Colloid Mill Research Articles

Comparison of lab-produced asphalt emulsions by manufacturing equipment type

Asphalt emulsions can be produced with colloid mills and high-speed shear mixers, but effects of equipment type on emulsion properties are largely unknown. The study objective was to assess the impact of different manufacturing equipments on emulsion properties. Particle size, viscosity, residue, sieve and storage stability properties were observed after production on three emulsion manufacturing devices. For each device, three emulsions were manufactured by three operator pairs. Median particle size was as small as 2.0 microns on recirculating and in-line equipment, but only 5.3 on high-speed shear mixer. Recirculating equipment also produced emulsion with better storage stability than high-speed shear mixer and in-line equipment. In-line manufactured emulsions had the highest viscosity while the shear-mixed emulsion viscosity was below specification. Sieve was significantly affected by the operator. These results demonstrate that emulsions produced by different laboratory equipment are not identical, and caution must be exercised when comparing and manufacturing lab-produced emulsions.

Tough and highly conductive deep eutectic solvent-based gel electrolyte strengthened by high aspect ratio of hemp lignocellulosic nanofiber

Flexible electronic sensing and energy storage technology impose heightened demands on the mechanical and stable properties of gel electrolyte materials. Lignocellulosic nanofiber (LCNF) present a promising avenue for improving the properties of electrolyte networks and mechanical strength. In this study, LCNF derived from hemp fibers was prepared using lactic acid/choline chloride deep eutectic solvent (DES) through a combination of cooking and colloid mill mechanical treatment to achieve nanocellulose with a high aspect ratio and uniform dimensions. The outcomes demonstrated that LCNF, a width of below 20 nm and a length of over 5 μm, can be effectively produced through the DES cooking pretreatment in conjunction with colloid mill mechanical treatment. Meanwhile, DES lignin possessed a purity of ∼90 % and was obtained as a by-product. Subsequently, the as-prepared LCNF was integrated as a nanofiller into gel electrolyte. Ag-L NPs/LCNF/DES/PAA exhibited dense porous structures and showcased exceptional properties, including a high conductivity exceeding 10 mS/cm and remarkable adhesion strength surpassing 100 KPa. The presence of LCNF allowed Ag-L NPs/LCNF/DES/PAA to achieve strains above 1000 % and compression properties over 1000 KPa. The supercapacitor based on this assembly had a high specific capacitance of 271 F g−1 at 0.5 A g−1), along with an impressive capacity retention rate reaching ∼100 % after 3000 cycles. This investigation offers valuable insights into the utilization of lignocellulosic multi-component approaches in the development of flexible electronic devices.

Development and Evaluation of a Fermented Pistachio-Based Beverage Obtained by Colloidal Mill.

The aim of the present study was to develop a fermented pistachio beverage as a plant-based alternative to milk-based drinks. For this purpose, a colloidal mill was used to finely grind and homogenize the pistachios to obtain a homogeneous consistency and prevent sedimentation. In addition, lactic acid bacteria fermentation was used to develop unique flavours and characteristics in the final product and to achieve microbiological stability for up to 30 days of storage a 4 °C. The formulated beverages were evaluated for chemical-physical characteristics (pH, organic acid production, and fructose, sucrose, and glucose content), nutritional profile (proximate composition, amino acid and GABA content), and volatile organic composition by HS-SPME-GC/MS analysis. The pistachio-based beverages were characterized by a good source of protein, fat, fiber, and minerals (mainly K and P). The colloidal mill contributed to creating a homogeneous texture and to making the nutrients readily available to the starter microorganisms, which reached concentrations above 108 ufc/mL in the final products. The beverages were characterized by pronounced acidity and some by the presence of acetoin and 2,3-butanedione, volatile components associated with a yogurt- or kefir-like aroma. This innovative approach provides an alternative to traditional milk-based beverages and highlights the role of LAB in the development of nutritious and attractive plant-based beverages.

Improvement in Storage Stability and Physicochemical Properties of Whole-Grain Highland Barley Pulp Prepared by a Novel Industry-Scale Microfluidizer System in Comparison with Colloid Milling.

