Cellulose Powder Research Articles

A numerical study of the influence of operating conditions of a blade free planetary mixer on blending of cohesive powders

A blade-free planetary mixer provides an effective and rapid mixing of cohesive powders due to its powerful centrifugal agitation capability to produce a swirling flow pattern in a mixing vessel. Despite its popular use in the powder processing industry, the dynamics and characteristics of blade-free planetary mixing are still not well understood because of a lack of experimental and numerical studies. This paper presents a discrete element study of the influence of operating parameters such as the steady-state revolution speed and the rotation-to-revolution speed ratio on bending of pharmaceutical powders with specific cohesiveness. The particle-level cohesive forces were calculated using the Johnson-Kendall-Roberts cohesion model. A series of discrete element simulation was carried out at some range of revolution and rotation speeds of a mixing vessel. The degree of mixing in each simulation was quantified with the mixing index and mixing time. The simulation results showed a faster rotation speed and a higher rotation-to-revolution ratio provided more effective mixing of the specific microcrystalline cellulose powder. The methodology and results of this numerical study can be used to determine the optimal operating conditions of a blade-free planetary mixer for effective mixing of cohesive powders.

Effects of Intranasal Cellulose Powder on Asthma Control in Children With Mild-to-Moderate Perennial Allergic Rhinitis: A Randomized, Placebo-Controlled Trial

Perennial allergic rhinitis (PAR) often coexists in asthmatic patients. Intranasal cellulose powder (ICP) was reportedly effective in ameliorating PAR. We investigated whether ICP is equally effective compared with intranasal corticosteroids in improving asthma control as well as nasal symptoms among children with PAR and allergic asthma (AA). Between July 2015 and September 2016, we did a single-center, randomized, placebo-controlled trial. Asthmatic children aged 6 to 11 years with mild-to-moderate PAR were randomly assigned to formoterol/budesonide inhalation (4·5 µg/80 µg, twice daily) plus intranasal budesonide 64 µg twice daily (group A), ICP 250 µg thrice daily (group B), or intranasal placebo 250 µg thrice daily (group C) for 8 weeks. The primary outcome was change in asthma control test for children (C-ACT) score from baseline to week 8 posttreatment. Changes in spirometry, peak expiratory flow (PEF), fractional exhaled nitric oxide (FeNO), and visual analog scale (VAS) for nasal and ocular symptoms were detected as secondary outcomes. We included 121 patients (38 in group A, 41 in group B, and 42 in group C) in full-analysis set. C-ACT score was markedly higher at week 8 compared with baseline (mean difference: 5.11, 6.05, and 4.85 points in groups A, B, and C, respectively; P < .05). There were interactions between baseline and treatment in C-ACT scores ( P < .05). Group B demonstrated greater improvement in C-ACT score than group C among children with baseline C-ACT score of 6 to 18. 95% confidence intervals of group A at baseline overlapped with those of groups B and C. The treatment achieved reduced VAS symptoms in groups A and B but not in group C. Incidence of adverse events was comparable. No serious adverse event was reported. ICP could be recommended for children with PAR and AA who have poorer asthma control.

CHARACTERIZATION OF HYDROXYPROPYL CELLULOSE PRODUCED FROM α-CELLULOSE BETUNG BAMBOO (DENDROCALAMUS ASPER) AND IT’S APPLICATION IN TABLET FORMULATION

Objective: This study aimed to obtain the physicochemical properties of hydroxypropyl cellulose (HPC) powder from α-cellulose Betung bamboo and its characteristics in tablet formulation.&#x0D; Methods: HPC was prepared by hydroxypropylation of α-cellulose using 25% (w/v) sodium hydroxide and 10 ml propylene oxide (based on 1 g α-cellulose) at 70 °C for 3 h. HPC of Betung bamboo (HPC BB) was characterized using fourier transform infrared (FTIR) spectrometry, particle size analyzer (PSA), x-ray diffraction (XRD), scanning electron microscope (SEM) and compared to HPC grade SL (HPC SL) as the reference. Then, HPC BB was used as a binder in tablet formulation by direct compression method and the resulted tablets were evaluated. The tablets evaluation including weight and size uniformity, hardness, friability and disintegration time.&#x0D; Results: The results showed HPC BB powder was yellowish white, odorless and tasteless, pH 7.49, residue on ignition 0.68%, hydroxypropoxy groups content 54.75%, average particle size 37.39 μm, loss on drying 1.09%, and moisture content 3.34%. Flow properties of powder fulfilled the requirements based on literature. Infrared spectrum and diffraction pattern of HPC BB were relatively similar to HPC SL. The tablets have average weight 403.495 mg, diameter 12.16 mm, thickness 3.11 mm, hardness 4.11 KPa, friability 2.04% and disintegration time 24.88 s.&#x0D; Conclusion: Based on the comparison of powder characteristics and tablets evaluation, HPC BB has a great potential in tablet formulation which showed similar characteristics to reference.

