مهدی جنوبی

Considering the large volume of waste banknotes and the high costs of disposal as well as the resulting environmental pollution, the possibility of converting these wastes into products such as cellulose acetate polymers, which are economically viable, and also their production process with the least environmental pollution It is very important to be accompanied. In this article, in order to obtain cellulose acetate after dyeing the banknotes, the acetylation process was carried out using acetic acid as a solvent, sulfuric acid as a catalyst, and acetic anhydride. The percentage efficiency of acetylation increased with increasing reaction time and temperature, and the maximum efficiency was obtained at 55 °C. The concentration of acetic anhydride and sulfuric acid as a catalyst changed the substitution degree of cellulose acetate polymer. Scanning electron microscope images showed that the diameter of cellulose acetate fibers decreased compared to pure cellulose (waste banknote). The results of the Fourier transform infrared spectrometer showed that practically a significant amount of hydroxyl groups were replaced by acetate groups. The X-ray diffraction patterns of the bleached banknote sample changed after the acetylation process, which is evident in the reduction of the peak at position 23 of the sample before and after acetylation

The lack of wood resources on the one hand and the increase in the demand for wood products on the other hand have caused the excessive harvesting of wood and the shortage of wood raw materials. Therefore, alternative materials should be used to solve this problem. But, in addition to providing raw materials, alternative materials must be approved from the economic point of view and the mechanical properties of the boards. Since CZ100 is a crystalline and homogeneous mineral, it is cheap and readily available. It also has high strength, stability, and mechanical resistance. Therefore, the aim of this research is the effect of CZ100 additive on the physical and mechanical properties of particleboard. For this purpose, boards were made with CZ100 additive in proportions (0, 2, 4, 6, 8, and 10%). Then, the mechanical and physical properties of particleboard made with CZ100 additive were measured. The results showed that the mechanical properties of particleboard increased with the addition of the CZ100 additive by up to 6 wt%, and with the addition of the additive, water absorption and thickness shrinkage (2 and 24 hours) decreased significantly. In general, according to the obtained results, the additive CZ100 has a high potential to improve the physical and mechanical properties of particleboard and also due to its low price compared to wood, its use reduces the costs of preparing raw materials.

Cellulose is the most abundant natural fiber on earth which considered a renewable source for obtaining environmentally friendly products. The extraction of pure cellulose fibers from lignocellulosic materials requires the application of special extraction methods. However, several challenges arise during cellulose extraction processes. To overcome these problems and make it easier to layer the cell wall and release the cellulose micro and nano structures, in many recent researches, various pretreatment methods are used considering their application. Pretreatment methods can change the structural organization, crystallinity, and polymorphism of cellulose. In addition, it can change the various properties of pretreated raw materials. Therefore, it is very important to know the types of pretreatment methods. Therefore, in the present study, by using the content analysis method and reviewing the most important related works, the types of pretreatment methods necessary for the extraction of cellulose were reviewed and categorized. The results of the present work have been presented for the researchers active in the field of cellulose/polymer micro and nano composites, who need to extract a variety of micro or nano cellulosic structures to advance their research.

Nowadays, the utilization of lignocellulosic residues in the production of engineered wood products is promising for sustainable development... The purpose of this research is to investigate the properties of LSL (Laminated strand lumber) and hybrid based glulam using date biomass in the presence of two types of adhesives, i.e. epoxy and polyvinyl acetate. For this purpose, LSL was made using date palm rachis and phenol-formaldehyde resin. In order to evaluate the performance of glulam beams, physical and mechanical properties were considered. The physical and mechanical performance of glulams in the presence of epoxy adhesive was better than polyvinyl acetate adhesive. The LSL impact resistance was 6/9 J/cm.Hybrid glulams provided higher mechanical resistance despite lower density. The highest amount of flexural strength and modulus of elasticity with values of 37/3 and 7856 MPa, respectively, was related to Hybrid glulam with epoxy glue. The highest compressive strength was related to the combined glulam made in the presence of polyvinyl acetate adhesive (2/27 MPa); However, no significant difference was observed between the compressive strength of glulam beams.