The aim of this study was to assess the advantages of an industry-scale microfluidizer system (ISMS) to prepare whole-grain highland barley pulp (WHBP) compared with colloid milling. Storage stability was evaluated by particle size, gravity separation stability, and rheological properties, as well as the microstructure observation by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLMS). The results showed that colloid milling failed to effectively homogenize the material, while ISMS sample surfaces were compact and smooth at higher pressures according to visual observation and SEM. The Turbiscan stability index of WHBP by ISMS was much lower as a result of colloid milling, demonstrating ISMS can improve WHBP stability. WHBP by colloid milling displayed a three-peak particle size distribution pattern, while a single-peak pattern was evident after ISMS treatment. A higher shear rate decreased the apparent viscosity, suggesting that WHBP was a shear-thinning fluid. According to CLMS, ISMS can successfully improve homogenization by disrupting the structures of oil bodies, proteins, and starches. The WHBP prepared by ISMS exhibited a higher β-glucan level than that prepared by colloid milling, and showed a significant increase in β-glucan level with ISMS pressure. These findings indicate that using ISMS to produce WHBP is viable for enhancing its storage stability and nutritional value.

Droplet size dependency and spatial heterogeneity of lipid oxidation in whey protein isolate-stabilized emulsions

Spatiotemporal assessment of lipid and protein oxidation is key for understanding quality deterioration in emulsified food products containing polyunsaturated fatty acids. In this work, we first mechanistically validated the use of the lipid oxidation-sensitive fluorophore BODIPY 665/676 as a semi-quantitative marker for local peroxyl radical formation. Next, we assessed the impact of microfluidic and colloid mill emulsification (respectively producing mono- and polydisperse droplets) on local protein and lipid oxidation kinetics in whey protein isolate (WPI)-stabilized emulsions. We further used BODIPY 581/591 C11 and CAMPO-AFDye 647 as colocalisation markers for lipid and protein oxidation. The polydisperse emulsions showed an inverse relation between droplet size and lipid oxidation rate. Further, we observed less protein and lipid oxidation occurring in similar sized droplets in monodisperse emulsions. This observation was linked to more heterogeneous protein packing at the droplet surface during colloid mill emulsification, resulting in larger inter-droplet heterogeneity in both protein and lipid oxidation. Our findings indicate the critical roles of emulsification methods and droplet sizes in understanding and managing lipid oxidation.

Study of High-Temperature Rheological Properties of Emulsified Asphalt Residues

The residue of emulsified asphalt is its final state when it becomes part of an asphalt mixture. Therefore, the mechanical properties of the residue have a significant impact on the performance of emulsified asphalt mixtures. Dynamic shear rheological tests and fluorescence microscopy were conducted to explore the effects of emulsification and aging on the rheological properties and micro-morphology of emulsified asphalt residue. The results of both the temperature sweep and multiple stress creep recovery tests indicated that the emulsification of the asphalt had different effects on the rheological properties of the base asphalt and the styrene-butadiene-styrene (SBS)-modified asphalt. For the base asphalt, emulsification increases the complex shear modulus by about 5% and reduces irrecoverable creep flexibility by 30%. However, the physical grinding effect of the colloid mill during the emulsification process could destroy the internal spatial network structure of SBS, leading to a reduction in the complex shear modulus by about 5% and a 10% increase in irrecoverable creep flexibility. This phenomenon is similar to the aging of SBS-modified asphalt, which, in turn, leads to a decline in the performance of emulsified SBS-modified asphalt residues.

Combining colloid milling and twin screw pressing for oleosome extraction

Oleosomes are oil droplets abundant in oilseeds that can be extracted together with proteins for use in emulsion-like foods and can be used as natural, ready emulsions as alternatives to dairy and fat-based products. To make optimal use of the raw material, we look at simultaneous extraction of oleosomes and proteins from rapeseed. The combined approach of colloid milling and twin screw pressing resulted in a higher yield of oleosomes (70 % w/w) when compared to twin screw press alone (54 % w/w), which may be due to extensive cell wall disruption caused by colloid mill processing, as evidenced by SEM imaging. The protein yield remained constant irrespective of the degree of cell wall disruption (50 % w/w). In conclusion, combining the colloid mill and twin screw press is a straightforward way for the extraction of oleosome and proteins from rapeseeds for food application.

