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The colloid-chemical properties of humic acids (HAs) were studied depending on the mechanochemical modification of their structure. An increase in the amount of acidic ionogenic groups and hydrophilic fragments in the composition of modified HAs facilitated a decrease in the excess energy of surface molecules. In an alkaline solution, two types of colloids characterized by a decrease in the energy of adsorption and the constant of adsorption equilibrium were formed as the concentration of HAs was increased. [ABSTRACT FROM AUTHOR]

In the context of a diet transition from animal protein to plant protein, both for sustainable and healthy scopes, innovative plant-based foods are being developing. A combination with milk proteins has been proposed as a strategy to overcome the scarce functional and sensorial properties of plant proteins. Based on this mixture were designed several colloidal systems such as suspensions, gels, emulsions, and foams which can be found in many food products. This review aims to give profound scientific insights on the challenges and opportunities of developing such binary systems which could soon open a new market category in the food industry. The recent trends in the formulation of each colloidal system, as well as their limits and advantages are here considered. Lastly, new approaches to improve the coexistence of both milk and plant proteins and how they affect the sensorial profile of food products are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 –aNCNT nanocomposites exhibited enhanced dye degradation despite poor colloidal stability. • NTiO 2 –aNCNT nanocomposites formed stable colloids but exhibited poor photocatalytic efficiency. • 100 % decolorization and 78 % mineralization of RR120 by TiO 2 –aNCNT nanocomposites observed under sunlight irradiation. • Significantly reduced charge transfer resistance and increased electron transfer kinetics achieved by aNCNTs. • Optoelectrical properties dominated the photocatalytic process. The correlation of photocatalytic efficiency of titania–amorphous (nitrogen doped) carbon nanotubes (TiO 2 –a(N)CNT) nanocomposites with colloidal and optoelectrical properties was investigated. TiO 2 –aNCNT and TiO 2 –aCNT exhibited narrow zeta potential variation, high polydispersity index, and large agglomerate sizes across the pH range 1–8. Despite their poor colloidal stability, TiO 2 –aNCNT exhibited superior degradation efficiency for high molecular weight reactive dyes, RR 120 and Remazol brilliant blue (RBB) with 55 mg.L−1 of RR 120 mineralized under solar irradiation. The photocatalytic performance for TiO 2 –aNCNT and TiO 2 –aCNT correlated with the respective energy band gaps 3.01 and 3.14 eV (respectively) and Ubarch tailing energies. Cyclic voltammetry showed a narrow peak-to-peak separation (Δ E p) of 200.7 V (vs Ag/AgCl) for TiO 2 –aNCNT thus confirming enhanced electron transfer kinetics. Electron impedance spectroscopy confirmed low charge transfer resistance for TiO 2 –aNCNT. Herein, it is demonstrated that optoelectrical properties are superior to colloidal stability in driving photocatalytic reactions. [ABSTRACT FROM AUTHOR]

In the context of a diet transition from animal protein to plant protein, both for sustainable and healthy scopes, innovative plant-based foods are being developing. A combination with milk proteins has been proposed as a strategy to overcome the scarce functional and sensorial properties of plant proteins. Based on this mixture were designed several colloidal systems such as suspensions, gels, emulsions, and foams which can be found in many food products. This review aims to give profound scientific insights on the challenges and opportunities of developing such binary systems which could soon open a new market category in the food industry. The recent trends in the formulation of each colloidal system, as well as their limits and advantages are here considered. Lastly, new approaches to improve the coexistence of both milk and plant proteins and how they affect the sensorial profile of food products are discussed.

Antibiotics occur ubiquitously in natural aquatic and sediment environments, and they share the same transport routes with many other colloid particles such as minerals and oxides. However, their potential colloidal interactions are poorly understood. This work is a rapid communication of the colloidal behavior of different minerals and organic colloids (< 5 µm), i.e., haematite, goethite, bentonite, kaolinite, biochar, lateritic-, kaolinitic- and illitic soil clays, with the effects of antibiotics, i.e., oxytetracycline (OTC), sulfapyridine (SPD) and ciprofloxacin (CPX) with the purpose of providing a robust transportability prediction for these constituents. The zeta potential (ζ) and hydrodynamic size (d h) of antibiotic-mineral colloid suspensions were tracked over a pH range from ∼3 to ∼9, and then coupled with colloidal dynamic data provided by test tube experiments. The antibiotics used were found to vary ζ of colloids to different extents, hence they modified colloidal dynamics of colloids. Specifically, CPX with the concentration range from 10 to 40 mg L−1 resulted in drastic increases in ζ and counteracted the dispersion of colloids (especially lateritic soil clay), while OTC and SPD at the concentration ranges of 2.5–20 mg L−1 and 10–40 mg L−1 (respectively) showed minor effects. This suggests that the selective sorption of colloids for cationic antibiotics may induce dispersive changes, result in a delayed transport of cationic antibiotics and eventually reroute the transport of colloids. The observed phenomena for these used colloids and antibiotics can empirically exemplify what are happening in natural aquatic and sediment environments; and the role of mineral colloids as either carriers or barriers for the possible terrestrial-to-ocean transports of antibiotics worldwide needs to be highlighted. [Display omitted] [ABSTRACT FROM AUTHOR]