Medium density fiberboard is one of the most important products in building and interior design. In such applications, reinforcement of mechanical properties and improving dimensional stability is essential. In this research, the effect of zeolite compounds with the mixtures of 1, 2.5 and 5 % (on the basis of fiber dry weight) and three positions of mixing (mix with fibers, mix with resin and mix with glued fibers) on the physical and mechanical properties of medium density fiberboard was investigated. Physical tests (water absorption and thickness swelling) and mechanical tests (internal bonding and bending strength) were performed on the samples. According to the results, the use of zeolite compounds in all levels and mix stages except for mix with resin, improved dimensional stability (water absorption and thickness swelling) and reinforcement of mechanical properties. In the meantime, the optimum physical and mechanical properties were achieved by using zeolite compounds at the levels of 2.5 and 5 % in mixed with glued fibers.

Wastewater treatment plants are known as an important source of microplastics. Though a major proportion of microplastics are removed in wastewater treatment plants, the effluent of plants contain a significant amount of microplastic particles which eventually release into the environment. Until now there is no investigation on the role of wastewater treatment plants on the release of microplastics in Tehran. This study aims to assess the discharge amount of microplastic particles from wastewater treatment plant in district 22 of Tehran. Sampling was conducted from the influent and effluent of the plant with grab method and sieving through 300, 105 and 25 µm stainless still filters.  Retained samples were treated to remove organic and inorganic materials. Then particles were detected, counted and analyzed under microscope (*10). Results indicate that treatment process has a significant impact on microplastic particles removal. After the treatment process, the average of 2.15 MP/liter were found in the effluent. Larger particles were removed effectively (at the size of ≥300 and 105-300 µm) and smaller particles (25-105 µm) indicated a higher abundance. Among the detected particles fibers had the highest abundance and then fragment were at the second order. This finding indicates that waste water treatment plants can act as a source for microplastic pollution in the urban environment.

This study aimed to investigate the biodegradability behavior and thermal properties of polycaprolactone / polylactic acid / nanocrystalline cellulose nanocomposites. Polycaprolactone and polylactic acid were dissolved in chloroform in ratios of 100/0, 95/5, 90/10, and 80/20%, and cellulose nanocrystals were added to the compounds at levels of 0, 0.5, 1, and 3%. Nanocomposites were prepared by solvent casting method. Then, their biodegradability behavior in the soil environment was investigated. The thermal properties of nanocomposites were investigated by thermogravimetric analysis and differential scanning calorimetry tests. Field emission scanning electron microscopy was also used for the microscopic study of nanocomposites. The results showed that with increasing cellulose nanocrystals to 1%, the mass loss of nanocomposites increased, but adding 3% of it led to a decrease in the mass loss of nanocomposites. With the increase of polylactic acid, up to 10%, the mass loss of the composites decreased, but the addition of 20% of it led to a decrease in the mass loss of the composites. The addition of cellulose nanocrystals to polycaprolactone increased its thermal resistance, but the addition of polylactic acid reduced this resistance. The results of scanning electron microscopy confirmed the degradation of nanocomposites in the soil.

This study aims to use zeolite as a retarder of particleboards from sugarcane pulp (bagasse). In this study, mechanical properties, physical properties, fire resistance and CIE L * a * b * colorimetric test were investigated. The results of this study showed that the use of zeolite led to an increase in flexural strength, modulus of elasticity and impact resistance of the resulting particleboards. However, the internal adhesion of the resulting particleboard decreased. In addition, the use of zeolite as a flame retardant increased fire resistance. The results of physical properties also showed that zeolite reduced water absorption and thickness swelling in 2 hours of immersion. While water uptake and thickness swelling increased during 24 hours of immersion. The results showed that zeolite caused color change with increasing Δl and finally increased the whiteness and brightness of the surface of the samples. Zeolite reduced the combustion parameters, reduced the mass due to burn and the amount of carbonized surface and significantly increased the ignition time while drastically reduces flame retention and weight loss. In general, according to the measured parameters, the addition of zeolite can be considered as a slowing treatment.

In this study, the effect of using maleic anhydride and oxidizer (dicumyl peroxide) in improving the properties of composites made of polypropylene and cellulose nanocrystal was investigated. Then, the mechanical, and morphological properties of these composite products were explored. Tensile strength increased with increasing cellulose nanocrystal, but it decreased slightly while 5% of cellulose nanocrystal were added. Due to the addition of maleic anhydride and oxidizer, the mechanical properties of the composite product were reduced which was not expected. Analysis of the contact angle of the samples also showed a decrease in wettability behavior due to increased use of nanocrystalline cellulose as well as maleic anhydride and dicumyl peroxide.