The emulsifying performance of brewers' spent grains treated by colloid milling

The sustainable production of food ingredients can be achieved by utilising waste streams, but it is difficult to isolate pure components from a heterogeneous matrix. In this work, brewers' spent grains (BSG), which is a by-product from the brewing industry, was mildly treated with a colloid mill and its emulsifying ability was evaluated. The milled samples contained 26–32% protein and 52–62% fibre and were generally smaller than 10 μm. In its soluble fraction, a small amount of surface-active proteins was present and reduced oil-water interfacial tension by 35%. Emulsions prepared with the milled BSG and its insoluble particles were stable against coalescence for 10 days, with respective droplet sizes of 40 μm and 25 μm. The presence of fibres caused droplet flocculation but also helped to promote network formation. Our results suggest that obtaining pure components may not be necessary for emulsification purposes, especially for the case of particle-stabilised emulsions. Industrial relevanceIndustrial by-products from food processing are generated in large quantities and typically discarded due to their recalcitrant nature. Yet, there is more that can be exploited from this waste stream including proteins and fibres. Separation of these components in their purified form would require harsh methods that are not environmentally sustainable. This study provided insights into the use of a mild and scalable process that can produce functionally active dispersions that are of interest in the preparation of emulsions.

Interpreting the “twice gelation” mechanism of a novel egg-based yoghurt through the dynamics of rheology, microstructure, and intermolecular forces

In this paper, we interpreted the “twice gelation” mechanism of egg-based yoghurt through the integrated multidimensional dynamic change analysis of rheology, microstructure, and intermolecular forces. The results showed that during the first gelation stage (i.e., thermal gelation), egg proteins underwent heat denaturation and formed crosslinks, with the main intermolecular forces involved in gel formation being disulfide bonds (∼84%). After homogenization by the colloid mill, the heat-induced gel transformed into a smooth, viscous fluid state, which subsequently turned into a weak gel as the pH continuously decreased under the effect of lactic acid bacteria fermentation. In the second gelation stage (i.e., acid gelation), the proportion of hydrophobic interactions increased from ∼12% to ∼49%, whereas the proportion of disulfide bonds decreased from ∼74% to ∼45%, indicating that hydrophobic interactions played a crucial role in the second gelation, while disulfide bonds still showed great importance in stabilizing the gel structure, although their percentage decreased significantly. In summary, egg proteins form a hard gel by heating, and this heat-induced gel has the ability to gel twice after homogenization, making it possible to form egg-based yoghurt with a fine texture and good taste under the action of lactic acid bacteria fermentation.

One-pot strategy to enhance nanofibrillation and esterification of cellulose using ternary deep eutectic solvent

Establishing green and efficient method for the nanofibrillation and modification of cellulose is the foundation to prepare the cellulose functional material. Herein, we provided a "one-pot " strategy to achieve the high-efficiency nanofibrillation and esterification of nanocellulose using the ternary deep eutectic solvents (DESs). The widths of cellulose nanofiber (CNF) with 18.9 ± 2 nm were successfully prepared by swelling with maleic acid/choline chloride (MA/ChCl) DES at 100 °C for 3 h, followed by mechanical colloid milling. The corresponding acid anhydrides maleic anhydrides (MAH) was added to form MAH/MA/ChCl DES for enhanced esterification of nanocellulose. As a result, the nanocellulose achieved a high degree of substitution (DS) of up to 0.84. The feasibility of "one-pot " strategy based on other ternary DESs (acetic anhydride/acetic acid/choline chloride (AAH/AA/ChCl), succinic anhydride/succinic acid/choline chloride (SAH/SA/ChCl) as representative) was further studied to fibrillate and esterify nanofibers, demonstrating it is an efficient method for the nanofibrillation and modification of cellulose.

