Attractive Glass Research Articles

Development Strategy of Klanceng Honey Livestock (Trigona Sp) in Lubuk Raja, Ogan Komering Ulu District

Honey bee cultivation is one of the livestock businesses that can play a role in meeting the economic needs of the community. This research was conducted in order to find out what strategies are appropriate in developing the Klanceng (Trigona sp) honey livestock business so that the marketing and development of the Klanceng (Trigona sp) honey livestock business can develop and be able to add economic value to the people of Lubuk Raja District, Ogan Komering Ulu Regency. The results of this research are internal factors include strengths and weaknesses, namely that employees have undergone training, the availability of nectar production facilities is quite extensive, cultivation management has been implemented and they already have market share. The weaknesses of the Klanceng Honey Farming Business (Trigona SP) in Lubuk Raja District, Ogan Komering Ulu Regency are seasonal factors, funds, not being able to harvest every day, simple product packaging and lack of knowledge of marketing media. External factors include opportunities and threats. The strategiesis using the S-O strategy or power of opportunity strategy, namely utilizing government support in expanding the marketing area for honey products, utilizing nearby shops and honey collecting agents to market the harvest of Klanceng honey bee products (Trigona sp), then utilizing social media as a promotional tool honey products, as well as changing old packaging in the form of marjan bottles into more attractive glass bottles, developing technology for cultivating livestock Klanceng honey bees (Trigona sp) and finally renting land in an area that is in season.

Theoretical study of kinetic arrest, shear elastic modulus, and yielding in simple biphasic colloidal mixtures.

Based on integrating microscopic statistical mechanical theories for structure and ideal kinetic arrest at the naive mode coupling level, we study dynamic localization, the linear elastic shear modulus, applied stress induced modulus softening, and the absolute yielding of simple biphasic binary mixtures composed of equal diameter hard and attractive spheres. The kinetic arrest map is a rich function of total packing fraction, strength of attraction, and mixture composition. The gel to attractive ideal glass transition, the degree of glass melting re-entrancy, and the crossover boundary separating repulsive glasses from attractive glasses vary with the mixture composition. Exponential and/or apparent (high) power law dependences of the elastic shear modulus on the total packing fraction are predicted with effective exponents or exponential prefactors that are sensitive to mixture composition and location in the kinetic arrest map. An analysis of the effective mean square force on a tagged particle that induces dynamic localization reveals a compensation effect between structural correlations and degree of particle localization, resulting in the emergence of a weaker dependence of the shear modulus on mixture composition at very high attraction strengths. Based on a microrheologically inspired formulation of how external stress weakens particle localization and the shear modulus, we analyze mechanical-induced modulus softening and absolute yielding, defined as a discontinuous solid-to-fluid stress-induced transition that can occur in either one or two steps. Estimates of the corresponding yield strains predict that the binary mixture becomes more brittle with increasing sticky particle composition and/or attraction strength.

Interparticle interaction-dependent jamming in colloids: insights into glass transition and morphology modulation during rapid evaporation-induced assembly.

Understanding the role of interparticle interactions in jamming phenomena is essential for gaining insights into the intriguing glass transition behavior observed in atomic and molecular systems. In this study, we investigate the jamming behavior of colloids with tunable interparticle interactions during evaporation-induced assembly (EIA). By manipulating the interaction among charged colloids using cationic polyethyleneimine (PEI) through electro-sorption and subsequent free polymer induced repulsion, we observe distinct jamming behavior in silica colloids during EIA, depending on the interparticle interactions. Silica colloids with strong repulsive interactions exhibit a repulsive colloidal glass state with a volume fraction of silica colloids in supraparticle ϕ ∼ 0.70. On the other hand, PEI-mediated attractive interactions among silica colloids lead to an attractive colloidal glass phase with a significantly lower ϕ ∼ 0.43. Free polymer induced repulsion of colloids at higher PEI concentration once again results in a repulsive glassy state with ϕ ∼ 0.61. Furthermore, we revealed that interparticle interactions not only influence the jamming behavior but also play a significant role in shaping the morphology of self-assembled structures during EIA, and the assembled structure undergoes a morphological reentrant transition from a doughnut-like shape to a spherical form and again back to a doughnut-like configuration. Jamming-dependent evolution of micropores and dynamics of the confined PEI have been probed using positron annihilation lifetime spectroscopy (PALS) and broadband dielectric spectroscopy (BDS). PALS reveals distinct variations in the micropores of the supraparticles with different PEI loadings, confirming the impact of jamming on the evolution of the micropores within the supraparticles. BDS measurements uncover non-monotonic dynamics of PEI molecules confined in the evolved pore network. It is revealed that the reentrant jamming behavior of colloids, modulated by PEI, holds profound significance for the long-term stability of supraparticles.

