Samaneh Karimi | UPM - Universiti Putra Malaysia (original) (raw)

Papers by Samaneh Karimi

Research paper thumbnail of Kenaf bast cellulosic fibers hierarchy: A comprehensive approach from micro to nano

Carbohydrate Polymers, 2014

Cellulosic fibers from kenaf bast were isolated in three distinct stages. Initially raw kenaf bas... more Cellulosic fibers from kenaf bast were isolated in three distinct stages. Initially raw kenaf bast fibers were subjected to an alkali pulping process. Then pulped fibers undergone a bleaching process and finally both pulped and bleached fibers were separated into their constituent nanoscale cellulosic fibers by mechanical shearing. The influence of each treatment on the chemical composition of fibers was investigated. Moreover morphology, functional groups, crystallinity, and thermal behavior of fiber hierarchy at different stages of purification were studied using scanning and transmission electron microscopies, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Microscopy studies revealed that applied procedures successfully isolated nanoscale cellulosic fibers from both unbleached and bleached pulps. Chemical composition analysis and FTIR spectroscopy showed that lignin and hemicellulose were almost entirely removed by the applied treatments. XRD and TGA analyses demonstrated progressive enhancement of properties in fibers, hierarchically, in going from micro to nano scale. Interestingly no significant evolution was observed between obtained data of characterized ubnleached and bleached nanofibers.

Research paper thumbnail of Biodegradable starch-based composites: effect of micro and nanoreinforcements on composite properties

Journal of Materials Science, 2014

Thermoplastic starch (TPS) matrix was reinforced with various kenaf bast cellulose nanofiber load... more Thermoplastic starch (TPS) matrix was reinforced with various kenaf bast cellulose nanofiber loadings (0-10 wt%). Thin films were prepared by casting and evaporating the mixture of aqueous suspension of nanofibers (NFs), starch, and glycerol which underwent gelatinization process at the same time. Moreover, raw fibers (RFs) reinforced TPS films were prepared with the same contents and conditions. The effects of filler type and loading on different characteristics of prepared materials were studied using transmission and scanning electron microscopies, X-ray diffractometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and moisture absorption analysis. Obtained results showed a homogeneous dispersion of NFs within the TPS matrix and strong association between the filler and matrix. Moreover, addition of nanoreinforcements decreased the moisture sensitivity of the TPS film significantly. About 20 % decrease in moisture content at equilibrium was observed with addition of 10 wt% NFs while this value was only 5.7 % for the respective RFs reinforced film.

Research paper thumbnail of Isolation and Characterization of Cellulose Whiskers from Kenaf (Hibiscus cannabinus L.) Bast Fibers

Journal of Biomaterials and Nanobiotechnology, 2013

Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric aci... more Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydrochloric acid whiskers (HClW) morphology, functional groups, crystallinity, and thermal stability were characterized. The TEM images showed that the sulfuric acid and HCl whiskers have average diameters and length range of 3 nm and 100 -500 nm, respectively. The FTIR study indicated that during the conversion process, most of the hemicellulose and almost all the lignin were removed by the NaOH and subsequent bleaching treatments. The crystallinity of HCl whiskers was found to be higher (84%) than that of sulfuric acid whiskers (72%). Thermogravimetric analysis indicated that HCl whiskers had better thermal stability than the sulfuric acid ones. In addition, a two-stage decomposition behavior was revealed by TGA in the sulfuric acid whiskers because of incorporation of the sulfate group with the cellulose crystals.

Research paper thumbnail of A comparative study on characteristics of nanocellulose reinforced thermoplastic starch biofilms prepared with different techniques

Nordic Pulp & Paper Research Journal, 2014

Thermoplastic starch (TPS) and cellulose nanofibers (CNFs) obtained from kenaf bast were used to ... more Thermoplastic starch (TPS) and cellulose nanofibers (CNFs) obtained from kenaf bast were used to produce biofilms. CNFs were isolated by mechanical defibrillation of purified fibers. Three different casting techniques were chosen for material processing while material ratio, processing time and temperature were kept constant. The effects of casting technique on the morphology, mechanical properties and water sensitivity of the films were investigated by means of field emission scanning electron microscopy (FESEM), tensile and water uptake experiments. Obtained results indicated interesting differences in properties of biofilms and highlighted the importance of casting technique on the final performance of materials.