Structure Characteristics and Removal Behavior of the Deposited Carbon on Ni-Al2O3 Catalyst for CO2 Reforming of CH4

Four catalysts were prepared in our previous work using the solution combustion method, incipient-wetness impregnation method, colloid mill circulating impregnation method, and hydrothermal-precipitation method, respectively, labeled as SCM, IMP, T310, and HTP. And the performance (stability) of the four catalysts for CO2 reforming of CH4 was investigated at 800 °C. In this paper, the composition and structure characteristics of the deposited carbon on the above four catalysts were tested through TEM, Raman, TPH, and TG-DTG technologies. The results showed that filamentous carbon was the primary type of carbon deposition on the catalysts, and a large amount of accumulated carbon would block the catalyst pores, affecting the catalytic performance. The carbon deposited on the catalyst prepared using the hydrothermal-precipitation method calcined at 800 °C exhibited a high degree of graphitization, and the proportion of graphitized carbon was considerable, which is harmful to the stability of the catalyst. The decarburization temperature of the deposited carbon on the four catalysts was mainly in the range of 500–700 °C. Using the Coats–Redfern model, as the reaction order was set as 1, 2, 3, 4, and 5, the decarburization activation energy ranged between 50 and 80 kJ/mol.

Linking particle morphology and functionality of colloid-milled dietary fibre concentrates from various plant sources

Dietary Fibre Concentrates (DFCs) can be obtained from various agro-food by-products. The origin of DFCs is hypothesized to influence their functional properties and thus potential applications. The study aimed to investigate the functional behaviour of DFCs from six sources upon colloid milling. The functionality of DFCs obtained from asparagus and orange peel showed significant improvement after colloid milling, while less effect for other sources (i.e., barley bran, licorice residue, pea fibres and corn cob). All six DFCs comprised a high proportion of insoluble fibre, while the total fibre content varies from 47.12 to 86.24 g/100 g. Total fibre content affected the functional properties, whereas the DFC particle morphology appeared to have the largest effect for the six DFCs. Fibre particles obtained from asparagus and orange peel DFCs showed increased degree of fibrousness and particle elongation after colloid milling, led to the significant improvement of functionality. Conversely, fibre particles derived from other sources exhibit denser micro-structures that are unaffected by colloid milling. We therefore conclude that the change in morphological properties of DFCs particles could be linked to the functional behaviour of colloid-milled samples.

The Enhancement of Overall Performance of Lubricating Grease by Adding Layered Double Hydroxides

In this work, MgAl-layered double hydroxides (LDH) were synthesized by co-precipitation method using a colloid mill and characterized by XRD and SEM. It was found that the environmentally friendly LDHs had greater performance than the traditional antioxidant. By adding LDHs into large electric shovel grease (GRK-A) in open-pit coal mine, the service lifetime of grease was extended by 20%. With the increase in LDH addition, the grease sample attains greater activation energy, and the thermal oxidation and decomposition resistance become stronger. Comparing the energy storage modulus and flow transition index at different temperatures, adding the right amount of LDHs needs close attention for the system oxidation resistance and viscoelasticity. For the electric shovel grease, the best oxidation resistance and rheological properties can be achieved by adding 2% of LDHs. The rheological viscosity–temperature curves show that the grease samples with different ratios of solid LDHs have better low-temperature properties than the mine grease. This work outlines a simple method for creating an environmentally sustainable lubricant additive with the use of LDH. LDH serves as a novel inorganic antioxidant additive that is optimal for open gear lubrication and sliding friction.

3D printability of sturgeon paste as affected by colloid milling

Colloid milling was used to prepare sturgeon (SG) paste, and the changes of physicochemical properties of SG myofibrillar proteins (MfPs) were characterized as they were affected by different grinding treatments (0, 1, 2, 3, 4, 5 cycles). The results showed that moderate grinding (3 cycles) promoted the structural changes (secondary and tertiary structures) in MfPs that were favorable for surimi gel formation, which led to improved gel strength and functional properties in SG surimi products. More specifically, in SG MfPs treated with 3 grinding cycles, with significant transition of α-helixes to β-sheets, and expansion of the tertiary structure. The shear thinning behavior of the SG paste produced via proper colloid milling imparted good fluidity in it during extrusion-based 3D printing, which improved its printability and could facilitate development of 3D printed SG surimi products.

Defect-Rich CoFe-Layered Double Hydroxides as Superior Peroxidase-like Nanozymes for the Detection of Ascorbic Acid.