Effect of fixation conditions on yellowing behavior of cellulose powder–coated fabrics

In this study, the yellowing behavior of cellulose powders, which is applied to pretreated polyester woven fabrics with concentrations of 100 g/kg by knife coating technique, was investigated. After drying process, coated fabrics were cured at different conditions to determine the effects of the curing temperature and time on yellowing behaviors. The yellowness–whiteness of coated fabrics was measured with a spectrophotometer according to ASTM E313. As the curing temperature and time increase, yellowing effect was more observable. However, the effect of temperature increase is found to be more significant than the increase in curing duration in terms of more observed yellowness. In order to investigate the reason of yellowing, cellulose powder samples were heated in drying oven at three different heating temperatures (130°C, 150°C, and 170°C) for three different heating periods (3, 5, and 7 min). Then, thermal gravimetric analysis and Fourier transform infrared spectroscopy analysis of powder samples were performed for each temperature–period combinations. No ring-opening reaction on the cellulose group was found in the Fourier transform infrared spectroscopy analysis. However, the changes in the spectra can be attributed to the chain breakage in the cellulose macromolecules as well as water loss from the molecular structure during the heating process. Microscopic and scanning electron microscopic analysis was carried out to see any surface change on the fiber and coated fabric. There was no detectable surface change on the fiber and coated fabric surface, apart from a color change on the fabric surface.

A simple, ex vivo phagocytosis assay of Plasmodium vivax merozoites by flow cytometry.

As phagocytosis is the first line of defense against malaria, we developed a phagocytosis assay with Plasmodium vivax (P. vivax) merozoites that can be applied to evaluate vaccine candidates. Briefly, after leukocyte removal with loosely packed cellulose powder in a syringe, P. vivax trophozoites matured to the merozoite-rich schizont stages in the presence of the E64 protease inhibitor. The Percoll gradient-enriched schizonts were chemically disrupted to release merozoites that were submitted to merozoite opsonin-dependent phagocytosis in two phagocytic lines with human and mouse antibodies against the N- and C-terminus of P. vivax Merozoite Surface Protein-1 (Nterm-PvMSP1 and MSP119). The resulting assay is simple and efficient for use as a routine phagocytic assay for the evaluation of merozoite stage vaccine candidates.

3-D magnetic graphene balls as sorbents for cleaning oil spills

A 3-D magnetic graphene ball (MGB) material was prepared using cellulose as the carbon source. Carbon-encapsulated iron nanoparticles (CEINs) were first prepared by hydrothermal carbonization of cellulose powder at 180°C. Then, the prepared CEINs were catalytically graphitized to graphene-encapsulated iron nanoparticles (GEINs) at 900°C. Finally, GEINs were treated in carbon dioxide at 700°C, during which the iron core was oxidized to magnetite (Fe3O4) nanoparticles, and graphene shells were peeled off from the iron cores to form graphene nanoplatelets. The graphene nanoplatelets consist of 1–10 layers graphene with the in-plane size of 20–30 nm. The prepared 3-D MGB was investigated for the removal of oil from water, which demonstrated outstanding adsorption performance and excellent recyclability.

Drying and disaggregation of cotton powder cellulose in the flash drying unit

The issues related with the drying and disaggregation of the cotton powder cellulose (CPC) in the flash drying unit are being discussed, as well as the properties of the cotton powder cellulose are being analyzed as the subject of drying and processing treatment.

Study the Effect of adding Carboxy Methyl Cellulose Powder to Low Density Polyethylene on Shielding Radiation for the X-ray

The attenuation measurements of x-ray of voltage range (21kv) for hosted polymer material were done using x-ray unit, in order to extract the effect of adding carboxy methyl cellulose material (CMC) to low density polyethylene on x-ray radiation attenuation . The linear attenuation coefficient (µl ) was calculated for the voltage range mentioned above , through linear equations of the yield of graphic representation between the logarithmic absorption and the sample thickness X(cm). The mass attenuation coefficient (µm ) could also be calculated through the graphic relation between the logarithmic absorption and the equivalent thickness of the sample Xm(gm/cm2 ) such that slope of the graphic relation represents linear the attenuation coefficient or mass attenuation coefficient. The calculated results indicated that the efficiency of prepared material to absorb X-ray and to attenuate it were high. This efficiency change relatively according to the added ratio and on type of material .This indicate a significant positive result for these adders on the characteristic radiation attenuation of the polymer,1 low density polyethylene.