Research paper thumbnail of Effects of Wollastonite Nanofibers on Biological Durability of Poplar Wood (Populus nigra) against Trametes versicolor

Bioresources, 2013

The effect of impregnation with wollastonite nanofibers, a nontoxic mineral material, on the biol... more The effect of impregnation with wollastonite nanofibers, a nontoxic mineral material, on the biological durability of poplar wood (Populus nigra) against a white-rot fungus (Trametes versicolor) was studied. Wollastonite nano-suspension with a concentration of 6.3% was used; the size range of the nano-wollastonite (NW) was 30 to 110 nm. Results showed that decay exposed for 16 weeks in accordance with the standard DIN-52176 specifications resulted in a 47.5% mass loss in control specimens, while in the NW-impregnated specimens, only 3.6% mass loss occurred. Mechanical tests on separate sets of specimens impregnated with NW without exposure to the decay organism showed no significant difference in the mechanical properties. Thus, it can be concluded that impregnating poplar wood with NW as a preservative significantly increases the biological durability of poplar wood against deterioration by Trametes versicolor. Furthermore, it does not have negative effects on the mechanical properties in the impregnated poplar specimens.

Research paper thumbnail of Removal Of Colour From Pulp And Paper Mills Effluent Using Enzymatic Treatment And Advanced Oxidation Processes

MSc Dissertation, Jan 1, 2009

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Research paper thumbnail of The effect of combination enzymatic and advanced oxidation process treatments on the colour of pulp and paper mill effluent

Environmental Technology, Jan 1, 2010

Research paper thumbnail of Color remediation of chemimechanical pulping effluent using combination of enzymatic treatment and Fenton reaction

Desalination, Jan 1, 2009

This research investigated the efficiency of Advanced Oxidation Processes, Enzymatic treatment, a... more This research investigated the efficiency of Advanced Oxidation Processes, Enzymatic treatment, and combined enzymatic/AOPs sequences on color remediation of CMP pulp and paper mills effluent. Regarding enzymatic treatment two kinds of fungal enzymes; Laccase (EC: 1.10.3.2) from Terametes Versicolor and Versatile Peroxidase (EC: 1.11.1.7) from Bjerkandera adusta were chosen and applied. Also, the effect of external mediator on the enzyme based degradations was studied. It was found that both VP from Bjerkandera adusta and Laccase from Terametes versicolor decolorized the deep brown effluent to a clear light yellow solution. It has been found that, concomitant use of enzymes and photo-Fenton process produces a considerable effect on color remediation. The data analysis of sequence treatment indicated that, chemical treatment after the enzymatic stage (photo-Fenton as a post treatment unit) yield a better performance for the CMP effluent.

Research paper thumbnail of DISCOLORATION OF SODA PULPING EFFLUENT BY ADVANCED OXIDATION PROCESSES

Engineering e-Transaction, 2010

At the present time one of the pivotal concerns of science is water pollution control and wastewa... more At the present time one of the pivotal concerns of science is water pollution control and wastewater treatment. In this area treatment of colored-effluents remains a hardship. As a result, recently discoloration of industrial effluents is one of the major scientific interests. Present research focused on discoloration of pulp and paper mills effluent by means of chemical destructive methods. Obtained results related to the efficiency of two types of Advanced Oxidation Processes (AOPs); Fenton and Photo-Fenton processes, on discoloration of soda pulping effluent are presented. Findings clearly indicate that there is a significant difference between light absorbency of reference and Photo-Fenton treated samples. During the decolorization process, the color of the solution subsequently changed from dark to light brown and about 65% of the original color was removed from the soda effluent after 15 min during Photo-Fenton reactions.

