Colloid Mill Research Articles

The Influence of Comminuting Methods on the Structure, Morphology, and Calcium Release of Chicken Bones.

This work aimed at assessing the influence of comminuting methods, including colloid mill, planetary ball mill and dynamic high-pressure microfluidization on the chemical composition, particle properties, morphology and calcium release of chicken bone. The results showed that planetary ball mill and dynamic high-pressure microfluidization could reduce the particle size of bone powder, and the particle size of sample treated by dynamic high-pressure microfluidization reached 446 nm. Chicken bone particles were negatively charged, and the absolute value of zeta potential was significantly reduced after milling treatments. Furthermore, X-ray diffraction and Fourier-transform infrared spectroscopy (FTIR) analysis indicated that the planetary ball mill and dynamic high-pressure microfluidization processes presented no significant effect on the internal chemical structure of bone particles. Compared with the other groups, samples treated by dynamic high-pressure microfluidization released more calcium ions, which was related to the significant effects on surface calcium composition and reducing particle size. Therefore, dynamic high-pressure microfluidization has a great potential in the processing of bone-derived products, particularly for the design and development of bone-derived product with high calcium bioaccessibility.

Rheology, ignition, and combustion performance of coal-water slurries: Influence of sequence and methods of mixing

This paper presents the results obtained from a comprehensive study of how the conditions and methods of preparing three-component fuel slurries affect their ignition, combustion, emissions, as well as viscosity and static stability. The data obtained for slurry fuels based on bituminous coal and water with added waste hydrocarbon oil and wood biomass as well as a slurry based on coal slime. A tubular muffle furnace was used for combustion at 700–900 °C. The influence of the mixing conditions of the components on the ignition and combustion behavior was moderate. It was established that surfactants should not be added to composite slurry fuels at the final stage of component mixing. To provide more uniform burnout of a blend with wood biomass, the latter should first be mixed with water and then the coal component should be added. Iterative mixing can provide a 10–15% improvement of ignition and burnout characteristics. To obtain a more homogeneous and stable blend, it is advisable to use a cavitator (colloid mill) rather than a homogenizer or a magnetic stirrer. Based on a set of parameters (viscosity, stability, cost, ignition and combustion characteristics), a dimensionless efficiency indicator was calculated using Weighted Sum Method. The calculated values of the relative efficiency indicator of the fuel blends based on coal dust ranged from 0.67 to 0.73. The relative efficiency of a slurry was found to increase by 25–30% when coal dust is replaced by coal slime due to the economic parameter.

Microstructural Properties of Polymer-Modified Bitumen Emulsion-Cement Composites Considering the Production Method

The present study investigated the effect of the polymer-modified bitumen emulsion production method on the properties of cement-polymer emulsion paste. Modified emulsions were made using three methods, including comilling, soap prebatching, and postblending. During comilling, water, acid, styrene-butadiene rubber polymer, emulsifier, and bitumen were added simultaneously to the colloidal mill. In soap prebatching first water, acid and emulsifier were mixed to produce the soap. Then, polymer was added to the soap, and the resulting compound is added simultaneously to a colloidal mill with the bitumen. During postblending, water, acid, and emulsifier were first mixed. Then, this mixture and bitumen were added to the colloidal mill. Next, polymer was added to obtain the polymer-modified bitumen. Portland cement was added to the produced polymer-modified emulsions and cured at 40°C for 72 h. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy tests were performed on the samples to investigate the weight distribution, dispersion of elements, and hydration rate of cement particles. Using the X-ray diffraction test, cement hydration products were identified, and the particle dispersion of these products was investigated. Moreover, the microstructure, adhesion, and elastic modulus of the samples were examined using atomic force microscopy. Based on the results and analyses, the highest homogeneity in particles distribution due to hydration of cement and the highest elastic modulus in cement samples were related to those made by postblending, whereas the soap prebatching methods resulted in the highest adhesion in cemented samples.