To provide theoretical support for the digestive properties of soup, nutrition concentration, colloidal properties, and structures were analyzed in colloidal nanoparticles (CNPs) from the lamb bone soup group (BS) and the lamb meat soup group (MS). BS-CNPs had higher protein and triglyceride concentrations than MS-CNPs. After 3 h stewing, the rate of protein leaching from CNPs in both groups slowed down, with the triglyceride being largest at 3 h with 2.05 mmol/L in BS-CNPs and 1.44 mmol/L in MS-CNPs. Colloidal properties results showed that as the stewing time increased, particle size and derived count rate increased in both groups. The maximum particle size was observed at 5 h with 268 nm of BS-CNPs and 488 nm of MS-CNPs. Fourier transform infrared spectroscopy reflected that O-H, N-H and C-H absorption peaks were blue-shifted with time, but valence bonds in both groups were the same. Circular dichroism spectroscopy revealed that the α-helix and β-turn of both groups decreased while β-sheet and random coil increased with time. Scanning electron microscope showed that CNPs became larger with time, and BS-CNPs resembled cubes while MS-CNPs were spherical. In conclusion, stewing time influenced the physicochemical properties of CNPs significantly (P<0.05) with 3 h stewing soup time recommended. • The particle size of colloidal nanoparticles increased with stewing time. • Colloidal nanoparticles of bone soup were more stable than those of meat soup. • 3 h was the best stewing time for lamb soup. [ABSTRACT FROM AUTHOR]

The incorporation of straw into soil has been encouraged as an alternative straw‐disposal strategy to the on‐site burning that occurs in many paddy regions. However, this practice may lead to changes in the colloidal properties of soil clays that potentially intensify clay and nutrient losses. This study aimed to demonstrate the effect of engineered microsized straw powder on the colloidal properties of two soil clays, that is, illitic and kaolinitic soil clays. Dynamic light scattering was coupled with the test tube method to evaluate time‐resolved changes in the particle size, zeta potential and dispersibility for the suspensions of straw powder and its mixtures with illitic and kaolinitic soil clays. Data from kinetic experiments over a time span of 20 days revealed that straw powder remarkably increased the dispersibility of soil clays. It was found that straw particles carried negative charges; thus, the introduction of straw powder into the clay suspensions increased the number of negative charges in the system, thereby increasing internal repulsive forces and eventually favouring clay dispersion. Moreover, certain mutual processes, that is, the biodegradation and dissolution of phytoliths (silica in straw), resulted in the release of dissolved organic matter and silicon, which aggravated clay dispersibility. In addition to the "traditional" awareness of the impacts of straw incorporation, for example, creating toxic, reduced environments or increasing CH4 emissions, the changes in the colloidal properties of soil clays should also be highlighted. We propose that the incorporation of straw requires additional solutions for the prevention of clay loss. Highlights: Straw powder was examined for possible effect on colloidal properties of soil claysIt was found that straw particles carried negative chargesIntroduction of straw powder increase repulsive forces and favor clay dispersionMicroorganism, B. amyloliquefaciens, enhances the effect of straw powder [ABSTRACT FROM AUTHOR]

This review article discusses humic substances – specific organic compounds, which are the substantial part of the bioenergy matrix of the food chains of living creatures and the essence of the exchange interaction of those media. The dead organisms (mostly plants) are transformed into humic substances. A prerequisite for creating the monograph was a steady interest in humic substances from humus specialists (soil scientists, agricultural chemists, coal chemists, etc.) and biologists, physicians, and workers in agriculture, forestry, and communal services. At the same time, monographs are quite rare in the literature, where humic substances are described quite fully. Based on our experience in studying humic substances, we have attempted to characterize humic substances comprehensively. Collecting disparate information and analyzing it made it possible to obtain a more or less holistic view of such a unique natural object as humic substances. Much attention is paid to the colloidal properties of these specific compounds. We must not forget that humic substances are a necessary and mandatory component of all metabolic processes in the biosphere. [ABSTRACT FROM AUTHOR]

BACKGROUND Flavor loss is a common problem when manufacturing apple juice and is closely related to the properties of the colloidal pectin particles in cloudy juice. The flavor changes and particle properties of three varieties of apple juice ('Ralls', 'Golden Delicious' and 'Fuji') during processing were investigated. RESULTS: Compared with manually pressed juice, juice made by industrial pulping and filtration contained larger particles, resulting in the 'sweet and sour' taste of the juice being relatively weak and the diversity of aromas narrower, as determined by E‐nose analysis. Pulping and filtration, however, released some important flavor esters, such as butyl butyrate, hexyl‐2‐methyl butyrate, and hexyl butyrate. The transformation of volatile compounds during apple juice processing was closely related to the apple cultivar but, in all three varieties, the content of 1‐hexanal and (E)‐2‐hexenal in the juice gradually decreased during processing. Pectinase treatment reduced the colloid particle size and increased the ζ‐potential of the juice, resulting in better uniformity and stability, as well as increasing the content of nonanal. After pasteurization, the colloidal particles tended to aggregate and the ζ‐potential decreased. Many volatile compounds decreased in concentration or disappeared after heat treatment. CONCLUSION: The flavor and colloidal properties of cloudy apple juice changed markedly during processing and the effect of each processing step was different. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Variability in the efficacy, safety, and quality of probiotic formulations depends on many factors, including process conditions used by manufacturers. Developing reliable analytical tools is therefore essential to quickly monitor manufacturing differences in probiotic samples for their quality assessment. Here, multi-strain probiotics from two production sites and countries were investigated by proteomics and physico-chemistry approaches in relation to the protective effect on gut barrier. Proteomic analyses showed differences in protein abundances, identities, and origins of two series of VSL#3 samples from different sites. Even though both formulations were qualitatively similar in thermal and colloidal profiles, significant differences were quantitatively observed in terms of maximum decomposition temperature Tmax (p < 0.05) and phase transition temperature Tm (p < 0.01). Such variability in physical and biochemical features impacts on probiotic functionalities and translates into a differential modulation of gut permeability in mice. Physico-chemical scans provide coherent data with proteomics and represent a new tool for time and cost effective quality control of probiotic-based products. [ABSTRACT FROM AUTHOR]