Research paper thumbnail of Kenaf bast cellulosic fibers hierarchy: A comprehensive approach from micro to nano

Carbohydrate Polymers, 2014

Cellulosic fibers from kenaf bast were isolated in three distinct stages. Initially raw kenaf bas... more Cellulosic fibers from kenaf bast were isolated in three distinct stages. Initially raw kenaf bast fibers were subjected to an alkali pulping process. Then pulped fibers undergone a bleaching process and finally both pulped and bleached fibers were separated into their constituent nanoscale cellulosic fibers by mechanical shearing. The influence of each treatment on the chemical composition of fibers was investigated. Moreover morphology, functional groups, crystallinity, and thermal behavior of fiber hierarchy at different stages of purification were studied using scanning and transmission electron microscopies, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Microscopy studies revealed that applied procedures successfully isolated nanoscale cellulosic fibers from both unbleached and bleached pulps. Chemical composition analysis and FTIR spectroscopy showed that lignin and hemicellulose were almost entirely removed by the applied treatments. XRD and TGA analyses demonstrated progressive enhancement of properties in fibers, hierarchically, in going from micro to nano scale. Interestingly no significant evolution was observed between obtained data of characterized ubnleached and bleached nanofibers.

Research paper thumbnail of Biodegradable starch-based composites: effect of micro and nanoreinforcements on composite properties

Journal of Materials Science, 2014

Thermoplastic starch (TPS) matrix was reinforced with various kenaf bast cellulose nanofiber load... more Thermoplastic starch (TPS) matrix was reinforced with various kenaf bast cellulose nanofiber loadings (0-10 wt%). Thin films were prepared by casting and evaporating the mixture of aqueous suspension of nanofibers (NFs), starch, and glycerol which underwent gelatinization process at the same time. Moreover, raw fibers (RFs) reinforced TPS films were prepared with the same contents and conditions. The effects of filler type and loading on different characteristics of prepared materials were studied using transmission and scanning electron microscopies, X-ray diffractometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and moisture absorption analysis. Obtained results showed a homogeneous dispersion of NFs within the TPS matrix and strong association between the filler and matrix. Moreover, addition of nanoreinforcements decreased the moisture sensitivity of the TPS film significantly. About 20 % decrease in moisture content at equilibrium was observed with addition of 10 wt% NFs while this value was only 5.7 % for the respective RFs reinforced film.

Research paper thumbnail of Isolation and Characterization of Cellulose Whiskers from Kenaf (Hibiscus cannabinus L.) Bast Fibers

Journal of Biomaterials and Nanobiotechnology, 2013

Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric aci... more Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydrochloric acid whiskers (HClW) morphology, functional groups, crystallinity, and thermal stability were characterized. The TEM images showed that the sulfuric acid and HCl whiskers have average diameters and length range of 3 nm and 100 -500 nm, respectively. The FTIR study indicated that during the conversion process, most of the hemicellulose and almost all the lignin were removed by the NaOH and subsequent bleaching treatments. The crystallinity of HCl whiskers was found to be higher (84%) than that of sulfuric acid whiskers (72%). Thermogravimetric analysis indicated that HCl whiskers had better thermal stability than the sulfuric acid ones. In addition, a two-stage decomposition behavior was revealed by TGA in the sulfuric acid whiskers because of incorporation of the sulfate group with the cellulose crystals.

Research paper thumbnail of A comparative study on characteristics of nanocellulose reinforced thermoplastic starch biofilms prepared with different techniques

Nordic Pulp & Paper Research Journal, 2014

Thermoplastic starch (TPS) and cellulose nanofibers (CNFs) obtained from kenaf bast were used to ... more Thermoplastic starch (TPS) and cellulose nanofibers (CNFs) obtained from kenaf bast were used to produce biofilms. CNFs were isolated by mechanical defibrillation of purified fibers. Three different casting techniques were chosen for material processing while material ratio, processing time and temperature were kept constant. The effects of casting technique on the morphology, mechanical properties and water sensitivity of the films were investigated by means of field emission scanning electron microscopy (FESEM), tensile and water uptake experiments. Obtained results indicated interesting differences in properties of biofilms and highlighted the importance of casting technique on the final performance of materials.