The development of artificial enzymes with superior catalytic properties to natural enzymes has been a long-standing goal of chemists. Herein, defect-rich CoFe-layered double hydroxides (d-CoFe-LDHs) nanosheets are developed and used as superior peroxidase-like nanozymes for the detection of ascorbic acid (AA). The d-CoFe-LDHs with an average thickness of ∼3 nm and a lateral size of ∼20 nm are synthesized through rapid nucleation in a colloid mill, which exhibited abundant unsaturated sites (oxygen vacancies and cobalt vacancies). Impressively, d-CoFe-LDHs exhibited excellent peroxidase-mimicking performance with strong substrate affinity and robustness in a wide pH range. Density functional theory calculations show that d-CoFe-LDHs have lower H2O2 adsorption energy, which promotes the decomposition of H2O2, thereby improving the catalytic activity. The chromogenic system of d-CoFe-LDHs and 3,3',5,5'-tetramethylbenzidine can be used to accurately detect the content of AA, and the detection limit is about 3.6 μM. This study opens up a new approach for the construction of highly active defective LDH peroxidases for the detection of biomolecules.

Pharmaceutical development of micro and nanocrystals of a poorly water-soluble drug: Dissolution rate enhancement of praziquantel

Different strategies have been applied to address the low aqueous solubility of drugs, since this property affects their oral absorption. In this context, particle size reduction approach can increase solubility and dissolution rate of drugs, so enhancing their bioavailability. Praziquantel (PZQ) is still the drug of choice for schistosomiasis control, however, the drug formulation is challenging considering its low aqueous solubility, which is a limiting step for its oral absorption. To prepare microcrystals (MCs) and nanocrystals (NCs) applying wet milling methods, to increase the dissolution profile of racemate praziquantel. PZQ suspensions were prepared in a colloid mill for obtaining MCs and in a pearl mill for obtaining NCs. The suspensions were characterized by multiple light scattering, laser diffraction and dynamic light scattering. Then, the suspensions were spray dried. The characterization of dry powders was carried out by different techniques such as Fourier transform infrared spectroscopy, X-ray powder diffraction, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, laser diffraction and powder dissolution. To evaluate the effectiveness of the preparations, the infected mice were treated with 400 mg/kg of the compounds and analyzed. After process optimization, the most promising samples had a d50 value of 6.84 μm and an average diameter of 346.2 nm, respectively. After drying, the d50 values obtained for MC5 and NC5 were similar (11.77 μm and 8.76 μm, respectively). All powder samples presented enhanced dissolution compared to PZQ raw material, and there was a 13-fold increase in dissolution profiles by MC5. All the tested compounds provided a significant reduction in the parasitic load (above 70%) and changes in the oogram profile. The in vivo results suggest the ability of the MC and NC formulations to maintain the effectiveness of the PZQ compounds on the adult worms of S. mansoni, exerting even better activity on the eggs adhered to the tissue of the mammalian host. A scalable process was used to obtain MC and NC of PZQ with significantly improved dissolution in comparison to the pure drug. Moreover, the produced formulations were able to increase the ability of the PZQ to act on the parasite eggs trapped in the tissue and could potentially induce an early improvement of granulomatous lesions. The developed systems show promising aspects as candidate to be incorporated in a solid dosage form, with lower API concentration and even better drug activity.

Effect of Flaxseed Addition on the Quality and Storage Stability of Sesame Paste.

The flaxseed-sesame paste (FSP) was prepared by mixing the heat-treated flaxseed and sesame seeds in different proportions and grinding them in a colloid mill to obtain a FSP. In this study, flaxseed was added to sesame paste (SP) at different addition to assess its effect on the rheological properties, textural properties, and particle size. The effect of flaxseed addition on lipid oxidation and volatile aldehydes and ketones during storage of SP was investigated by accelerated oxidation experiments (63°C, 60 days). Notably, the addition of all different additions of flaxseed increased the linolenic acid content, and also enhanced the hardness, cohesiveness, and viscosity of SP. However, it increased the rate of lipid oxidation in SP during storage, mainly in the form of higher acid value (AV) and malondialdehyde (MDA) content. The content of volatile aldehydes and ketones from lipid oxidation increased significantly with storage time. It was found by using cluster analysis that mixing flaxseed with SP at a ratio of 20 g/100 g had little effect on its storage stability, the sample had a higher overall quality than the addition of 40 g/100 g flaxseed, and its linolenic acid content was 18.7 times higher than that of the SP. Collectively, the results indicated that the addition of flaxseed at an appropriate proportion might be a feasible way to prepare the functional formulated SP.