The aim of this study was to investigate the mechanical, dynamic-mechanical and morphological properties of poly-capro-lactone/poly-lactic acid/cellulose nano crystal three-component nanocomposites. For this purpose, the nanocomposites were manufactured using casting solution method. Then, mechanical tests including tensile strength, tensile modulus and elongation at break and dynamic-mechanical test including storage modulus, loss modulus and loss factor were performed on nanocomposites. Field emission scanning electron microscopy was used to study the morphology of the nanocomposites and infrared spectroscopy was used to investigate possible reactions. The result showed that with increasing cellulose nano crystal and poly-lactic acid, the mechanical and dynamic-mechanical properties were improved. Field emission scanning electron microscopy confirmed the presence of nanoparticles in the nanocomposites and the results of infrared spectroscopy confirmed the hydrogen reaction between the hydroxyl groups of cellulose nano crystal with the carbonyl groups of poly-capro-lactone and poly-lactic acid, as well as the hydroxyl groups and carbonyl groups of both polymers with each other.

Pollution from airborne particles is one of the most important threats to human and environmental health in the world. Today, industrial air filters use synthetic polymers based on oil and chemicals, these materials are incompatible with the environment and lead to secondary pollution. Therefore, the development of the use of new materials in the fabrication of air filters, which is not only environmentally friendly but also renewable, is a vital need. For this reason, in recent years, many researches and studies have been done to replace cellulose nanofiber (CNF) with synthetic fibers such as glass nanofibers, activated carbon, and plastic polymersnanofibers in the manufacture of air filters. CNF has many advantages such as biodegradability, cheapness, low density, and network structure that can compete with synthetic nanofibers. Therefore, this review study aims to investigate the general use of CNF for the adsorption of particulate matter (PM) and carbon dioxide (CO2) in the air. The results showed that CNF increase the adsorption efficiency of CO2 and PM due to the presence of active hydroxyl groups on the surface as well as high specific surface area. In addition, the nanofilters made of CNF have a lower pressure drop than filters on the market due to their small pore diameter.

The purpose of this study was to fabricate nano filters to adsorb particulate matters less than 2.5 μm using phthalimide modified cellulose nanofibers. Modification of cellulose nanoparticles with phthalimide was performed on acetic acid with the cellulose to phthalimide nanofiber ratios of 1:0, 1:0.5, 1:1 and 1:1.5 wt%. Modified cellulose nanofibers were evaluated by various techniques including SEM and ZP (zeta potential). Finally, cellulose nanofibers, both pure and unmodified, were evaluated for the adsorption of particulate matters and compared with the control filter (HEPA). SEM analysis showed no significant change in the size and structure of cellulose nanofibers due to modification, but with increasing phthalimide content, the specific surface area increased while porosity and pore diameter decreased. The results of the effect of temperature on the adsorption of particulate matters showed that the highest adsorption of particulate matters less than 0.1 μm was related to 1.5% phthalimide-modified cellulose nanofibers and 65°C (76%). However, the adsorption of particulate matter was above 0.3 μm for all purified and modified cellulose nanofibers.

One application of hydrogels is to use them as dressings (wounds and burns). Biocompatibility and cytotoxicity are of particular significance for hydrogels used in the medical field. Cellulosic materials can load and relief drugs at temperatures or pH levels of the body as a result of contrary processes such as diffusion. The aim of this study was to investigate the mechanism of release of silver nitrate in nano-cellulose-based biodegradable hydrogel film for burn repair. To prepare a hydrogel in the form of film, cellulose nanofibers and hydroxyethyl cellulose were used with the weight ratio (3:1), and also, the citric acid was used as a crosslinker in different amounts of 10 and 20 wt% matrix. Later on, the loading silver nitrate as a disinfectant drug into selected hydrogels was performed. Drug release results illustrated that there was a direct relationship between absorption rate and drug concentration. In the initial times of the testing, 70 to 90% of the drug release was detected and then for 24 h, the drug was gradually released from the hydrogel. Investigation of modeling drug-releasing selected kinetic diffusion as the dominant mechanism in drug delivery. MTT non-toxicity test displayed high efficacy of nanocellulose cationization and confirmed the non-toxicity of biocompatible hydrogels. It can be concluded that biodegradable nanocellulose based hydrogel containing silver nitrate can be used as an appropriate and relevant product for burn repair.

