Cotton Pulp Research Articles

Maximizing the yield of nanocrystalline cellulose from cotton pulp fiber

Nanocrystalline cellulose (NCC) has attracted a significant interest in recent years as it is made from renewable resources and has many unique characteristics. In this paper, we prepared NCC from cotton pulp fiber by the method of sulfuric acid hydrolysis, with the objective of achieving a maximum yield. The yield and the particle size of NCC were measured as a function of sulfuric acid concentration, reaction temperature and hydrolysis time, and optimized by an orthogonal test. A high NCC yield of more than 60% was found when the sulfuric acid concentration is 64%, reaction temperature is 50°C and the hydrolysis time is 5h. The morphology and the size of NCC were characterized by scanning electron microscope (SEM) and particle size analyzer. The finding from this study should provide guidance in maximizing the yield of NCC from cotton pulps using acid hydrolysis.

Treatment of Cotton Pulp Black Liquor Using Micro-Electrolysis in Sequencing Batch Reactor

Micro-electrolysis process was conducted to treat the anaerobic digestion effluent of cotton pulp black liquor in sequencing batch reactor (SBR). Three key factors including reaction time, pH, and iron-carbon volume ratio were investigated for their impacts on the treatment efficiency. The effluent of micro-electrolysis polished by coagulation process was performed with Al2(SO4)3and PAC as coagulators. The results show that the optimum conditions of the micro-electrolysis treatment were pH 5.5, iron-carbon volume ratio 1:1, and reaction time 8h. Al2(SO4)3was selected as the coagulator with the addition of 400mg/L. The removal efficiency of COD reaches 93.2% with Micro-electrolysis combined with coagulation process. In addition, the B/C ratio has risen from 0.016 to 0.68(>0.3), which creates favorable conditions for the subsequent aerobic process. Consequently, the micro-electrolysis and coagulation process are highly efficient to dispose the anaerobic digestion effluent of cotton linters pulp black liquor. What’s more, this technology has the advantages of low operating cost, small land occupation and high efficiency.

Treatment of Cotton Pulp Black Liquor Using Micro-Electrolysis in Sequencing Batch Reactor

Treatment of Cotton Pulp Black Liquor Using Micro-Electrolysis in Sequencing Batch Reactor

Study of the Structure and Oxygen Permeability of Cellulose Packaging Films from NMMO-Solutions

This paper is concerned with the preparation of cellulose packaging films with high oxygen permeability. The films were prepared from cotton pulp and wood pulp by the cast-wiped method using N-methymorpholine-N-oxide (NMMO) as a solvent. The effects of processing parameters on the structure and performance of cellulose films were also studied. The results show that for optimum processing of the films cotton pulp was the preferred raw material, the optimum pulp concentration in the casting solution was 5%, and the optimum temperature for the coagulation bath was 40°C. Using the above process conditions resulted in packaging films with high oxygen permeability making them suitable for use in packaging fruits and vegetables.

Study of Cellulose-Dibutyl Sebacate Copolymer Synthesis and Characterization of Crosslinked Cellulose-Dibutyl Sebacate Copolymers for Oil Absorbency

A novel cellulose-based oil absorbent crosslinked cellulose-dibutyl sebacate copolymers was prepared by the graft crosslinking polymerization of in situ synthesized dibutyl sebacate and cotton cellulose using potassium persulfate as an initiator. The copolymers were characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetry, differential scanning calorimetry, etc. The effects of reaction conditions, such as, ratio of reaction regents, reaction temperature, reaction time, etc, on the efficiency of oil absorbency were examined. The optimized reaction conditions for the synthesis of crosslinked cellulose-dibutyl sebacate copolymers were: m(cotton pulp):m(K2S2O8 initiator):m(dibutyl sebacate) = 1 0.025 2.0(W/W)，75°C，and 5-6 h. The resulting crosslinked cellulose-dibutyl sebacate copolymers were floppy and exhibited excellent oil absorbency efficiency.