• Complexes of hyaluronic acid with water-soluble chitosan derivatives formed colloidal nanoparticles. • Metastable quenched nanoparticles consisted from the secondary aggregates of primary polyelectrolyte complexes. • Scattering from the nanoparticles corresponded to Debye-Bueche model revealing their disordered heterogeneous structure. Polysaccharide-based polyelectrolyte complexes (PECs) are of great interest for the development of drug delivery systems, as they are easily prepared and exhibit a wide range of colloidal properties. The water-soluble diethylaminoethyl chitosan (DEAE-CS) was synthesized with various degrees of substitution (DS), ranging from 26 to 113%. Analysis of the substitution pattern of DEAE-CS by different NMR techniques revealed N - and O -substitution, as well as quaternization of the tertiary amino group of the DEAE substituent; the fraction of quaternary amino groups increased with the DS. Unlike the tertiary amino groups, the quaternary amino groups did not support increases in the ζ-potential of DEAE-CS with the DS and the complexation with hyaluronic acid (HA). The influence of the PEC composition, DS of DEAE-CS, and mixing order on the size and polydispersity of PEC nanoparticles was investigated by dynamic and static light scattering. Internal disordered heterogeneous PEC nanoparticles were formed by the aggregates of several primary PECs. Disordered and structurally heterogeneous spherical complexes were formed (R g / R h = 1.0 ± 0.3). The obtained PECs were metastable and their properties were influenced by mixing order. The high molecular weight component (HA), being a minor component, was more exposed on the surface than was the low molecular weight DEAE-CS. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles (IONPs) are suitable materials for contrast enhancement in magnetic resonance imaging (MRI). Their potential clinical applications range from diagnosis to therapy and follow-up treatments. However, a deeper understanding of the interaction between IONPs, culture media and cells is necessary for expanding the application of this technology to different types of cancer therapies. To achieve new insights of these interactions, a set of IONPs were prepared with the same inorganic core and five distinct coatings, to study their aggregation and interactions in different physiological media, as well as their cell labelling efficiency. Then, a second set of IONPs, with six different core sizes and the same coating, were used to study how the core size affects cell labelling and MRI in vitro. Here, IONPs suspended in biological media experience a partial removal of the coating and adhesion of molecules. The FBS concentration alters the labelling of all types of IONPs and hydrodynamic sizes ≥ 300 nm provide the greatest labelling using the centrifugation-mediated internalization (CMI). The best contrast for MRI results requires a core size range between 12–14 nm coated with dimercaptosuccinic acid (DMSA) producing R2* values of 393.7 s−1 and 428.3 s−1, respectively. These findings will help to bring IONPs as negative contrast agents into clinical settings.

A rapid and exact method for the determination of the colloidal properties of tannin solutions following microwave irradiation was developed and validated using a modified zetasizer. The accuracy and feasibility online detection compared with the conventional method were characterized by the particle size and zeta potential of the tannin solutions treated with microwave irradiation using the optimized conditions, including the tannin concentration, microwave radiation time, and temperature. The results showed that the values determined by the online method presented a linear relationship at a tannin concentration of 4 g/L, microwave times of 30-90 min, and temperatures from 25 to 40 °C. These values were essentially unchanged using conventional detection. In addition, the online method is feasible for both hydrolyzable and condensed tannins. Ten parallel measurements had relatively small standard deviations, showing that the precision was within acceptable limits. Therefore, the online method is appropriate for the characterization of tannin colloidal properties treated with microwave radiation which may have practical applications. [ABSTRACT FROM AUTHOR]

Semi-continuous emulsion polymerization of vinyl acetate and dioctyl maleate (VAc/DOM) (60/40, w/ w) was carried out with pre-emulsion feeding using potassium persulfate as an initiator. The influence of emulsifier type and its initial ratio were studied and the mixture of non-ionic emulsifiers; 30 and 10 mol ethoxylated nonylphenol (NP30 and NP10) at a ratio of 50/50 ( w/ w) provided better pre-emulsion and polymerization stability, and also final latex stability. In addition, two series of experiments were conducted to determine the effect of initiator and reactive surfactant, oligomeric N-methylol acrylamide (o-NMA) amount in the initial reactor charge on the latex properties. By increasing the initial initiator amount from 10 to 50 wt%, the average particle size of the latexes decreased from 203 to 143 nm. As expected, the amount of initiator strongly affected the particle charge and the highest zeta potential value was obtained when 50 wt% of the initiator was initially present in the reactor, showing the increased latex stability. On the other hand, it was detected that the colloidal properties of the copolymer latexes were significantly affected by the change of initial charge of o-NMA. The o-NMA amount exceeding 50 wt% caused coagulation. When all o-NMA was initially fed, the highest viscosity value, 9878 cP; lowest zeta potential value, − 5 mV; and the highest surface tension value, 37.5 mN m, were obtained. Consequently, the change in the initial charge of emulsifier, initiator, and reactive surfactant has played an important role on the colloidal stability of VAc/DOM latexes. [ABSTRACT FROM AUTHOR]