Acetate cellulose was used as cigarette filter, whose main function is to cool and purify the cigarette smoke. Nano cellulose as a sustainable bio material seems to have high potential as it is most common bio polymer in nature and is already available in micrometers to nanometers. In this research, cigarette filters were made of cellulose nano fibers with a concentration of 1%, 2% and 3% as well as mixture of each with 5% activated carbon. For this aim, the freezing of nano cellulose suspension in liquid nitrogen was used. After placing the filters in cigarettes, the samples were tested by the smoking machine and the carbon monoxide produced by burning cigarettes was directly measured by the machine and the amount of nicotine and tar were determined by gas chromatography test. The results of carbon monoxide and tar test showed that the use of filters made with cellulose nanofibers and activated carbon in comparison with acetate cellulose filters could significantly reduce these toxic and harmful substances (59.6% and 77% respectively) however, nicotine of tested samples did not show a significant difference by control sample.

The purpose of this study is to fabricate air filters with various concentrations of cellulose nanofibres (CNFs) in order to evaluate its ability in the process of adsorbing (to adsorb) carbon dioxide (CO2). In this study, we make use of freezing drying method for making filters with three different concentrations (1, 1.5 and 2%). SEM results show that increasing the concentration of CNFs increase the surface area but decreases the porosity and pore diameter. The results are also confirmed by the BET test. Also, mechanical properties and CO2 adsorption test were investigated. The results show that decreasing the concentration of CNFs decreases mechanical strength and carbon dioxide adsorption such that the minimum mechanical strength and adsorption of CO2 were for unmodified CNFs with 1% concentration and the highest adsorption of CO2 is associated with the modified 2% concentration CNFs.

chitin and chitosan, as the most abundant amino-polysaccharide in nature, have characteristics such as biocompatibility, low toxicity, and biodegradability. These unique specifications have resulted in chitin and chitosan attracting a lot of attention because of the high potential for producing valuable products. Chitosan has many uses in the agricultural industry and wood preservation, such as pesticides and insecticides, as well as in biomedical applications, including the use in the pharmaceutical industry as a drug release, and can also be used as drug carriers. The purpose of this article is to extract highly purified chitosan with high de-acetylation degree from shrimp shells.

In this study, the extraction and characterization of chitosan from the shrimp shell (Litopenaeus vannamei) was investigated. For this purpose, chitosan was extracted by chemical method including mineralization (with 4% HCl concentration), protein degradation (with 4% NaOH concentration), and deacetylation (with 60% NaOH concentration). Also, nano-chitosan was prepared by ionic gelation method. A series of parameters were studied, which included the degree of deacetylation, molecular weight, pH and solubility. Also, FTIR spectroscopy, FESEM scanning electron microscopy, Zeta potential, X-ray diffraction spectroscopy (EDX) and X-ray diffraction (XRD) were used.

The results of FTIR test on chitin and chitosan extracted from shrimp shell showed that the removal of protein and mineral materials was appropriate with the use of hydrochloric acid, sodium hydroxide. The high degree of deacetylation of chitosan in this study (87%) had a significant effect on the proper solubility and low viscosity of chitosan. The solubility of chitosan in acetic acid was 86%. The molecular weight of the chitosan extracted was 110 kDa. With this molecular weight, chitosan can be used well in the pharmaceutical industry. According to chitosan XRD patterns in previous studies, the peaks obtained in XRD patterns in this study confirmed the semi-crystalline structure of chitosan. Due to the change in the level of chitosan seen in FESEM images, it can be due to the purification of chitosan. The FESEM test confirms nano-chitosan with diameter range of 100 to 150 nm.