Research on Pollution-Free Separation of Wheat Straw Cellulose by Ethanol/Acetic Acid Solvent System

Agriculture wastes-- wheat straw is used as raw material to take place of cotton and wood pulp in this research. In order to separating of the crude cellulose, non-polluting ethanol/acetic acid binary solvent system is utilized to dissolve lignin. Then pure cellulose is obtained by refining processing. Finally, microcrystalline cellulose is obtained by acid hydrolysis, grinding and the subsequent process. The paper focuses on the effect of the dosage of acetic acid in the binary solvent system on separating efficiency of wheat straw cellulose, and analyzing the effects of acetic acid dosage on kappa number, yield, α-cellulose content and crystallinity of the wheat straw crude cellulose. The results indicated that acetic acid can promote the removal of lignin and hemicellulose degradation, and is conducive to improve the purity of crude fiber. The lignin removed mainly adsorbed and deposited onto the surface of crude cellulose. The optimum dosage of acetic acid in the thermal decomposition system of wheat straw is 2%. Under the optimum condition, the crystallinity of crude cellulose is the highest, the yield and α-cellulose content are both rather high, but a low Kappa number.

Rheological properties of cotton pulp cellulose dissolved in 1‐butyl‐3‐methylimidazolium chloride solutions

AbstractRheological properties of cotton pulp dissolved in 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl) solutions were characterized using an advanced rheometer. The complex viscosity, dynamic modulus, and shear viscosity at different temperature were studied. In the steady shear measurements, all the solutions show a shear‐thinning behavior at high shear rates. The complex viscosity as a function of frequency was fitted by extended Carreau–Yasuda model. In all cotton pulp/[Bmim]Cl solutions, the complex dynamic viscosity (η*) and steady shear viscosity (ηa) followed the Cox–Merz rule only at lower frequency. The effects of tested temperature on viscosity and viscoelastic behavior of the solutions were also investigated. The value of activation energy for the dissolution of cotton pulp in ionic liquids was 65.28 kJ/mol at the concentration of 10 wt% and was comparable with the ones for the dissolution of cellulose in NMMO. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Preparation and Characterization of Wheat Straw MCC

During the wet PU, PVC synthetic production, MCC could be served as a good micropore and thickening agents, and could obviously enhance the feel and elasticity of synthetic leather, but cotton pulp and wood pulp resources, which were used as raw material commonly to produce MCC for synthetic leather, was limited. In this paper, MCC was prepared with wheat straw pulp through the dilute acid hydrolysis, alkali treatment, enzyme treatment, drying and crushing. This paper focused on the effect of conditions of acid hydrolysis on performance of MCC, and the optimization of process parameters. The morphology, size, crystallinity and thermostability of MCC were characterized by scanning electron microscopy, X-ray diffraction, TGA spectrograph. Wheat Straw MCC could meet the requirements of synthetic leather industry standards for MCC.

Chemical and radiation-chemical radical reactions in lignocellulose materials

Chemical and radiation-chemical radical reactions in lignocellulose materials were explored by 3-cm and 2-mm ESR spectroscopy. Background (intrinsic) singlet signals at g=2.003 from wood pulp and lignin and those arising during reaction of lignocellulose materials with acids and chlorine were attributed to radicals with conjugated CC bonds. The 2-mm ESR signal with 3D anisotropy of g-factor from o-semiquinone radical ions formed in reaction of lignin with NaOH was recorded for the first time. The singlet signals derived from cellulose γ-irradiated at 77 K and marked out during post-thermal reactions were assigned to radicals with conjugated bonds. In wetted cellulose, a triplet signal with α β H ≅2.7 mT and imposed quadruplet structure (0.5–0.7 mT) from three γ-protons was detected at 300 K and attributed to С 4-radicals. The triplet signals derived from С 2- and С 3-radicals in pyranose cycles of cellulose exhibited higher values of α β H (3.0–3.2 mT) and lower thermal stability (up to 250 K). In radiolyzed cotton pulp, detected were ESR signals derived from formyl radicals formed upon rupture of the С 5С 6 bond in pyranose cycles. Heating up irradiated samples under О 2 was accompanied by formation of peroxide radicals. Photoinduced recombination of trapped electrons with С 1-radicals was found to proceed as a chain reaction with a kinetic length of about 25 units. Photolysis ( λ≥360 nm) of radiolyzed cellulose enhanced the disclosure of pyranose cycles and, as a result, the evolution of CO 2 by a factor of 2–2.5.