Background and hypothesis: Humic acid (HA) is of considerable environmental significance, being a major component of soil, as well as being considered for application in other technological areas. However, its structure and colloidal properties continue to be the subject of debate, largely owing to its molecular complexity and association with other humic substances and mineral matter. As a class, HA is considered to comprise supramolecular assemblies of heterogeneous species, and herein we consider a simple route for the separation of some HA sub-fractions. Experiments: A commercial HA sample from Sigma-Aldrich has been fractionated into two soluble ( S1 , S2 ) and two insoluble ( I1 , I2 ) fractions by successive dissolution in deionized water at near-neutral pH. These sub-fractions have been characterized by solution and solid-state approaches. Findings: Using this simple approach, the HA has been shown to contain non-covalently bonded species with different polarity and water solubility. The soluble and insoluble fractions have very different chemical structures, as revealed particularly by their solid-state properties ( 13 C NMR and IR spectroscopy, and TGA); in particular, S1 and S2 are characterized by higher carbonyl and aromatic contents, compared with I1 and I2 . As shown by solution SAXS measurements and AFM, the soluble fractions behave as hydrophilic colloidal aggregates of at least 50 nm diameter. [ABSTRACT FROM AUTHOR]

The low solubility of wheat gluten limits its accessibility. This work aimed to study the impact of ultrasonic pretreatments on the gelation of wheat gluten. The pretreatments included ultrasound combined with alkali, urea, Na 2 SO 3 , with or without the addition of transglutaminase (TGase). The gel strength of wheat gluten was 287 g/cm 2 after treatment with Na 2 SO 3 /ultrasound/TGase. The free sulfhydryl and disulfide bond content was significantly affected by ultrasound treatment. After treatments including TGase crosslinking, the molecular weight of wheat gluten complexes became larger. The network formed by the wheat gluten was transformed into a dense and homogenous structure after the pretreatment with Na 2 SO 3 /ultrasound/TGase. The content of random coil of wheat gluten increased. The gelation of wheat gluten could also be significantly enhanced by Na 2 SO 3 /ultrasound treatment followed by TGase treatment. Using physical and chemical pretreatments to allow TGase to enhance the gelation of wheat gluten may increase its uses as a food additive. [ABSTRACT FROM AUTHOR]

Waterborne few-layer graphene oxide/poly(methyl methacrylate-co-butyl acrylate), FLGO/poly(MMA-co-BuA), nanocomposites were synthesized by in situ emulsion polymerization. The FLGO nanosheets used in this study was prepared by modified Hummers method and followed by an exfoliation process. The obtained FLGO and both latex and film forms of the nanocomposites were characterized in detail. It was found that the interactions between FLGO and copolymer matrix, and therefore the nanocomposite properties including colloidal, morphological, thermal and mechanical were directly dependent on the amount of FLGO in the composite composition. With the addition of 1% FLGO by weight (relative to the monomer), hydrodynamic diameters of the polymer particles in latex increased from 39.7 nm to 92.0 nm and moreover zeta potential value of this nanocomposite latex reached to −85 mV. Also, the nanocomposite film of this nanocomposite showed significant improvements in glass transition temperature (T g ), thermal degradation temperatures and Young’s modulus values, comparing with other nanocomposites. The analysis results confirmed that the FLGO was chemically interacted with the poly(MMA-co-BuA), and also finely dispersed in the matrix. [ABSTRACT FROM AUTHOR]

High-concentration protein formulation (HCPF) is a term that is used to describe protein formulations, mostly monoclonal antibody (mAb) drugs, at high protein concentration. The concentration is rarely defined, with typical ranges varying between 50 and 150 mg/ml for mAbs. The term HCPF is meant to include and express specific solution properties of formulations that are prone to appear at high protein concentrations such as high viscosity, high opalescence, phase separation, gel formation or the increased propensity for protein particle formation. Thus the term HCPF can be understood as a descriptor of protein formulations, usually at high protein (monoclonal antibody) concentrations, which have specific solution, stability and colloidal properties that differ from formulations at low protein concentration (e.g. at 10 mg/ml). The current paper highlights in brief the development challenges that might occur for high-concentration protein/monoclonal antibody formulations. In particular, the maximum concentration regimes achievable in HCPF remained unclear. Based on geometrical considerations involving packing of monoclonal antibodies in a lattice we map out a maximum concentration range that might be theoretically achievable. Different geometrical assumptions and packing models are compared and their relevance is critically discussed, in particular concerning the influence of the physicochemical properties of the monoclonal antibodies on their solubility, which is neglected in the simple geometrical model. According to our estimates, monoclonal antibody concentration above 500 mg/ml will be very challenging to achieve. Our results have implications for setting up realistic drug product development strategies and for preparing convincing drug target product profiles for development. [ABSTRACT FROM AUTHOR]