From the results of this study, it can be concluded that using the chitosan extraction method in this research, highly purified chitosan with high de-acetylation degree can be obtained. With increasing degree of deacetylation, the solubility of chitosan has increased, and this degree of deacetylation has had a significant effect on improving molecular weight (Low molecular weight). As a result of the study of the role of solubility of chitosan in the vicinity of acetic acid, it becomes obvious that the solubility of the chitosan and the size of the nano-chitosan particles depend on the solution pH. The produced chitosan can be used in wide variety of application mainly in pharmaceutical industry.

This study aimed to fabricate the bilayer scaffold containing nanocellulose/poly (vinyl) alcohol (CNF/PVA) to evaluate its potential use as a mimic for skin tissue engineering. A continuous process of layer addition with two different concentrations of polymers by freeze-drying technique was used. FE-SEM analysis indicated that the obtained scaffolds had interconnected porosity and pore size, which increased in lower concentration of polymers. The scaffolds were also characterized by water uptake, mechanical properties and MTT assay. Lower concentration of polymers increased water uptake and decreased mechanical strength. The MTT assay results showed that these nanofibrous scaffolds meet the requirement as a biodegradable material for skin repair.

The applications of renewable nanomaterial’s, such as cellulose nanofibers (CNFs), have recently been of great interest due to their unique properties, including high surface area, high aspect ratio, biodegradable, easy access and reactive hydroxyl groups on the surface. The purpose of this study was to fabricate refined air nano filters using phthalimide- modified CNFs. Because phthalimide contains amine groups that are needed to adsorb carbon dioxide. In this study, a freeze drying method was used for direct removal of water from pure CNFs gel and phthalimide -modified. Also, the properties of pure CNFs aerogels and phthalimide-modified (containing amine groups) were investigated to adsorption carbon dioxide. Modification of CNFs with phthalimide in 4% (v/v) acetic acid, with ratios of CNFs to phthalimide 1: 0, 1: 0.5, 1: 1 and 1: 1.5 wt %. Chemical properties and morphology of modified CNFs were investigated using various techniques including SEM, FTIR-ATR, XRD and TGA. Based on the results, the SEM test did not show any change in the size and structure of the modified CNFs. The presence of phthalimide was confirmed by the creation of new pitches NH2, C-N and ester 〖COO〗^- on modified CNFs using the ATR-FTIR spectroscopy test. Also, the results of TGA indicated that increasing the amount of phthalimide reduces the thermal stability, indicating the reactivity of the functional groups of phthalimide with CNFs. In addition, the highest carbon dioxide adsorption of 1.5% phthalimide was about 50%.

This study was focused on the preparation of an environmentally friendly nanocellulose based hydrogel in the form of pads. Hydrogels are hydrophilic three dimensional network with crosslinks, swells in water but don’t dissolve. In this research nanofibrillated cellulose and Hydroxyethyl cellulose with different ratio (1:1, 2:1, 3:1) were used to make hydrogel. Also, citric acid which has a significant advantage over other crosslinking agents in terms of toxicity and price, has been used in different amounts of 10% and 20% by weight to crosslink. In order to find optimal hydrogel preparation conditions, FTIR analysis, FESEM, time dependent swelling measurement and evaluating the thermal and rheological properties were performed. Samples with a lower ratio of nanocellulose to hydroxyethyl cellulose were found to be inappropriate due to the loss of their apparent integrity in the swelling measurement. According to FTIR results, cross-linking were performed only in samples with the highest ratio of nanocellulose to hydroxyethyl cellulose in different amounts of citric acid. Therefore, the hydrogels' characteristics were mainly influenced by the ratio of nanocellulose to hydroxyethyl cellulose and the amount of citric acid had less effect on these properties. These two successful final samples showed acceptable properties in other evaluated properties and led to the selection of optimal reactive ratios for the preparation of hydrogels for use in various industries, including the pharmaceutical industry.