Aesthetic Clinic and Beauty Myths in Indonesia: Discourse Analysis of Beauty Representation in Instagram Accounts

The purpose of this study is to uncover the beauty myths displayed in the Instagram accounts of aesthetic clinics in Indonesia. This study uses a qualitative research method with a critical discourse analysis approach by Sara Mills. Results indicates that; First, the existence of women is shown as an object, where women are victims of symbols and beauty standards that arereconstructed and reproduced by the subject (the storyteller), namely the Instagram accounts of beauty clinics @dermaster_id, @ertosbeautyclinic, and @natashaskincare. Women as objects shown cannot be separated from the beauty myth. Second, there are two categories of beauty representations formed in the Instagram accounts of beauty clinics @dermaster_id, @ertosbeautyclinic, and @natashaskincare, namely men beauty representations, which consist of smooth faces, young looks, and firm jaws, and women beauty representations consist of; (1) thin cheeks, firm jaw, and firm skin, (2) smooth, acne-free, and attractive skin, (3) glass skin and slim, and (4) halal beauty. The implications of this research are this study is expected to contribute information and enrich the repertoire of social science especially sociology, also for the development of research on sociology of body, feminism study, and sociology of gender and media.

Arrested spinodal decomposition of the screened symmetric restricted primitive model.

Amorphous solids, such as glasses and gels, arise as the asymptotic limit of non-equilibrium and irreversible relaxation aging processes. These amorphous solids form when the system is suddenly and deeply quenched in the dynamic arrest region. We use the non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory to investigate the formation of such structures via arrested spinodal decomposition in the screened symmetric restricted primitive model. We propose a direct correlation function that allows us to derive an expression for the functional derivative of the chemical potential, which serves as the necessary input in the NE-SCGLE theory. By analyzing the asymptotic localization length and the asymptotic characteristic length, we identify different classes of dynamic arrest states as a function of the density and the final quench temperature. The system features simultaneously attractive and repulsive interactions, resulting in different arrested regions in the non-equilibrium phase diagram for a given screened parameter: (i) ionic glasses, (ii) electrostatic gels, and (iii) attractive glasses. Finally, by collapsing the asymptotic effective structure factors at a typical fractal dimension of df = 3, we confirm the formation of gels slightly above the glass-gel transition in the arrested phase diagram.

Broadband tunable infrared emission of Ni2+-doped ZnGa/AlO4 integrated transparent glass ceramics

ZnGa/AlO4 provides an octahedral coordination field in which Ni2+ serves as the luminescent center and combines with highly attractive transparent glass ceramics, playing a crucial role in achieving broadband near-infrared (NIR) emission. Transparent glass-ceramics embedded with ZnGa/AlO4:Ni2+ mixed crystals prepared by secondary high-temperature melting methods retain the structural characteristics of the dual-phase crystal, which was confirmed by a series of structural and morphological characterization. Through fine tailoring, the surrounding Ni2+ ligand field environment was transformed, realizing special composite NIR emission characteristics with a half-maximum width (FWHM) exceeding 280 nm, which achieved the best results for now in kinds of similar materials. The results show that the NIR emission of ZnGa/AlO4:Ni2+-doped transparent glass-ceramics is significantly broadened while maintaining a high level and a long lifetime, which makes it an excellent candidate material for IR light sources and broadband fiber amplifiers.

Complex optical transport, dynamics, and rheology of intermediately attractive emulsions

Introducing short-range attractions in Brownian systems of monodisperse colloidal spheres can substantially impact their structures and consequently their optical transport and rheological properties. Here, for size-fractionated colloidal emulsions, we show that imposing an intermediate strength of attraction, well above but not much larger than thermal energy (approx 5.6k_{textrm{B}}T), through micellar depletion leads to a striking notch in the measured inverse mean free path of optical transport, 1/ell ^*, as a function of droplet volume fraction, phi. This notch, which appears between the hard-sphere glass transition, phi _{textrm{g}}, and maximal random jamming, phi _{textrm{MRJ}}, implies the existence of a greater population of compact dense clusters of droplets, as compared to tenuous networks of droplets in strongly attractive emulsion gels. We extend a prior decorated core-shell network model for strongly attractive colloidal systems to include dense non-percolating clusters that do not contribute to shear rigidity. By constraining this extended model using the measured 1/ell ^*(phi ), we improve and expand the microrheological interpretation of diffusing wave spectroscopy (DWS) experiments made on attractive colloidal systems. Our measurements and modeling demonstrate richness and complexity in optical transport and shear rheological properties of dense, disordered colloidal systems having short-range intermediate attractions between moderately attractive glasses and strongly attractive gels.

Rheological study of nanoemulsions with repulsive and attractive interdroplet interactions.