Characterization of the regenerated cellulose films in ionic liquids and rheological properties of the solutions

Dissolution and regeneration of cotton pulp using ionic liquids as solvent was investigated. The physicochemical properties of the regenerated cellulose films have been characterized by scanning electron microscopy, X-ray diffractometer, infrared spectrometric analyzer, differential scanning calorimeter, and thermogravimetric analysis instrument. The rheological properties of cotton pulp dissolved in ionic liquids have been investigated by steady shear and oscillatory shear measurements. The influences of experimental parameters, such as the reaction temperature, additives on the solubility and degree of polymerization (DP) of regenerated cellulose were also studied. The results show that 1-butyl-3-methylimidazolium chloride ([bmim]Cl) was a good solvent to dissolve cotton pulp and the solubility can reach 13 wt% at 90 °C, but the DP remarkably decreased from 510 to 180 within 7 h. It was found that additive N-methylimidazole can effectively minimize DP loss of the regenerated cellulose, which can attribute to the fact that in the mixture of [bmim]Cl and NMI solution, the β-1,4-glycosidic bond of the cellulose chains cannot be broken because of the relative low concentration of Cl −. In the steady shear measurement, all the solutions show a shear thinning behavior at high shear rates. In addition, a mechanism of the dissolution of cellulose in [bmim]Cl was proposed.

The Feasibility Study of Cotton Pulp Wastewater Treatment with IC Anaerobic Reactor

Abstract IC anaerobic reactor can deal with the diluted cotton pulp wastewater with SCOD concentration of 3500mg/l well, the removal rate could reach 68% at the volume load of 18kgcod/m3.d; With regard to the raw cotton pulp wastewater with SCOD concentration 6600mg/l, the removal rate could reach 60% at the volume load of 16kgcod/m3.d, better than the existing pretreatment process with the removal rate of 40%-50%.

Multi-walled carbon nanotubes–cellulose paper for a chemical vapor sensor

This paper reports the multi-walled carbon nanotubes (MWCNTs)–cellulose paper as a chemical vapor sensor. Cellulose solution was prepared by dissolving cotton pulp in LiCl/N,N-dimethylacetamide solution. MWCNTs were covalently grafted to cellulose by reacting imidazolides–MWCNTs with cellulose solution. Using this product, the MWCNTs/cellulose (M/C) paper was fabricated, followed by mechanical stretching to align MWCNTs with cellulose chains. Characteristics of the M/C paper were analyzed in terms of scanning electron microscope images, Young's modulus and electrical resistance. The M/C paper was investigated as a chemical sensor that can detect vaporized analyte molecules, such as, methanol, ethanol, 1-butanol and 1-propanol. Their electrical responses on the sensor were evaluated by not only comparing their relative resistance response ( A R ) depending on the concentration, but also checking signal reversibility under cyclic exposure of each analyte. Due to sensitive and reversible expansion/contraction of the M/C paper in response to analytes, the M/C paper showed reversible and fast response with the following rank of A R : methanol < ethanol < 1-propanol < 1-butanol. Especially, the linear response to 1-propanol concentration proved that the M/C paper can be a qualified sensor for n-propanol.

The effects of carbon disulfide on male sexual function and semen quality

A cross-sectional study was initiated to clarify whether the current level of exposure to carbon disulphide (CS(2)) is low enough to prevent occurrence of subclinical health impairments. This paper describes the effects of exposure to CS(2) on male sexual function and semen quality in a baseline observation. The effects of CS(2) on male sexual function were evaluated, including number of sexual encounters and length of sexual encounters related to solvents in 80 male workers exposed to CS(2) and 49 reference workers from the filature and cotton pulp departments of a fabric factory in China. And the semen samples were obtained from 43 of the exposed and 35 of the control. Adjustment was made for potential confounding factors such as age or alcohol drinking. Exposure to CS(2) was dichotomized by job type. The rate of sexual dysfunction was higher, number of sexual encounters was lower, and length of sexual encounters was shorter compared with the control (p < 0.001). It was indicated that exposed workers had fewer semen quantity, longer liquefaction time, lower acrosomal membrane integrity rate, vitality and density, and more deformity of semen than the control (p < 0.01). The age and type of work played the most important roles in sexual dysfunction by the multinomial logistic regression analysis (p < 0.01).The duration of exposure had the effect on sexual function and semen quality but no statistical significance (p > 0.05). Clinical effects on the male sexual function and semen quality were found in the workers exposed to CS(2).