Effects of Colloid Milling and Hot-Water Pretreatment on Physical Properties and Enzymatic Digestibility of Oak Wood

A two-step process using colloid milling (CM) and hot water (HW) treatment was evaluated for its ability to improve xylose recovery and the enzymatic digestibility of oak wood. In the first step, CM pretreatment was applied at a milling (feeding) speed of 100 mL/min with four different milling times (3, 6, 9, and 12 h), and the enzymatic digestibility and physical properties of each substrate were measured. In the second-step, the HW pretreatment was applied to enhance the enzymatic digestibility and xylan recovery at various reaction severities (Log R0) from 2.07 to 4.43 using 12 h colloid-milled (CM-treated) oak wood. Compared with untreated oak wood, CM not only significantly disrupted the structure of oak wood but also increased its Brunauer–Emmett–Teller surface area (42-fold) and pore volume (28-fold). The crystallinity of two-step-treated oak wood was decreased to 34.8, while the enzymatic digestibility of 12 h CM-treated oak wood was increased to 58.1% at enzyme loading of 30 filter paper units (FPU)/g glucan for 96 h. After HW treatment of CM-treated oak wood at Log R0 = 3.83, 80.7% of xylan recovery yield and 91.1% of enzymatic digestibility (with 15 FPU/g glucan at 96 h) was obtained, which was 84.2% higher than the enzymatic digestibility of untreated oak wood (6.9%).

Lignocellulose nanofiber/polylactic acid (LCNF/PLA) composite with internal lignin for enhanced performance as 3D printable filament

The use of lignocellulose materials to prepare reinforced composites for 3D printing is promising. In this study, lignocellulose nanofibers (LCNFs) with different lignin contents (0.2–8.5%) were prepared and compounded with polylactic acid (PLA) for fabricating a 3D printable filament. The internal lignin of LCNFs served as an adhesive for improving the interfacial compatibility of LCNF/PLA composites. Alkali lignin (AL), as an external lignin, was used as a control sample. LCNFs, with a high yield of 85%, a diameter of less than 100 nm, and a length of several microns, were prepared by the swelling of glycerol and 0.64% (w/w) sulfuric acid and colloid mill grinding. Complexation of cellulose nanofiber (CNF) and LCNF with PLA can enhance the mechanical strength of PLA composites. Specifically, the flexural strength of the CNF/PLA composite was increased from 92.7 MPa to 151.2 MPa by combining 10% CNF (without lignin) with PLA. The flexural strength of LCNF/PLA composite with internal lignin content of 3.7% (0.37% of the total mass) was increased from 151.2 MPa to 234.5 MPa, which is 153.0% higher than that of pure PLA. However, external AL had an adverse influence on the mechanical strength of the AL/CNF/PLA composites. In addition, the 3D printable filament prepared using the LCNF/PLA composite exhibited good thermal stability, which was suitable for common fused deposition modeling (FDM) 3D printers. Various 3D printing materials, such as cake, egg, ball, bowl, dumbbell and strip shaped products, were designed and prepared by LCNF/PLA composites.

Removal of Stone Cells From Guava Nectar

Several methods have been investigated for reducing the grittiness of guava nectar caused by the presence of stone cells. Of the several methods tried, which included nitration, centrifugation, cyclone separation, and particle-size reduction using a colloid mill and a stone mill, centrifugation and treatment in the stone mill proved to be the best. When the nectars are centrifuged in a solid-basket centrifugal, the grittiness was completely eliminated, since the stone cells responsible for this grittiness are separated during the process. Nectars of similar quality were prepared by size reduction of the stone-cell particles in a stone or mustard mill. A comparison of both methods showed that higher yields of nectar are obtained when the stone mill is used to disintegrate the stone cell, but some discoloration results when pink-colored fruit is treated thus. Treatment in the stone mill also results in a higher loss of vitamin C when compared to the loss that results when the nectars are centrifuged.