Within the general context of nanomedicine, drug delivery systems based on polymers have sparked a rapidly growing interest and raised many efforts to tackle various diseases, among which cancer. Polyester-based nanoparticulate drug delivery systems, including polymer-drug conjugates and amphiphilic block copolymers, represent a major class with promising outcomes, especially for those derived from poly(3-hydroxybutyrate) (PHB). This review describes recent advances in drug delivery systems designed from the self-assembly of synthetic (co)polymers derived from PHB. The various strategies for the synthesis of PHB-conjugates, PHB/poly(ethylene glycol) (PEG) and other PHB-based copolymers are first summarized. Nanoparticles, micelles, microparticles, and hydrogels elaborated from these (co)polymers following various preparation methods, along with their exploitation in the encapsulation and release of various therapeutic agents, are next detailed. Finally, we discuss the synthetic challenges, drug delivery outlooks, and perspectives of PHB-based drug delivery systems. Engineered nano-scaled materials based on PHB self-assembled systems are thus anticipated to emerge as a valuable platform for original drug delivery systems. [ABSTRACT FROM AUTHOR]

With Trap-Ox Fe-zeolites we intend to develop a novel nanoremediation concept, which is based on in situ trapping of organic contaminants by adsorption and catalytic oxidation in combination with oxidants such as hydrogen peroxide. Within this study, colloidal properties including surface charge and suspension stability as well as mobility in porous media were studied under various conditions for two Trap-Ox Fe-zeolite representatives: Fe-BEA35 and Fe-MFI120. These Fe-zeolites can act as adsorbent for contaminants and as micro-reactors for their catalytic Fenton-like oxidation. Both Fe-zeolites under investigation show remarkable suspension stability in slightly alkaline suspension (pH 8–8.5) without any additional stabilizers, but not in acidic suspensions (pH 5.5). Mobility investigations in columns with clean sand and natural sand suggest high mobility at slightly alkaline conditions. Particle breakthrough through 20 cm sand columns was >75% for the two zeolites when injected as 10 g/L suspensions with a flow velocity of 10 m/d. However, under acidic conditions in natural sediment, a long period of near-total deposition of particles is observed before high breakthrough occurs. The pH dependency is believed to be caused by charge inhomogeneity due to Fe-oxide clusters on the zeolites as well as on the sediment grains. [ABSTRACT FROM AUTHOR]

The temperature, concentration and pH variables influence the aqueous dispersion of the gum properties. In this context, the aims of this research were to characterize the gum obtained from the buriti tree (Mauritia Flexuosa) trunk exudate, as well as to evaluate the colloidal and rheological behavior of the aqueous dispersions of this gum. Thus, the centesimal composition, absolute zeta (Ϛ) potential as a function of pH (1.2 to 4.0), particle size distribution, as well as the rheological properties of the gum at different temperatures (15, 20, 25, 30, and 40 °C) and concentrations (4, 5, 8, and 10% (m/v)) were studied. In addition, the Newton, Power Law, and Herschel-Bulkley models were fitted to the rheological data. Buriti tree gum (BG) was found to have 10.43% moisture, 5.05% ashes, 0.68% lipids, 3.09% proteins, and 80.76% carbohydrate. The aqueous dispersion of the gum (1%) had a Ϛ value of -17.1 mV with a tendency for greater stability at pH < 4 and polydisperse particle size distribution (45 nm to 648.1 nm diameter) with PDI (polydispersity index) of 1. The aqueous dispersion with 4 and 5% gum had typical Newtonian fluid behavior and became pseudoplastic at concentrations of 8 and 10%. The Herschel-Bulkley model had the best fit to the rheological data (r² > 0.99). Gum dispersion viscosity decreased with higher temperature and lower concentration. The activation energy (Ea) value for gum dispersion ranged from 9.07 to 17.35 kJ/mol. [ABSTRACT FROM AUTHOR]

For decades, cellulose nanocrystals (CNCs) have been produced by hydrolyzing the disordered cellulose chains of hierarchical fiber structures. These colloidal particles comprise highly ordered arrays of cellulose chains, impeding the physicochemical modifications of inner crystalline layers, which in turn restrict key colloidal properties, such as dispersion stability, functionalizability and charge, response to external fields, and transportation. Controlled oxidation of fibrils permits the partial disintegration of amorphous cellulose chains while maintaining contact with the crystalline body, yielding Janus-like nanoparticles with a needle-shaped crystalline body sandwiched between two disordered cellulose regions (hairs). We refer to these nanoparticles as hairy cellulose nanocrystalloids (HCNC). The protruding soft biopolymer brushes impart significant modifications to the colloidal properties of cellulose nanocrystals, promoting their functionality, charge, stability, and self-assembly. In this article, we embark on detailing how HCNCs behave more like soft nanoparticles as compared to rigid CNCs, explain their fundamental colloidal aspects, and provide a mechanistic overview on how HCNC may expand the horizon of next generation natural soft materials. [ABSTRACT FROM AUTHOR]