Variation of scattering intensity ratios with mean atomic number using a dilution technique in EDXRF

The variation of different intensity ratios with mean atomic number for qualitative analysis was investigated in EDXRF. Ten different samples with a mean atomic number between 4.268 and 5.786 were obtained by mixing zirconyl chloride octahydrate (Cl2OZr·8H2O) and cellulose (C6H10O5) powders. The samples were excited by 59.54 keV gamma rays emitted from a 241Am annular radioactive source with 5 Ci activity. The high purity germanium (HPGe) semiconductor detector with a resolution of 182 eV at 5.9 keV was used to detect the photons. (Icoh/2(μ/ρ)λ+Icomp/(μ/ρ)λ+(μ/ρ)λ−Δλ), (Icoh+IComp)/(μ/ρ)λ, (Icoh/2(μ/ρ)λ, IKα/Isc and IKβ/Isc intensity ratios in XRF spectrum for the assessment of information regarding the mean atomic number of the samples are studied. It has been observed that the total scattering intensity ratios can be used with high reliability in qualitative analysis for complex materials.

Therapeutic effects of a liquid bandage prepared with cellulose powders from Styelaclava tunics and Broussonetiakazinoki bark: Healing of surgical wounds on the skin of Sprague Dawley rats.

Cellulose in different forms has extensively been applied in biomedical treatments, including scaffolding, tissue engineering and tissue formation. To evaluate the therapeutic effects of a liquid bandage (LB) prepared with cellulose powders from Styela clava tunics (SCT) and Broussonetia kazinoki bark (BSLB) for healing cutaneous wounds, the remedial effects of a low concentration (LoBSLB) and a high concentration (HiBSLB) of BSLB on skin regeneration and toxicity in Sprague Dawley rats. Results indicated that the total area of skin involved in the surgical wound was lower in the BSLB-treated group compared with the Vehicle-treated group at days 4–12, although some variations were observed in the HiBSLB-treated group. In addition, the BSLB-treated group showed significantly enhanced width of the re-epithelialization region and epidermal thickness when compared with the Vehicle-treated group. Furthermore, significant stimulation in the expression level of collagen-1 and the signaling pathway of VEGF after topical application of BSLB was indicated. No liver or kidney toxicities were detected for either doses of BSLB. Overall, the results of the present study suggest that BSLB accelerates the process of wound healing in surgical skin wounds of Sprague Dawley rats through stimulation of re-epithelialization and connective tissue formation, without any accompanying significant toxicity.

Effect of Cellulose Powder on Human Nasal Epithelial Cell Activity and Ciliary Beat Frequency

Background: Cellulose powder (CP) has been reported as a safe and effective complementary treatment for allergic rhinitis (AR). Currently, CP has gained increasing application for clinical management worldwide, particularly in China. However, studies focusing on the effect of CP on normal human nasal epithelial cells (hNECs) and ciliary function are lacking. Here, we aimed to explore the adverse effects of CP on the activity and ciliary function of hNECs. Methods: We biopsied ethmoid sinus or middle turbinate tissues during surgical resection from control subjects who underwent endoscopic sinus surgery for diseases other than AR. Cells were isolated and passaged, followed by differentiation in an air-liquid interface (ALI). Flow cytometry and cell viability test (cell counting kit-8) were performed to detect the cytotoxicity of CP (effects on cell proliferation) on normal hNECs. By using the ALI culture model, we investigated the effects of CP on ciliary beat frequency (CBF). Results: There was a significant reduction in hNEC count at high concentrations of CP (2.5 mg/mL) at days 3 and 7 (both p < 0.05). As the concentration increased, cell death increased progressively from day 3 to day 7. However, these effects were not evident at low concentrations (0.25 mg/mL, p > 0.05). High-dose CP (2.5 mg) significantly reduced the CBF (p < 0.05). At lower concentrations (0.25–2.5 mg/mL), CP initially increased but subsequently reduced the CBF of hNECs compared with control group. Conclusions: Cytotoxicity and the suppression of ciliary beat at high concentrations justify more prudent use of CP for the management of AR.