Effect of Processing Parameters on Properties of Bitumen Emulsions

Bitumen emulsions are special type of paving binder materials used in road construction industry due to its environmentally friendly approach, cost efficiency and less energy consumption compared to other conventional bitumen binders. Despite so many benefits, the use of bitumen emulsions is still limited in many regions due to difficulties faced in its emulsification process. Controlling several process parameters are needed during formulation while achieving the sufficient storage stability and viscosity. Therefore, this study was conducted to investigate the effect of different processing parameters on the properties of bitumen emulsions in terms of storage stability and viscosity. The 80/100 grade bitumen was emulsified through colloid mill, considering different pH values and emulsifier concentrations as processing parameters during emulsification process. The results indicate that the storage stability has improved significantly with increased concentration of emulsifier whereas high acidic system in terms of pH level has also substantially enhanced storage stability at lower level of emulsifier concentration. In addition, the viscosity of bitumen emulsions has also been affected by the emulsifier concentration and higher amount of emulsifier resulted in higher values of viscosity at lower pH level. The data achieved through this investigation can be further used to study the effect of other formulation parameters on properties of bitumen emulsions.

Old Corrugated Container (OCC) Cardboard Material: An Alternative Source for Obtaining Microfibrillated Cellulose

ABSTRACT Nowadays, there is a growing interest in lignocellulosic nanoscale materials produced from alternative recycled sources because of their attractive physical, chemical, and mechanical properties, as well as their ecological contribution. In this work, MFC preparation through mechanical fibrillation using lignocellulosic fibers from OCC cardboard was investigated. Also, the effect of alkaline pulping and bleaching treatments was also evaluated in a comparative study. The fibers’ and microfibers’ morphology were determined by light microscopy, SEM, and TEM. The structural and chemical characterizations of the samples were inspected by intrinsic viscosity, FTIR, and XRD. The chemical treatment improved effects on the kappa number, morphology, and crystallinity of the lignocellulosic materials. The fibrillation process in a colloidal mill was possible using unbleached OCC fibers, contributing to a more efficient and environmentally friendly procedure. The OCC is a promising alternative source to produce microfibrillated cellulose with suitable properties and high potential in renewable material applications.

Freeze-thaw stability of emulsions made with native and enzymatically modified egg yolk fractions

Frozen storage of food emulsions can increase their tenability and create possible applications in frozen food products. However, coalescence and phase separation can occur during freezing/thawing. In order to assess options for mitigating freeze/thaw-destabilization, egg yolk's emulsifying functionality in the form of whole egg yolk and its granula and plasma fractions was investigated. The fractions were enzymatically pretreated (phospholipase A2) and their emulsifying functionalities were assessed in dependence of pH, salinity, freezing velocity and frozen storage time with oil droplet size and phase separation as measures. Mayonnaise-type oil in water emulsions of sunflower oil were prepared at pH 3, 4 and 6.5 with a salt content of 0.15 and 0.55 M NaCl with a colloid mill. The emulsions were frozen to −20 °C with varying freezing rates and stored up to 24 h. Egg yolk and plasma stabilized emulsions showed higher freeze/thaw stabilities than granule stabilized emulsions. Enzymatic treatment increased the stability of emulsions prepared with egg yolk and granula, but decreased the stability for plasma stabilized emulsions. The destabilization increased with longer frozen storage time. Very slow or fast freezing velocity resulted in higher destabilization effects than an intermediate freezing rate at low salt content. Increasing salinity from 0.15 to 0.55 M NaCl as well as increasing pH from 3 to 6.5 resulted in more stable emulsions and highest destabilization at the highest freezing rate.

Effects of lead time and manufacturing methods applied for polymer-modified bitumen emulsion (PMBE) on microsurfacing performance

The modified microsurfacing mix design procedure for polymer-modified bitumen emulsion (PMBE) is introduced in this study under the influence of emulsifiers, lead time and through application of SBR latex polymer injection techniques, including the co-milling, soap pre-batching and post-blending procedures. The bitumen tests have shown that the type of emulsifier and the residence time of the bitumen emulsion in the colloidal mill, as well as the manufacturing process all affect the PMBE properties. Therefore, each type of emulsifier had different properties; especially the co-milling method of diluted bitumen emulsion had the highest performance in terms of physical and rheological tests due to the higher residence time of the bitumen emulsion in the colloidal mill which enhances bitumen properties. According to the results of the microsurfacing tests, the vertical deformation resistance, moisture damage resistance and bleeding potential were improved by 46.55%, 25.7% and 15.2%, respectively, through modifying in the co-milling method.

