waste was studied and the acid hydrolysis processing times were modulated in order to optimize the extraction of cellulose nanocrystals (CNCs). The obtained CNCs were deeply investigated. A two-step treatment was applied to extract cellulose nanocrystals from Posidonia oceanica leaves. First, a chemical treatment leads to the removal of lignin and production of holocellulose, while the second chemical process of acid hydrolysis allows the obtainment of cellulose nanocrystals in aqueous suspension. The unbleached and bleached leaves and cellulose nanocrystals were characterized by using thermogravimetric analysis, infrared spectroscopy and morphological investigation;… More >

Donggang Li^1,2, Alexandra Levesque², Qiang Wang^1,3,2, Agnieszka Franczak², Chun Wu¹, Jean-Paul Chopart², Jicheng He¹

CMC-Computers, Materials & Continua, Vol.30, No.3, pp. 207-218, 2012, DOI:10.3970/cmc.2012.030.207

Abstract Co/Ni bilayered films were prepared on ITO glass by electrodeposition assisted with a magnetic field up to 0.5T aligned parallel to the electrode surface. The effect of a high magnetic field annealing up to 12T on morphology and microstructure of the post-deposited films was investigated by field emission scanning electronic microscopy (FE-SEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). Grain shape and grain boundary in the Co/Ni morphology were modified dramatically when the high magnetic field was applied during the annealing process. Magnetic anisotropy appeared in the films due to the preferential orientation of fcc-CoNi alloy in comparison with… More >

Wen-Jay Lee^1,*, Yu-Chien Lo², Anchen Yang³, Kuanpeng Chen³, Nan-Yow Chen³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 293-304, 2019, DOI:10.32604/cmes.2019.06620

Abstract Different thickness of amorphous/nanocrystalline multi-layered structure can be used to modulate the strength and ductility of the composite materials. In this work, molecular dynamics simulations were conducted to study the thickness effect of nanocrystalline layer on mechanical properties and deformation behavior of the Cu₆₄Zr₃₆/Cu multi-layer structure. The stress-strain relationship, local stress, local strain, and deformation mechanism are investigated. The results reveal that the change of thickness of the crystalline layer significantly affects the mechanical properties and deformation behavior. As the strain at the elastic region, the amorphous Cu₆₄Zr₃₆ layer dominates the mechanical behavior, leading the fact that Young’s modulus, first… More >

Marcin Maździarz¹, Marcin Gajewski²

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.2, pp. 123-150, 2015, DOI:10.3970/cmes.2015.105.123

Abstract In this paper, the choice and parametrisation of finite deformation polyconvex isotropic hyperelastic models to describe the behaviour of a class of defect-free monocrystalline metal materials at the molecular level is examined. The article discusses some physical, mathematical and numerical demands which in our opinion should be fulfilled by elasticity models to be useful. A set of molecular numerical tests for aluminium and tungsten providing data for the fitting of a hyperelastic model was performed, and an algorithm for parametrisation is discussed. The proposed models with optimised parameters are superior to those used in non-linear mechanics of crystals. More >

Hongtao Wang^1,2, Haitao Wang², Lie Jin², Zhenhan Yao³

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.6, pp. 529-552, 2013, DOI:10.3970/cmes.2013.094.529

Abstract Since only the boundary of the analyzed domain needs to be discretized, the boundary element method (BEM) inherently has the advantages of solving crack problems. In this paper, a micromechanics BEM scheme is applied to determine the effective elastic moduli of three-dimensional (3-D) solids containing a large number of parallel or randomly oriented microcracks. The 3-D analyses accelerated by the fast multipole method were carried out to investigate the relations between the effective elastic moduli and the microcrack density parameter. Numerical examples show that the results agree well with the available analytical solution and known micromechanics models. From the numerical… More >