Biological treatment of high-pH and high-concentration black liquor of cotton pulp by an immediate aerobic-anaerobic-aerobic process

In this study, an immediate aerobic-anaerobic-aerobic (O/A/O) biological process was established for the treatment of black liquor of cotton pulp and was tested by both laboratory-scale batch experiment and pilot-scale continuous experiment. The effects of the hydraulic retention time (HRT) were studied, as were the alkaliphilic bacteria number, the culturing temperature and the concentration of black liquor on COD (chemical oxygen demand) removal. The total COD (COD(tot)) removal rate of the novel O/A/O process, for a black liquor with influent COD(tot) over 8,000 mg/L and pH above 12.8, was 68.7+/-4% which is similar with that of the traditional acidic-anaerobic-aerobic process (64.9+/-3%). The first aerobic stage based on alkaliphilic bacteria was the crucial part of the process, which was responsible for decreasing the influent pH from above 12 to an acceptable level for the following treatment unit. The average generation time of the alkaliphilic bacteria in the black liquor was about 36 minutes at 40 degrees C in a batch aerobic activated sludge system. The efficiency of the first aerobic stage was affected greatly by the temperature. The COD(tot) removal at 55 degrees C was much lower in comparison with the COD(tot) removal at 45 degrees C or 50 degrees C. Both the laboratory-scale batch experiments and the pilot-scale continuous experiment showed that the COD(tot) removal rate could reach about 65% for original black liquor with a pH of about 13.0 and a COD of 18,000-22,000 mg/L by the immediate O/A/O process. The first aerobic stage gave an average COD(tot) removal of 45.5% at 35 degrees C (HRT = 72 h) at a volume loading rate of 3.4 kg COD m(-3) d(-1).

Electrically aligned cellulose film for electro-active paper and its piezoelectricity

Electrically aligned regenerated cellulose films were fabricated and the effect ofapplied electric field was investigated for the piezoelectricity of electro-active paper(EAPap). The EAPap was fabricated by coating gold electrodes on both sides ofregenerated cellulose film. The cellulose film was prepared by dissolving cotton pulp inLiCl/N,N-dimethylacetamide solution followed by a cellulose chain regeneration process. Duringthe regeneration process an external electric field was applied in the direction ofmechanical stretching. Alignment of cellulose fiber chains was investigated as afunction of applied electric field. The material characteristics of the cellulosefilms were analyzed by using an x-ray diffractometer, a field emission scanningelectron microscope and a high voltage electron microscope. The application ofexternal electric fields was found to induce formation of nanofibers in the cellulose,resulting in an increase in the crystallinity index (CI) values. It was also foundthat samples with higher CI values showed higher in-plane piezoelectric constant,d31, values. The piezoelectricity of the current EAPap films was measured to be equivalent orbetter than that of ordinary PVDF films. Therefore, an external electric field applied to acellulose film along with a mechanical stretching during the regeneration process canenhance the piezoelectricity.

Covalently bonded multi-walled carbon nanotubes-cellulose electro-active paper actuator

Covalently bonded multi-walled carbon nanotubes (MWNTs) to cellulose were used to fabricate electro-active paper (EAPap) and its mechanical properties as well as actuator performance were investigated. A cellulose solution was prepared by dissolving cotton pulp in LiCl/ N, N-dimethylacetamide (DMAc) solution. MWNTs were covalently bonded to cellulose by reacting MWNTs-imidazolides with cellulose solution. Using this, MWNTs/cellulose (M/C) EAPap was fabricated with different weight percents of MWNTs. This EAPap was analyzed by Fourier-transform IR, X-ray diffraction and X-ray photoelectron spectroscopy and their Young's modulus was measured. The actuator performance of M/C EAPap was evaluated in terms of bending displacement, resonance frequency and electrical power consumption depending on the weight percent of MWNTs and humidity levels. Due to the presence of covalent bonds between MWNTs and cellulose, the Young's modulus of M/C EAPap was remarkably enhanced more than the MWNTs blended EAPap. The enhanced Young's modulus was strongly associated with the crystallinity change of cellulose. The actuator performance of M/C EAPap was improved also. More explanation about the characteristics, actuation principle and actuator performance of M/C EAPap actuator is addressed.