Evaluation and identification of parameters affecting the penetration of emulsion bitumen on aggregates

ABSTRACT More penetration of the prime coat increases the stabilisation thickness of the sub-asphalt layer and makes it more difficult for water to penetrate. Therefore, the purpose of this study is to identify the effective parameters on the penetration of Cationic Emulsion Bitumen (CEB) and investigate their effects. Short and long-term penetration tests are used. For better evaluation, two types of silica and limestone aggregates are selected in dry and wet conditions. To better compare the results of penetration, the penetration of MC250 cutback bitumen was also measured. The results show that among the identified parameters, the maximum penetration increase is influenced by the time of penetration, the material of aggregates, aggregate humidity, type of prime coat, kerosene percentage, and colloid mill speed which is equal to emulsifier percentage and the percentage of pure bitumen. Also, the least effect is observed for increasing soap temperature. Another result is that the CEB penetration in limestone aggregates is inappropriate in all cases. However, the penetration of CEB in silica aggregates in almost all cases provides minimum requirement so that the moisture being most effective to increase it. The value of MC250 penetration in limestone aggregates is only appropriate for wet and long-term conditions.

Functionality of MC88- and MPC85-Enriched Skim Milk: Impact of Shear Conditions in Rotor/Stator Systems and High-Pressure Homogenizers on Powder Solubility and Rennet Gelation Behavior.

Milk protein concentrate (MPC) and micellar casein (MC) powders are commonly used to increase the protein concentration of cheese milk. However, highly-concentrated milk protein powders are challenging in terms of solubility. The research question was whether and how incompletely dissolved agglomerates affect the protein functionality in terms of rennet gelation behavior. For the experiments, skim milk was enriched with either MC88 or MPC85 to a casein concentration of 4.5% (w/w) and sheared on a laboratory and pilot scale in rotor/stator systems (colloid mill and shear pump, respectively) and high-pressure homogenizers. The assessment criteria were on the one hand particle sizes as a function of shear rate, and on the other hand, the rennet gelation properties meaning gelling time, gel strength, structure loss upon deformation, and serum loss. Furthermore, the casein, whey protein, and casein macropeptide (CMP) recovery in the sweet whey was determined to evaluate the shear-, and hence, the particle size-dependent protein accessibility. We showed that insufficient powder rehydration prolongs the rennet gelation time, leading to softer, weaker gels, and to lower amounts of CMP and whey protein in the sweet whey.

ИССЛЕДОВАНИЕ МЕТОДОВ ПОДГОТОВКИ ОРГАНОСОДЕРЖАЩИХ СЕЛЬСКОХОЗЯЙСТВЕННЫХ ОТХОДОВ ДЛЯ ИХ ДАЛЬНЕЙШЕЙ ПЕРЕРАБОТКИ В СВЕРХКРИТИЧЕСКОЙ ВОДНОЙ СРЕДЕ

The problem of waste disposal is always acute in all areas of production activity, especially for the agro-industrial complex. Supercritical water oxidation is the most environmentally friendly method for processing organic waste and persistent organic pollutants. In the process of recycling and disposal, along with the harmfulness, one of the main indicators is the initial state of the waste and its suitability for different disposal technologies. (Research purpose) The research purpose is in choosing and justifying the most energy-efficient method of grinding, taking into account the fact that the organ-containing waste under study (buckwheat husk, sunflower, rice) is soft, elastic and fibrous materials. (Materials and methods) The crushing of organic waste to prepare it for further processing was carried out by different methods in roller, ball, knife and colloid mills. A set of sieves with square cells according to GOST 2715-75, a drying cabinet SHS-80-01 SPU, analytical scales Acculab ALC-210d4 (weighing error of no more than 0.5 percent of the sample weight) were used to evaluate the fractional composition of the obtained material. (Results and discussion) At a concentration of 100 grams of husk per 1 liter of water after 30 minutes of wet grinding, the passage of particles through the sieve is 87.1 percent. The article presents the advantage of wet grinding in a knife mill, reveals mathematical dependencies that allow predicting the grinding process to obtain the product of the required dispersion. (Conclusions) The grinding of organ-containing waste in a knife mill by wet grinding is the most optimal technology for preparing this waste for further processing in a supercritical water environment. The obtained mathematical dependencies allow us to predict the grinding process.