The nanoscale dispersion of rod-like crystal bundles or aggregates of natural palygorskite (PAL) is not only significant in practical application but is also a challenge. In this paper, phytic acid (PA) was introduced during high-pressure homogenization (HPH) process to simultaneously disperse PAL crystal bundles and restrain the re-aggregation of the dispersed nanorods. SEM, TEM, XRD, FTIR and N 2 adsorption–desorption analyses confirmed that the crystal bundles or aggregates of PAL were highly disaggregated and dispersed to individual nanorod with no disruption to the aspect ratio of rods after being homogenized at 30 MPa, and PA molecules are favorable to dispersion and restrain the re-aggregation of nanorods. The nanoscale dispersion of PAL rods increased the BET specific surface area and Zeta potentials, and effectively improved the colloidal properties. The colloidal viscosity of modified PAL was sharply increased by 110.4% (from 1728 mPa·s to 3636 mPa·s) at the optimal dosage of PA (0.1 wt.%) and the homogenization pressure of 30 MPa, and the suspension stability was clearly enhanced by 71%. This simple disaggregation process provides a new industrial approach to produce nanoscale PAL and extend its application in modern industry. [ABSTRACT FROM AUTHOR]

Polymeric nanoparticles have attracted growing attention because of their unique properties and extensive application. In this study, polycaprolactone (PCL) nanoparticles were prepared via double emulsion solvent evaporation-like process using power ultrasound, and the effects of various process parameters on particle size, zeta potential, and morphology were investigated and optimized. Nanoparticles (NPs) were prepared by two-step emulsification process. In the first step, the inner aqueous phase (W) was homogenized with organic phase (PCL in dichloromethane) to obtain primary emulsion. In the second step, the primary emulsion was emulsified with outer aqueous phase (W) containing polyvinyl alcohol (PVA) as stabilizer using power ultrasound, followed by evaporation of solvent which resulted in a particulate suspension at the end. Effects of various parameters like ultrasound exposure time and amplitude, outer aqueous phase volume, PVA concentration, and PCL content were investigated. It has been shown that, by increasing ultrasound exposure time, amplitude, and outer aqueous phase volume, the particle size decreases. Additionally, particle size was also related to amount of PCL and PVA concentration. Spherical NPs with smooth surfaces were observed by scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

The aim of this research was to investigate the effect of polyglycerol polyricinoleate (PGPR) on the stability and colloidal behavior of W/O emulsions, with or without pectin present in the water phase. Stable emulsions containing 30 % water were obtained using 2 % PGPR. When diluted, the size of the droplets formed measured by dynamic light scattering, was inversely proportional with the concentration of PGPR; however, these results were not in agreement with rheology and diffusing wave spectroscopy measurements at higher concentrations of PGPR (>4 %). The discrepancy suggested that compositional changes in inner water phase affected the w/o interface and the physico chemical properties of the emulsions. It was hypothesized that in the presence of pectin less PGPR was needed to form the water droplets. In the absence of pectin, PGPR emulsions were less turbid than when pectin was present in the water phase. In all cases, when the emulsions were further diluted with oil, they showed a hard sphere behavior. These results highlight the importance of studying water in oil emulsions using bulk rheology and light scattering without dilution, as it is possible to better understand differences in their colloidal properties. [ABSTRACT FROM AUTHOR]

Highlights: [•] Treatment at moderate time did not change the colloidal properties of solution. [•] Protein oxidation did not occur but SH ionization enhanced. [•] SDS–PAGE showed that aggregates resulted from covalent and non-covalent bonds. [•] Main components of aggregates were lysozyme, ovalbumin and ovotransferrin. [Copyright &y& Elsevier]

The nanorods of natural palygorskite exist as aggregates or bundles. High-pressure homogenization technology can disaggregate effectively the bundles or aggregates of palygorskite in water. In order to further explore the effect of the dispersion medium on the dispersion efficiency, in this paper, palygorskite was dispersed in ethanol–water mixture with the aid of high-pressure homogenization. The effects of various ethanol/water ratios on the microstructure and colloidal properties of palygorskite were investigated. It was found that the dispersion efficiency of aggregates during the homogenization process was affected as increasing the ethanol/water ratio from 0:10 to 4:6. The introduction of ethanol into the aqueous suspension of palygorskite could weaken the van der Waals forces and hydrogen bonding interaction among rods, and a stable suspension with higher shear stress and shear modulus was obtained at the ethanol/water ratio of 6:4 ( v / v ). [ABSTRACT FROM AUTHOR]

Highlights: [•] Colloidal properties of Ferrihydrite humic acid coprecipitated are investigated. [•] Fe–HA coprecipitate increase in the size and negative charge compare with HA. [•] ξ-Potential measurements revealed a increment of negative charge for Fe–HA at pH 4–8. [•] At neutral alkaline pH the Fe–HA negative charge enhancing colloidal stability. [•] Ferrihydrite–HA coprecipitate could play an important role in the carbon stabilization. [ABSTRACT FROM AUTHOR]

Colloid-sized microplastics (MPs) are ubiquitous in aquatic environments and can share the same transport route together with various crystalline, poorly crystalline and freshly formed iron oxides. However, the colloidal interactions between these colloid constituents are not fully understood. This study was designed to investigate the colloidal properties of polystyrene microplastics (PSMPs) under the influence of haematite, goethite, ferrihydrite and freshly formed Fe oxide (FFFO). Dynamic light scattering was coupled with a test tube method to observe changes in the surface charge and colloidal dynamics of suspensions of PSMPs and Fe oxides. The overall effects on the aggregation of PSMPs are found to decrease in the following order: FFFO > ferrihydrite > goethite > haematite. The effects of these Fe oxides are found to strongly depend on pH. While the crystalline oxides play a dominant role in the acidic environment, poorly crystalline oxides show greater effects on PSMP aggregation in an alkaline environment. Heteroaggregation due to decreasing electrostatic interactions is the major mechanism that governs the colloidal dynamics of PSMPs and Fe oxides. It can be inferred that the copresence of Fe oxides and MPs can delay the transport of MPs or even change the destination for MPs. [Display omitted] • PSMPs carry negative charges and exhibit high mobility in aqueous solution. • Fe oxides show their ability to stimulate aggregation of PSMPs. • Heteroaggregation due to electrostatic interactions is the major mechanism. • Fe oxides and PSMPs can delay the transport of PSMPs. [ABSTRACT FROM AUTHOR]