Functionalized Cellulose‐Co(II)‐Bis‐Terpyridine Hybrid Material as Colorimetric Sensor for Micromolar Aqueous Cyanide

AbstractA novel surface modification approach is taken to cyanide‐sensing by using functionalized cellulose surface that is chemically modified by immobilizing cobalt(II)‐bis‐terpyridine complex on it. The cobalt(II)‐bis‐tpy complex can exhibit selective “naked eye” colorimetric detection of micromolar level cyanide in aqueous solution, where the visible red‐orange color of cobalt(II)‐bis‐tpy complex solution (aqueous) disappears in the presence of cyanide ions. In order to make the sensor more proficient and easy to use, these cobalt(II)‐bis‐tpy molecules are chemically grafted on the surface of microcrystalline cellulose and cellulose paper, which turns the color of functionalized cellulose orange‐red. Both of these colored cellulose powder and paper exhibit color loss in 10−6m aqueous solution of potassium cyanide. This functionalized hybrid inorganic–organic paper offers an easy “dip and detect” cyanide sensing.

Quantification of accessible hydroxyl groups in cellulosic pulps by dynamic vapor sorption with deuterium exchange

Dynamic vapor sorption (DVS) coupled with deuterium exchange was applied in determining the amount of hydroxyl (OH) groups accessible for deuteration in pulps and pure cellulose quantitatively. The samples studied with the method were different types of chemical pulps as well as microcrystalline and amorphous cellulose powders. The measurement sequence consisted of drying the samples first until the change in sample mass was less than 0.0005% min−1 followed by rewetting the sample with deuterium oxide (D2O) vapor at set relative humidity (RH) of 95% for 600 min and then drying the sample again the same way as the initial drying was done. The method allows determination of the absolute amount of OH groups accessible to deuterium exchange in the samples fully automatically within 1 day. In addition, the equilibrium moisture contents (EMC) of the samples were measured at RH 95% without prior drying enabling the assessment of the EMC of the samples in as-received state without the need to assess the effect of drying. The accessibilities of chemical pulps were found to vary between 54 and 61% of the theoretical maximum, whereas the accessibilities of microcrystalline cellulose and amorphous cellulose were 51 and 63%, respectively. Interestingly, it was found that the accessible OH group content and the EMC of the samples in mol kg−1 correlated with each other and that, in fact, their ratio was close to one.Graphical abstract

Effect of aminated nanocrystal cellulose on proton conductivity and dimensional stability of proton exchange membranes

A functionalized nanocrystal cellulose bearing amino and sulfonic acid groups (Am-sNCC) is prepared through a two-step chemical modification of microcrystal cellulose powders, first by sulfonic acid and then by a 3-trimethoxysilyl propyl ethylenediamine. The structure of Am-sNCC is characterized by Fourier Transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). A sulfonated poly(ether ether ketone ketone) (Ph-SPEEKK) is synthesized via the direct sulfonation of a high-molecular-weight phenylated polymeric precursor under a mild reaction condition. The nanocomposite membranes composed of the Ph-SPEEKK matrix and the Am-NCC additive are successfully prepared by a solution casting method. The properties related to their application for proton exchange membranes are carefully evaluated. The nanocomposite membranes containing Am-sNCC, which served as a performance-enhancing component to form hydrogen bonding networks with the Ph-SPEEKK matrix, exhibited much improved dimensional stability, higher water absorption capacities, higher proton conductivity, better mechanical and fuel cell properties than the Ph-SPEEKK membrane.

Effective Concentration of Ionic Liquids for Enhanced Saccharification of Cellulose

In an aqueous enzymatic saccharification using cellulase, the dissolution of crystalline cellulose is one of the rate-limiting steps. Insoluble cellulose powder was preliminarily heat-treated with ionic liquids (ILs), such as [Bmim][Cl] (1-butyl-3-methylimidazolium chloride) and [Amim][Cl] (1-allyl-3-methylimidazolium chloride), which enable the production of soluble cellulose. On the other hand, the presence of ILs leads to a denaturation of enzymes. Using cellulase from Trichoderma viride, the effects of [Bmim][Cl] and [Amim][Cl] in the enzymatic saccharification were compared. The production of glucose was optimized with 5 wt%-ILs, both for [Bmim][Cl] and for [Amim][Cl]. The significant inhibiting effects of ILs (IL concentration &gt;10 wt%) could be due to the denaturation of cellulase, because the peak shifts of intrinsic tryptophan fluorescence were observed in the presence of 7.5 wt%-ILs. To analyze kinetic parameters, the Langmuir adsorption model and the Michaelis-Menten model were employed. The investigation suggests that [Amim][Cl] can provide soluble cellulose more efficiently, and can promote enzymatic saccharification in the IL concentration below 5 wt%.