Impregnation of wood with different monomers and their conversion to the un-leachable reacted polymers inside the wood causes a new product which is called wood polymer. The furan compounds such as Furfuryl alcohol (FA) is commercially used for wood modification, producing then wood polymer. Wood is impregnated with FA, convert to the polyFA by heating. Furfural which is in fact the primary raw material in the manufacture of FA is extensively manufactured in Iran from residues of sugar cane. Furfural could not be easily polymerized alone like FA; but it is an aldehyde which can react with urea to make polymer network. In this study, the possibility of furfural/urea polymer along with acidic catalyzer (maleic anhydride) was evaluated for the improvement of physico-mechanical properties of birch wood. Birch wood (Betula sp.) imported from Russia was used for experiments. With a double treatment procedure Furfural+Urea/Maleic anhydride was impregnated into the wood according to a 2 steps vacuum/pressure technology: (1) diluted furfural in water and methanol, followed by (2) Urea/Maleic anhydride aqueous solution. For making comparison between the results, a commercial formulation based on the FA was also used as a reference. The mixes impregnated into the wood were polymerized by heating. Then, different physico-mechanical properties of wood samples were measured according to the standard guidelines of ISO 13061 series. The proportion of Furfural+Urea/Maleic anhydride was appropriately selected, and approximately 60 to 80% were converted to the polymer. The leaching rate of the products once polymerized within the treated wood was around 4% which is comparable to the results of commercial formulation based on FA. The weight percentage gain (WPG) of the wood samples varied between 27 to 57% depending on the furfural concentration in the treatment solutions. Despite the bulking effect, the density of samples after treatment increased significantly. The water absorption during samples soaking in the water is clearly linked with the WPG, and decreases with the increase of WPG. The volumetric swelling of the samples treated with the combination of furfural+urea/maleic anhydride also follows the same trend. However, the lowest volumetric swelling was obtained with the treatment with FA. The mechanical resistance evaluation showed that wood treatment by furfural +urea/maleic anhydride reduced the hardness and the impact bending of wood, while static strength such as modulus of rupture, modulus of elasticity, and compression parallel to the grain increased. The treatment with FA also reduced the resistance of wood against impact bending. Wood treatment with the complex of furfural+urea/maleic anhydride, especially at high WPG levels, has a good potential for improving most wood properties. The high acidity of furfural based solutions is one of the issues requiring additional studies. If the alkaline pH is used, the curing of the resin will be disturbed and the leaching rate will increase. On the other hand, acidic pH also has a negative impact on wood properties.

The aim of this study was to determine stress carrying capacity of doweled corner joints in wood members made with modified resin (polyvinyl acetate) and its comparison with unmodified ones. Joint members were out of European silver Fir (Abies alba) and dowels were made from Beech and poplar woods as variables in this study. Diameter of dowel had three levels in size, namely 6, 8 and 10 mm. The experimental joints were tested under diagonal compression loads. Results have shown that stress carrying capacity of tested joints made with modified glue is more than unmodified ones. Maximum stress capacity was observed in the joints of beech which with 10 mm in diameter dowels. Based on the results, the highest strength was belonging to those joints made with beech wood glued with modified resin containing 10 mm dowel. Furthermore, the lowest strength was belonging to poplar joints made with unmodified resins and 6 mm dowels. The improvement can be due to increased viscosity and controlled penetration of the resin into the wood structure and hence better bonding. Concerning the wood species, beech had the highest stress carrying capacity that it can attributed to its higher density.

Environmental pollutions caused by petroleum polymers and the limitation of petroleum resources have led to the development of bio based polymers and progress in reducing dependence on fossil fuels. In recent years poly(vinyl alcohol) (PVA) has received much attention in paper coatings, films, packaging materials and biomedical fields because of water-solubility, nontoxicity, excellent chemical resistance, proper barrier and biodegradability properties. In spite of its growing use, information on its destruction, especially the role of Bactria in this process is relatively low. The aim of this study is isolation and identification of PVA degrading bacterium from the municipal solid wastes composted. Compost samples were collected from solid municipal wastes in Karaj Compost plant during the process of compost production. Poly (vinyl alcohol) films were prepared by using liquid nitrogen, freeze drying and hot press techniques. The specimens were buried in municipal solid waste for 150 days. Then, the number of bacteria was counted on the culture medium. Isolation of the bacterium was done by culturing the bacteria on poly (vinyl alcohol) films. New poly (vinyl alcohol) degrading bacteria were isolated from municipal solid waste composted by using enrichments on poly (vinyl alcohol) films. Then isolated bacterium was identified by PCR with 16S rDNA method. In this study, the maximum number of bacteria was 280±0.1 at a medium with poly (vinyl alcohol) films, and the minimum number of bacteria was 110±0.3 at control medium. Following molecular identification and sequencing of 16S rDNA gene, the BLAST showed high similarity sequence of the sample with Pseudomonas geniculate. This paper is the first report on polyvinyl alcohol degradation by Pseudomonas geniculate.