Highlights: [•] Industrial softwood kraft lignin has been modified using Mannich reaction. [•] NMR was used to clarify reaction mechanism and to quantify amine groups introduced. [•] Phenolation pre-treatment was performed to increase lignin reactivity. [•] Products possess higher molecular masses and highly increased dispersibilities. [•] Products form excellent colloidal suspensions with many potential applications. [ABSTRACT FROM AUTHOR]

Abstract: Chitosan is among the most abundant biopolymers on earth and has been either used or exhibited potential in a wide variety of industrial and biomedical applications. With the advancement of materials technologies, chitosan has been chemically modified to self-assemble into nanoarchitectures that are usable in advanced biomedical applications, such as drug nanocarriers, macroscopic injectables, tissue-engineering scaffolds, and nanoimaging agents. Colloidal amphiphilically modified chitosan (AMC) is a relatively recent material receiving increased attention with numerous publications addressing the medical advantages of specific systems. To date, many reviews have focused on the synthesis and biomedical properties of chitosan-based biomaterials, but a comprehensive study focusing on the colloidal properties of AMC in relation to biomedical performance appears to be lacking. This review provides a survey of the field, critically reviewing the colloidal properties and biomedical performance of AMC systems, such as nanoparticle drug delivery systems and macroscopic medical devices. Finally, the future development, market potential, and clinical implications of these promising colloidal-structured biomaterials are summarised. [Copyright &y& Elsevier]

Abstract: The development of small particles in ion chromatography (IC) is a recent phenomenon. Very few studies are available on packing polymeric particles bearing ionizable functional groups. This study explores the colloidal and rheological properties that govern slurry packing to form high efficiency IC columns. The polymeric substrate used was non-porous 4.4μm sulfonated ethylvinylbenzene–divinylbenzene (1.4mequiv. SO3H/g resin) with 55% crosslink. We developed simple tests optical microscopy and sedimentation tests for predicting the quality of packed columns. The negatively charged particles (zeta potential: −52mV in water) behave like colloids. The influence of counter-ion charge (Al3+, Mg2+, Na+) and ionic strength on column efficiency followed the Schulze–Hardy rule. Highly flocculating slurries give poorly packed columns with N ∼900 whereas under non-agglomerating slurry conditions efficiencies up to N >10,000 can be achieved. A non-agglomerating slurry also shows non-Newtonian behaviour, specifically shear thickening. Packing at lower flow rate (<1mL/min) or higher temperature (>50°C) reduces the shear thickening and produces higher efficiency columns. The packed sulfonated resin column is coated with 72nm quaternary ammonium bearing latex (AS4A) and used in the separation of F−, Cl−, NO2 −, Br−, and NO3 − yielding a reduced plate height of 1.9 under optimum conditions. [Copyright &y& Elsevier]

The effects of pulsed electric fields (PEF) and high-temperature short time (HTST) on the colloidal properties of carrot juice initially after PEF processing and throughout storage period were studied. Compared with HTST treatments, PEF treatments have less effect on the colloidal properties, such as cloud stability, zeta potential, viscosity and particle size distribution (PSD). Pectin methyl esterase (PME) could influence the colloidal properties of carrot juice by de-esterification of the pectin. In the present work, PME activity was reduced significantly as electric-field strength (from 15 to 30 kV cm−1) and treatment time (from 100 to 800 μs) increased. The results also showed that the emergency of a new peak in PSD of samples occurred when the electric intensity exceeded 30 kV cm−1. Images of transmission electron microscopy showed that particles slightly gathered after PEF treatment. However, under HTST treated, these smaller particles aggregated into net-like structures that further gathered larger particles. At the micro level, both PEF treated (30 kV cm−1, 800μs) and HTST treated kept good stability for more than 1 month. [ABSTRACT FROM AUTHOR]

Abstract: We report on the synthesis of magnetic iron oxide particles; study of the particles’ formation was undertaken to investigate conditions of precipitation in order to apply it efficiently to cellulose fibre coating procedures. Synthesis of magnetic particles was performed, comprised of variations of molar concentrations of precursor solutions as well as different addition protocols of reactants into the reaction system. This allowed us to investigate the formation of iron oxide particles from different starting points. Following the synthesis, an evaluation of particles’ formation in different stages of synthesis procedure i.e. at different pH values and analysis of particles’ properties was carried out. Structural properties (crystallinity, size of the single magnetite crystals), their magnetic and colloidal properties were correlated with the synthesis procedure used. Procedure with controlled addition of ammonium hydroxide solution into a solution of precursor iron salts results in magnetic particles with largest crystallite size and the most intense X-ray diffraction patterns. Size and crystallinity of formed particles are also dependent upon the molar concentrations of Fe2+ and Fe3+ ions. Highest values of saturation magnetization are again exhibited by particles, produced with controlled addition of catalyst into a solution of precursor, a consequence of their ordered structure, which also favourably influences their colloidal properties when dispersed in an aqueous-based ferrofluid. Gained insight of the presented synthesis study will prove useful when in situ precipitation of magnetic iron oxide particles will be used for the preparation of magnetic solid cellulose substrates, since it will allow for the optimal adjustment of process conditions. [Copyright &y& Elsevier]