Research paper thumbnail of Effects of Wollastonite Nanofibers on Biological Durability of Poplar Wood (Populus nigra) against Trametes versicolor

Bioresources, 2013

The effect of impregnation with wollastonite nanofibers, a nontoxic mineral material, on the biol... more The effect of impregnation with wollastonite nanofibers, a nontoxic mineral material, on the biological durability of poplar wood (Populus nigra) against a white-rot fungus (Trametes versicolor) was studied. Wollastonite nano-suspension with a concentration of 6.3% was used; the size range of the nano-wollastonite (NW) was 30 to 110 nm. Results showed that decay exposed for 16 weeks in accordance with the standard DIN-52176 specifications resulted in a 47.5% mass loss in control specimens, while in the NW-impregnated specimens, only 3.6% mass loss occurred. Mechanical tests on separate sets of specimens impregnated with NW without exposure to the decay organism showed no significant difference in the mechanical properties. Thus, it can be concluded that impregnating poplar wood with NW as a preservative significantly increases the biological durability of poplar wood against deterioration by Trametes versicolor. Furthermore, it does not have negative effects on the mechanical properties in the impregnated poplar specimens.

Research paper thumbnail of Removal Of Colour From Pulp And Paper Mills Effluent Using Enzymatic Treatment And Advanced Oxidation Processes

MSc Dissertation, Jan 1, 2009

of

Research paper thumbnail of The effect of combination enzymatic and advanced oxidation process treatments on the colour of pulp and paper mill effluent

Environmental Technology, Jan 1, 2010

Research paper thumbnail of Color remediation of chemimechanical pulping effluent using combination of enzymatic treatment and Fenton reaction

Desalination, Jan 1, 2009

This research investigated the efficiency of Advanced Oxidation Processes, Enzymatic treatment, a... more This research investigated the efficiency of Advanced Oxidation Processes, Enzymatic treatment, and combined enzymatic/AOPs sequences on color remediation of CMP pulp and paper mills effluent. Regarding enzymatic treatment two kinds of fungal enzymes; Laccase (EC: 1.10.3.2) from Terametes Versicolor and Versatile Peroxidase (EC: 1.11.1.7) from Bjerkandera adusta were chosen and applied. Also, the effect of external mediator on the enzyme based degradations was studied. It was found that both VP from Bjerkandera adusta and Laccase from Terametes versicolor decolorized the deep brown effluent to a clear light yellow solution. It has been found that, concomitant use of enzymes and photo-Fenton process produces a considerable effect on color remediation. The data analysis of sequence treatment indicated that, chemical treatment after the enzymatic stage (photo-Fenton as a post treatment unit) yield a better performance for the CMP effluent.

Research paper thumbnail of DISCOLORATION OF SODA PULPING EFFLUENT BY ADVANCED OXIDATION PROCESSES

Engineering e-Transaction, 2010

At the present time one of the pivotal concerns of science is water pollution control and wastewa... more At the present time one of the pivotal concerns of science is water pollution control and wastewater treatment. In this area treatment of colored-effluents remains a hardship. As a result, recently discoloration of industrial effluents is one of the major scientific interests. Present research focused on discoloration of pulp and paper mills effluent by means of chemical destructive methods. Obtained results related to the efficiency of two types of Advanced Oxidation Processes (AOPs); Fenton and Photo-Fenton processes, on discoloration of soda pulping effluent are presented. Findings clearly indicate that there is a significant difference between light absorbency of reference and Photo-Fenton treated samples. During the decolorization process, the color of the solution subsequently changed from dark to light brown and about 65% of the original color was removed from the soda effluent after 15 min during Photo-Fenton reactions.