Laboratory design and evaluation of a functional color micro-surfacing with synthetic resin-based binder

ABSTRACT In this study light color asphalt with different resins, extract oil, and modifier usage was subjected to mechanical stirring and penetration, softening point, and ductility tests. The colloid mill prepared light color emulsified asphalt, and the emulsifying effect of different emulsifier usage on light color asphalt, waterborne epoxy resin (WER) usage and fiber-reinforced material influence color micro-surfacing modification were studied. The results showed that the light color asphalt prepared by Resin b has better low temperature performance and the optimum dose of SBS modifier content is 5% ∼ 6%. The influence degree on the mixing time of micro-surfacing is in the following order: cement > light color emulsified asphalt > water > mineral powder. The optimal emulsified asphalt consumption is 10.5%, and the corresponding pre-wetting water consumption is 6.6% through the one-hour wet track abrasion test (WTAT) and loaded wheel test (LWT). The results showed that WER could significantly enhance the wear resistance, water damage resistance, and durability of color micro-surfacing mixture but has adverse effects on the low-temperature performance of the mixture. Polypropylene fiber has better anti-wear performance, while basalt fiber has better anti-rutting performance.

MODIFICATION OF BITUMEN WITH RECYCLED PLASTICS FROM WASTE MATERIALS

It is proposed to use plastic waste as bitumen modifiers with a special emphasis on recycled plastics. The potential use for improving the characteristics of bitumen and durability of roads is being considered. For the preparation of modified bitumen, it was used the BND 100/130 bitumen produced by LLP "JV CASPI BITUMEN" (Kazakhstan). Polymer household waste based on plastic bottles was used as objects of the research. Polymer waste was obtained by mechanical recycling. The main physical and mechanical characteristics of the modified bitumen were determined after routine tests, penetration and plasticity, softening temperature, Fraas brittleness temperature and microscopic analysis. The morphology of the modified bitumen was studied using scanning electron microscopy. An original formulation of the polymer-bitumen binder with improved performance characteristics compared to petroleum bitumen has been developed. The introduction of used polymer waste as a modifier does not require the installation of an additional homogenizer (colloidal mill), and there is no need to introduce a plasticizer to achieve the desired uniformity of the system and required by the Kazakhstan standard PMB 40 and PMB 90. Thanks to the use of this technological solution, it is possible to level the problem of disposal of household polymer waste with the polymer-bitumen binder production. This polymer modifier is characterized by low cost of its production. The advantage of the used polymer additive is the stage of polymer preparation - the process of joint chemical destruction of secondary polyethylene terephthalate in the presence of a highly elastic styrene-butadiene-styrene polymer to inhibit the delamination of polymer components in bitumen, due to which the problem of manufacturing high-quality homogenization of the product is solved.

The effect of colloid milling on the microstructure and functional properties of asparagus dietary fibre concentrates

Dietary Fibre Concentrate (DFC) derived from vegetables side streams obtained during industrial processing can be exploited as a fibre-rich food ingredient. In this study, colloid milling was investigated as an environmentally-friendly physical method to improve the functional properties of asparagus DFC. Functional properties such as swelling capacity, water holding capacity and emulsifying activity of asparagus DFC showed significant improvement after intensive colloid milling. Scanning electron microscopic analysis showed that the microstructure of the freeze-dried samples consisted of an intertwined three-dimensional network containing highly branched micro-fibres. The fibre suspensions showed shear thinning behaviour, which could be explained by the network formation. An additional thermal pre-treatment appeared to further enhance the positive effect of colloid milling on the functional properties of DFC. This study shows that colloid milling is an effective process to functionalize asparagus DFC, which could broaden its application in fibre-rich food products.