In this study Poly vinyl alcohol (PVA) and cellulose nanocrysrals (CNC) composite nanofibers were prepared by electrospinning process. To dissolve PVA, the deionized water was used due to environmental friendly of PVA. The design of experiments (DOE) was done by the Taguchi method using the Minitab for optimization of electrospinning. Polymer concentration was determined in 4, 6, 8 and 10% by solvent weight. Bead-free fibers were produced in 8% PVA concentration. CNC were added to polymer in 0.5, 1, 1.5 and 2% by PVA weight and DOE was applied for Needle to collector distance (cm), polymer concentration (%), polymer feed rate (mh/hr.) and applied voltage (Kv) were defined as variables, again to reach the thinnest fibers. Nanocomposites were soaked in GA 50% concentration for 48 hrs. to prevent nanocomposites decomposition. SEM and FESEM were used for morphological characterization. Diameter of the fibers was analyzed by Image software. Tensile, Modulus of Elasticity (MOE), Tension, Porosity, swelling and dissolving of nanocomposites were examined. Chemical reactions were traced by FTIR. Fibers with 87±16 nm in diameter were achieved in 0.5% CNC, 22 KV, 0.3 ml/hr. and 20 cm. Swelling and and solubility of nanocomposites were significantly improved by GA. FTIR spectra shows hemiacetal bounds produced during GA soaking. MOE and tensile were improved by CNC addition meanwhile tension and porosity were decreased. Same results were obtained for GA soaked nanocomposites.

In the recent years, rising oil prices, limiting these resources, and also environmental concerns raised by the increased consumption of plastic materials in the food packaging industry, increased global public concern. Recently, experts in the food packaging industry have sought to find suitable biodegradable substitutes for synthetic polymers. The nanocomposite of poly (butylene succinate) (PBS) and different content of cellulose nanofibers (CNF) including 5, 10 and 20 wt. % were prepared by solvent casting method and physical, mechanical and photodegradation properties of obtained cellulose nanocomposites were characterized. The photodegradation of materials was assessed by weight loss and FTIR spectroscopy. The tensile strength and elastic modulus of PBS films were improved by the addition of the cellulose nanofibers (CNF) compared to the neat polymer. The nanocomposite with 10 wt. % CNF had the highest tensile strength and lowest modulus of elasticity and the elongation at break. By adding the CNF, water vapor permeability decreased from 9.05×10-5 g/m.h.Pa for pure PBS film to 6.96×10-5 g/m.h.Pa for PBS film containing 10 wt. % cellulose nanofibers. In addition, the water uptake and contact angle properties were enhanced by the adding of cellulose nanofibers. The biodegradation results showed that the addition of CNF increased the percentage of the samples weight loss. Therefore, due to the results obtained, it can be concluded that the composites obtained in this study have the potential to be replaced with synthetic polymers.

This study was focused on the preparation of an environmentally friendly nanocellulose based hydrogel in the form of pads. Hydrogels are hydrophilic three dimensional network with crosslinks, swells in water but don’t dissolve. In this research nanofibrillated cellulose and Hydroxyethyl cellulose with different ratio (1:1, 2:1, 3:1) were used to make hydrogel. Also, citric acid which has a significant advantage over other crosslinking agents in terms of toxicity and price, has been used in different amounts of 10% and 20% by weight to crosslink. In order to find optimal hydrogel preparation conditions, FTIR analysis, FESEM, time dependent swelling measurement and evaluating the thermal and rheological properties were performed. Samples with a lower ratio of nanocellulose to hydroxyethyl cellulose were found to be inappropriate due to the loss of their apparent integrity in the swelling measurement. According to FTIR results, cross-linking were performed only in samples with the highest ratio of nanocellulose to hydroxyethyl cellulose in different amounts of citric acid. Therefore, the hydrogel's characteristics were mainly influenced by the ratio of nanocellulose to hydroxyethyl cellulose and the amount of citric acid had less effect on these properties. These two successful final samples showed acceptable properties in other evaluated properties and led to the selection of optimal reactive ratios for the preparation of hydrogels for use in various industries, including the pharmaceutical industry.