Contribution of lignin in esterified lignocellulose nanofibers (LCNFs) prepared by deep eutectic solvent treatment to the interface compatibility of LCNF/PLA composites

It is important to improve the interface compatibility between lignocelluloses (LCs) and biodegradable polylactic acid (PLA) for the preparation of strong composite materials. In the current study, esterified lignocellulose nanofibers (LCNFs) with high yield were prepared from LCs with different lignin contents (0.83–17.45 %) by swelling with a lactic acid/choline chloride deep eutectic solvent (LA/ChCl DES) at 100 ℃ for 3 h followed by mechanical colloid milling. Esterification occurred along with nanofibrillation of the LCs to obtain LCNFs having ester bonds with diameters mostly less than 100 nm. Lignin remained in the LCNFs with various contents. Uniform LCNF/PLA composites were prepared by a direct blending method. Lignin in the esterified LCNFs acted as an interface adhesive and played a key role in increasing the LCNFs interface compatibility with PLA, as well as strengthening the mechanical properties of the composites. The optimized flexural properties of the composites reached a maximum value of 204.5 MPa when 20 % LCNF (containing 10.92 % lignin) was added, which was 120.6 % higher than that of pure PLA. The prepared high-strength biodegradable composites have broad application prospects and great potential to replace non-degradable plastics.

Effects of lutein particle size in embedding emulsions on encapsulation efficiency, storage stability, and dissolution rate of microencapsules through spray drying

Microencapsulation is an effective technique for maintaining stability of labile bioactive components. However, as an indispensable process prior to microencapsulation, the effects of emulsion preparation on microencapsulated products are often overlooked. In this study, three industrialized comminution techniques (wet media milling, high pressure homogenization, and colloid milling method) were used to manufacture four lutein-loaded primary emulsions with different lutein particle size (from 238.2 nm to 2.2 μm). Subsequently, lutein-loaded emulsions were microencapsulated through spray drying. The physicochemical properties, encapsulation efficiency, storage stability, and dissolution rate of lutein microencapsulated powder (LMPs) were examined to evaluate the effects of different emulsions on the quality of LMPs. Results indicated that the encapsulation efficiency and storage stability of LMPs decreased as the lutein particle size in emulsions increased. The LMP with smallest lutein particles possessed highest encapsulation efficiency (97.9%) and storage stability (plateau value of 89.44 and 78.85% at 25 °C and 40 °C). In vitro release study showed that apparent solubility and dissolution rate of LMPs containing nano-sized particle were significantly increased, compared with micron-sized LMPs and physical mixture. Our study suggested that preparing the emulsion containing nano-size lutein particles is critical for improving shelf life and oral bioavailability of this bioactive product.

Scale-up synthesis of monolayer layered double hydroxide nanosheets via separate nucleation and aging steps method for efficient CO2 photoreduction

Photocatalytic CO2 reduction is one of the most promising ways to solve the energy crisis and the greenhouse effect. Among the abundant products (CO, HCOOH, CH3OH, CH4, etc), it is difficult to reduce CO2 through 8 electrons to CH4. Monolayer layered double hydroxides (denote as LDHs) have drawn wide attention and interest due to the abundant defects and unique electronic structure. However, the monolayer LDHs can be obtained mainly in the lab scale, which seriously hindered their practical large-scale industrial application. Herein, a facile approach to synthesize monolayer LDHs was developed by modifying the industry colloid mill reactor through the addition of a small amount of layer growth inhibitor formamide using separate nucleation and aging steps (SNAS) method. The obtained monolayer LDH nanosheets by SNAS possessed a thickness of ~1 nm, with uniform lateral size and abundant defects, which exhibited superior activity in CO2 photoreduction with 81.75% selectivity to CH4 while inhibiting H2 selectivity <3% under visible light. This method is universal to different LDHs and can be used for large-scale preparation, which lays the foundation for the industrial production of monolayer LDHs.