Nesterenkonia alba sp. nov., an alkaliphilic actinobacterium isolated from the black liquor treatment system of a cotton pulp mill

An alkaliphilic actinobacterium, designated strain CAAS 252(T), was isolated from the black liquor treatment system of a cotton pulp mill in Wuhan, China. Cells of strain CAAS 252(T) were Gram-positive, non-motile, non-endospore-forming, short rod-shaped, and grew optimally at 42 degrees C and pH 9-10 in the presence of 3 % (w/v) NaCl. Strain CAAS 252(T) contained MK-7, MK-8 and MK-9 as the major menaquinones and anteiso-C(17 : 0), anteiso-C(15 : 0) and C(16 : 0) as the predominant cellular fatty acids and had a peptidoglycan type of A4alpha, Lys-Gly-d-Asp. The DNA G+C content was 60.2 mol%. Based on analysis of 16S rRNA gene sequences (94.7-96.8 % similarity), DNA-DNA hybridization (<70 % relatedness) and chemotaxonomic characteristics, strain CAAS 252(T) belonged to the genus Nesterenkonia, but differed from all recognized species. Therefore, it is proposed that strain CAAS 252(T) represents a novel species of the genus Nesterenkonia, for which the name Nesterenkonia alba sp. nov. is proposed. The type strain is CAAS 252(T) (=CCTCC AB 207011(T)=DSM 19423(T)).

Decolorization of Cotton Pulp Black Liquor by Pleurotus ostreatus in a Bubble-column Reactor

Decolorization of cotton pulp black liquor by Pleurotus ostreatus B1 in a bubble-column reactor (BCR) was studied. The optimal conditions for the running of BCR are 30 degrees C, pH 6.0, aeration rate 1.2 L min(-1), and mycelial age 7 days. Under the optimal conditions, the BCR was run for four cycles (each cycle, 12 days) and the same mycelial pellets were reused. The ultimate decolorization and COD removal rates are 76% and 80%, respectively.

Effect of aligned cellulose film to the performance of electro-active paper actuator

This study focused on investigating the effect of aligned cellulose fibers to the performance of EAPap actuator. Among the several factors affecting the performance of EAPap, influence of material orientation in the chemical and physical processing would be crucial for cellulose film. A well-known electrospinning method was employed to improve material orientation of EAPap. LiCl/DMAc cellulose solution, which cotton pulp was dissolved in lithium chloride (LiCl) and N, N-dimethylacetamide (DMAc) solvent, was used for the fabrication of electrospinning cellulose film. The electrospun cellulose film was spincoated to fill internal pores and stretched up to 10% strain by wet drawn process. SEM images were provided to show aligned cellulose film obtained by the proposed electrospinning and wet drawn stretching method. XRD patterns showed that samples fabricated by electrospinning and stretching method enhanced both crystal structure and crystallinity of cellulose film, which are associated with the improvement of piezoelectricity of EAPap. Induced in-plane strain of electrospun EAPap was proportional to the applied voltage and larger than that of spincast EAPap. An attempt to align cellulose fibers by electrospinning is a useful method for improving the performance of EAPap actuator.

Production and partial characterization of cellulase free xylanase by Bacillus subtilis C 01 using agriresidues and its application in biobleaching of nonwoody plant pulps

To optimize the solid-state cultivation conditions for xylanase production using agriresidues and testing the biobleaching efficiency of xylanase on nonwoody plant fibre materials. An extracellular cellulase free xylanase was produced from Bacillus subtilis C 01 using various inexpensive substrates under solid-state cultivation. High level of xylanase production (135 IU gds(-1)) was observed when grown on wheat bran followed by maize powder (50 IU gds(-1)). The maximum xylanase (136 IU gds(-1)) production was occurred in wheat bran-to-moisture ratio of 1 : 1 at 72 h. The xylanase pretreated pulp samples of banana, silk cotton and cotton showed an increased brightness of 19.6, 11.6 and 7.9%, respectively. The enzyme-aided biobleaching results indicate that the xylanase has potential application in enhancing the brightness of nonwoody plant fibre pulp. This is the first report on biobleaching of banana fibres, silk cotton and cotton pulps using xylanase. The biobleaching results of secondary fibres are promising and can be transferred to paper mills, which utilize nonwoody plant fibres as a raw material for paper production.