Porous cellulose paper as a light out coupling medium for organic light-emitting diodes

ABSTRACTPorous nanocellulose paper was fabricated and applied as a light outcoupling medium. The nanocellulose papers were prepared using cellulose powder and a high-pressure homogenizing process. The translucent nanocellulose paper had high total transmittance and haze, and gave off diffuse light when the incident light passes through it. Through the application of the fabricated nanocellulose paper on the external surfaces of organic light-emitting diode (OLED) devices, it was possible not only to enhance the luminous efficiency but also to widen the angular light distribution. As this paper is intrinsically flexible, it can be applied to various forms of light sources bearing curvature.

Extraction of Nanocellulose from Dried Rubber Tree Leaves by Acid Hydrolysis

Nanocellulose were extracted from dried rubber tree leaves by acid hydrolysis. The dried rubber tree leaves were treated by the alkali and bleaching process to obtain the bleached cellulose powder. Acid hydrolysis from sulfuric acid (H2SO4) at different concentrations (35 wt.% to 65 wt.%) was performed to obtain the nanocellulose. The extracted nanocellulose were characterized by the transmission electron microscope (TEM), atomic force microscope (AFM), Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The produced nanocellulose exhibited rod-like shaped cellulose nanocrystals (CNCs), however, the CNCs structure and crystallinity depended on the H2SO4concentration. It was revealed that the higher H2SO4concentration led to the shorter CNCs lengths. In addition, the crystallinity was generally found to increase with increasing acid concentration treatments but slightly reduce at 65 wt.% of H2SO4.

Immobilisation of yeasts on oak chips or cellulose powder for use in bottle-fermented sparkling wine

Sparkling wine production comprises two successive fermentations performed by Sacharomyces cerevisiae strains. This research aimed to: develop yeast immobilisation processes on two wine-compatible supports; study the effects of yeast type (IOC 18–2007 and 55A) and the immobilisation support type (oak chips and cellulose powder) on the fermentation kinetics, the deposition rate of lees and the volatile composition of the finished sparkling wine; compare the fermentation parameters of the wines inoculated with immobilised or non-immobilised cells. Proper immobilisation of yeast on oak chips and cellulose powder was demonstrated by electron microscopy. Total sugar consumption occurred in under 60 days in all bottles, regardless of the strain used and the way they were inoculated in wine. Deposition of lees was 3-fold faster in the bottles containing immobilised cells than in those with free cells; no addition of adjuvants was necessary. The analysis of the volatile compounds of the finished sparkling wines showed significant differences in the formation of esters, acids, alcohols, aldehydes and lactones according to the yeast and the immobilisation support used. Oak chips were the more appropriate support for yeast immobilisation. No significant differences in the sensorial analysis of the sparkling wines produced by the different strategies were found.

X-ray Diffraction Study of Cellulose Powders and Their Hydrogels. Computer modeling of the Atomic Structure

Cellulose powders from flax fiber and deciduous wood and hydrogels regenerated from DMA/LiCl solutions of them were studied using x-ray diffraction. Structural characteristics were calculated. Three-dimensional models of atomic positions in the short-range order of amorphous hydrogels were constructed. It was found that flax cellulose was characterized by a higher degree of crystallinity and larger transverse cross section and monofilament length than deciduous cellulose. Super-swelled and lyophilized hydrogels from the cellulose solutions gave diffuse diffraction patterns characteristic of amorphous materials. The calculated coordination-sphere radii for lyophilized hydrogels corresponded to analogous data for cellulose II. Differences in the coordination numbers were due to structural differences in the short-range order. The distribution of atoms in the short-range ordered region was modeled using molecular dynamics and corresponded to a disordered cellulose II cluster with dimensions along the crystallographic axes of 2a, 2b, and 5c (15, 16, and 52 A). A cluster consisted of 16 cellulose chains ~52 A in length.

Feasibility of Using Side Products from Chlorine-Dioxide Production to Produce Cellulose Powder

Results from a feasibility study on the use of acidic side products from chlorine-dioxide production to bleach fibrous intermediates in order to produce cellulose powder using acid hydrolysis are presented. Bleached chemical-thermal-mechanical pulps from fir and aspen wood and technical conifer and deciduous celluloses were used as the fibrous intermediates. The effect of the hydrolysis conditions on the morphological and chemical properties of cellulose and lignocellulose powders was studied.