Alkaline Fractionation and Subsequent Production of Nano-Structured Silica and Cellulose Nano-Fibrils for the Comprehensive Utilization of Rice Husk

The parameters of the alkaline fractionation process were investigated and optimized using a statistical analysis method to simultaneously remove hemicellulose and ash from rice husk (RH) concomitantly. After the alkaline fractionation process, the residual solid contained high cellulose, and the recovery yield of hemicellulose was enhanced in the fractionated liquid hydrolyzate. The hemicellulosic sugar recovery yield (71.6%), de-ashing yield (&gt;99%), and lignin removal (&gt;80%) were obtained at the reaction conditions of 150 °C of temperature, 40 min of reaction time, and 6% (w/v) of NaOH concentration. Subsequently, nano-structured silica was synthesized using black liquor obtained as a by-product of this fractionation process. For the production of nano-structured silica, it was observed that the pH of a black liquor and the heat treatment temperature significantly influenced the textural properties of silica product. In addition, the two-stage bleaching of solid residue followed by colloid milling for the production of high value-added CNF with was attempted. As a result, in addition to 119 g of fermentable sugar, 143 g of high-purity (&gt;98%) silica with a surface area of 328 m2g−1 and 273.1 g of high-functional CNF with cellulose content of 80.1% were simultaneously obtained from 1000 g of RH.

Validating the textural characteristics of soft fish-based paste through International Dysphagia Diet Standardisation Initiative recommended tests.

One in every twelve people worldwide suffers from dysphagia that affects the swallowing mechanism and some patients require a special texture-modified food for their sustenance. Fish is a great source of nutrients and proteins, however the commercially dysphagia diet made from fish is limited. This study investigated the textural characteristics of a soft fish paste produced from steamed grass carp fillet with different the water addition, grinding cycles and ratio of starch with the mixture of steamed fillet and water, following International Dysphagia Diet Standardisation Initiative (IDDSI) guidelines and other instruments. The water addition and particle size affected the physical properties, and the starch had a certain masking effect on fishy odor. The mixture of steamed fish fillets and water (91:9 wt/wt) was ground in a colloid mill for 3 cycles. The fish paste was then sterilized by adding sugar, salt, and starch in the mixture (ratios of 0.5:100, 0.5:100, and 0.6:100, wt/wt, respectively) and mixing well. The paste conformed to Level 4-pureed and extremely thick of IDDSI framework. The fish paste product had a light fishy odor that was acceptable to sensory specialists.

Preparation of cellulose nanocrystals and their application in reinforcing viscose filaments

Rod-like cellulose nanocrystals (CNCs) were mechanically prepared from microcrystalline cellulose by colloid milling, and then the CNCs were used to reinforce rayon filament yarn by way of viscose blending and wet spinning. Compared with ordinary viscose filaments, the viscose filament yarn enhanced by CNCs had higher crystallinity, dry and wet tensile strengths, and better humidity release. When the addition amount of CNCs reached 1 wt%, the crystallinity of the viscose filament was obviously improved, and as a result, the wet and dry tensile strengths increased by 14% and 24%, respectively, showing excellent mechanical properties. The research work in this paper has a certain reference significance to improve the mechanical performance of viscose filaments, and more importantly, the CNC preparation process used in the work is simple and environmentally friendly.

The advantages of using polymer-bituminous concentrate for the production of polymer-bituminous binders

Construction of road surfaces with an extended service life, as well as the transition to methods of volumetric and functional design of asphalt concrete mixtures, leads to the need for the use of polymer-bituminous binders, as bitumen without polymer modifiers does not provide the required physical and mechanical characteristics and durability. Traditional PBB production technologies involve the use of complex technological processes and equipment. In addition, existing technological features lead to a significant decrease in the quality of the resulting polymer-bituminous binder. In this paper, we consider the possibility of obtaining PBB with high physical and mechanical parameters by using the PBC modifier (polymer-bituminous concentrate). The modifier under study is a polymer dispersed in an oil base and stabilized with active components. When added to bitumen, a colloid mill and complex processes of preparation and maturation of the binder are not required. Experiments have shown that the resulting binder has the characteristics of PBB, in particular, an extended temperature range of plasticity, elasticity and resistance to cyclic loads. At the same time, gentle heating modes provide increased resistance to aging during the preparation of asphalt concrete mixture and its operation. The ease of use of this modifier makes it possible to obtain PBB with a wide range of characteristics that correspond to the operating conditions.