Introduction. Many desirable properties make cloudy fruit juice widely produced according to consumer acceptance. The pulp of mango (Mangifera indica L.), a good source of carbohydrates and water, has many uses including the production of juice. Nowadays, the use of food enzymes has become widespread in the juice industry for various reasons. However, the application of enzymes has not yet been tested in the context of the production of cloudy mango juice, except for the stabilization of nectars. Thus, the aim of our study was to examine and optimize some parameters involved in the enzymatic production of cloudy mango juice. Materials and methods. To achieve our objective, we used Response Surface Methodology (RSM) by combining five factors: time (30–50 min), temperature (35–55 °C), pH 4–5.5, Pectinexr Ultra SP-L (20–40 μL·L-1) and Cellubrixr L (15–25 μL· L-1). Results and discussion. The study of juice yield, cloud stability and the browning index showed that the coefficients of determination (R2 values) of these traits with the studied parameters were greater than 0.900. The optimized juice yield, cloud stability and browning index varied with specific values chosen for the five parameters mentioned above. Conclusions. Finally, the use of 30 μ L·L-1 Pectinexr Ultra SP-L and 22 μL·L-1 Cellubrix at 45 °C, for 43 min, at pH 5.5, was found to be the optimum set of conditions for processing cloudy mango juice. [ABSTRACT FROM PUBLISHER]

Semiconductor quantum dots (QDs) are promising fluorescence probes for immuofluorescence assay in the biological applications. However, water solubilization and non-specific binding are two critical issues to be addressed for the practical uses. Here, we reported a new type of QDs with combined silica and polymer coating. QDs with excellent colloidal properties were prepared via carboxylation of the amino groups on the surface of silica-coated QDs by reacting with multi-carboxyl poly (acrylic acid) (PAA). Hydrodynamic size of PAA-functionalized silica-coated QDs was around 40 nm. They were highly fluorescent (about 47.8% quantum yield). No precipitate of QDs was observed after 3 month storage at 4 °C. When cancer cells (HeLa) were used, the functionalized QDs exhibited little or no non-specific cellular binding. The results from in vitro experiments indicated that PAA-functionalized silica-coated QDs-antibody bioconjugates had excellent antigen-capture ability and exhibited little or no non-specific binding to polystyrene spheres which were used to immobilize the antigen for immuoflurescence assay. The PAA-functionalized silica-coated QDs with improved colloidal properties could serve as excellent alternative fluorescent probes for biodetection. [ABSTRACT FROM AUTHOR]

The effect of soy protein subunit composition on the acid-induced aggregation of soymilk was investigated by preparing soymilk from different soybean lines lacking specific glycinin and β-conglycinin subunits. Acid gelation was induced by glucono-δ-lactone (GDL) and analysis was done using diffusing wave spectroscopy and rheology. Aggregation occurred near pH 5.8 and the increase in radius corresponded to an increase in the elastic modulus measured by small deformation rheology. Diffusing wave spectroscopy was also employed to follow acid gelation, and data indicated that particle interactions start to occur at a higher pH than the pH of onset of gelation (corresponding to the start of the rapid increase in elastic modulus). The protein subunit composition significantly affected the development of structure during acidification. The onset of aggregation occurred at a higher pH for soymilk samples containing group IIb (the acidic subunit A) of glycinin, than for samples prepared from Harovinton (a commercial variety containing all subunits) or from genotypes null in glycinin. The gels made from lines containing group I (A, A) and group IIb (A) of glycinin resulted in stiffer acid gels compared to the lines containing only β-conglycinin. These results confirmed that the ratio of glycinin/β-conglycinin has a significant effect on gel structure, with an increase in glycinin causing an increase in gel stiffness. The type of glycinin subunits also affected the aggregation behavior of soymilk. [ABSTRACT FROM AUTHOR]

Abstract: The surface and interfacial properties of gallic acid, catechin and quercetin, and their effect on the dispersion degree and the oxidative stability of olive oil oil-in-water (O/W) emulsions prepared using β-lactoglobulin and Tween 20 were studied. Gallic acid showed no effect on the surface properties while catechin was proven to be able to accumulate at the air/water interface, decreasing the surface tension values with increasing its concentration. All the phenolic antioxidants caused a decrease in the interfacial tension at the oil/water interface, even though only catechin and quercetin showed a concentration dependent behaviour. In emulsions, gallic acid did not affect the droplet size of the systems, catechin caused the formation of oil droplets bigger than those of the control, whilst quercetin improved the dispersion state of the emulsions with the increasing of its concentration. Gallic acid, despite its partitioning in the water phase due to its polarity, delayed the formation of both the hydroperoxides and TBARs and limited their accumulation. Catechin did not affect the formation of oxidation products whilst quercetin, among the tested antioxidants, caused the lowest formation of both hydroperoxides and TBARs through 33 days of storage. [Copyright &y& Elsevier]