Nanoemulsions have adjustable transparency, tunable rheology, high stability, and low sensitivity to changes in pH and temperature, which make them interesting for applications such as low-fat and low-calorie foods. In this research, we study model concentrated nanoemulsions which are stabilized by sodium dodecyl sulfate (SDS). To prepare samples in different structural states, semi-dilute nanoemulsions are prepared at 25% droplet volume fraction (φ), after which evaporating the continuous phase at room temperature leads to concentrated nanoemulsions up to 60% volume fraction. Surfactant concentration is also tuned to induce different interdroplet interactions so that concentrated nanoemulsions in repulsive glass, attractive glass, and gel states are achieved. Rheological properties of nanoemulsions with different structural states are comprehensively studied over a volume fraction range. Utilizing the existing predictive models for (nano)emulsion rheology reveals a more satisfactory prediction for repulsive systems than systems with attractive interactions. In addition, a master curve is constructed for storage and loss moduli of nanoemulsions with different interdroplet interactions. The present work offers control over physicochemical properties of nanoemulsions for design of new food products with enhanced quality and functionality.

Nanoemulsion polymerization and templating: Potentials and perspectives

The current study aims to provide an outlook on the nanoemulsions templating method by discussing their potentials to produce different polymers and evaluating challenges that might be posed during emulsification and polymerization. Tunable properties such as controllable droplet size, volume fraction, composition, and interdroplet interactions provide tools for controlling the structure of nanoemulsions and nanoemulsion-templated polymers. Therefore, these properties along with a phase diagram including the liquid, gel, attractive glass, and repulsive glass states of nanoemulsions are discussed in this Perspective. Although the synthesis of nanoparticles is the main application of nanoemulsion templating in the literature, polymerization of monomers in the continuous phase of nanoemulsions has potential to expand their applications and produce complex structured porous polymers. Nanoemulsion characteristics can also be tuned to produce porous polymers with desirable properties. This Perspective also looks at multiple nanoemulsions with multi-phase droplets, which recently have become of great interest for producing nanoparticles with complex morphologies. Multiple nanoemulsions and their templating provide new avenues for certain applications particularly in pharmaceutical and nanotechnology industries.

Clusters in colloidal dispersions with a short-range depletion attraction: Thermodynamic identification and morphology

HypothesisParticle aggregation is ubiquitous for many colloidal systems, and drives the phase separation or the formation of materials with a highly heterogeneous large-scale structure, such as gels, porous media and attractive glasses. While the macroscopic properties of such materials strongly depend on the shape and size of these particle aggregates, the morphology and underlining aggregation physical mechanisms are far from being fully understood. Recently, it has been proposed that for reversible colloidal aggregation, the cluster morphology in the case of colloids interacting with short-range attractive forces is determined by a single variable, namely, the reduced second virial coefficient, B2∗. ExperimentsWe examined this proposal by performing confocal microscopy experiments and computer simulations on a large collection of short-ranged attractive colloidal systems with different values of the attraction strength and range. FindingsWe show that in all cases a connection between the colloidal cluster morphology and B2∗ can be established both in experiments and simulations. This physical scenario holds at all investigated thermodynamic conditions, namely, in the fluid state, in the metastable region and in non-equilibrium conditions. Our findings support the connection between reversible colloidal aggregation and the so-called extended law of corresponding states.

Photosensitivity of barium germano-gallate glasses under femtosecond laser direct writing for Mid-IR applications

Barium germano-gallate glasses are attractive glass hosts for photonic applications in the mid-infrared region up to 6 μm. In this work, we investigate the photosensitivity of such glasses under femtosecond laser, with an emphasize on the formation of refractive index changes. Six glasses with varying compositions (including addition of K, Na, Y, and La) were studied. We observed several transformation regimes in the pulse energy – repetition rate landscape: Type I (isotropic refractive index change) and a spatial broadening regime with a phase shift Δϕ > 2π rad at 550 nm. This translates into refractive index changes Δn > 10 −2 and is comparable to values obtained in most chalcogenide glasses. The effect of glass composition on Δϕ appears correlated to the number of non-bridging oxygen presented in the glass and is brought to evidence by monitoring the Cations/GaO 3/2 ratio. This provides a way to design a range of germano-gallate glasses suitable to imprinting high refractive index contrast.

Structural and short-time vibrational properties of colloidal glasses and supercooled liquids in the vicinity of the re-entrant glass transition.

We investigate the short-time vibrational properties and structure of two-dimensional, bidisperse, colloidal glasses and supercooled liquids in the vicinity of the re-entrant glass transition, as a function of interparticle depletion attraction strength. The long-time spatiotemporal dynamics of the samples are measured to be non-monotonic, confirming that the suspensions evolve from repulsive glass to supercooled liquid to attractive glass with increasing depletion attraction. Here, we search for vibrational signatures of the re-entrant behavior in the short-time spatiotemporal dynamics, i.e., dynamics associated with particle motion inside its nearest-neighbor cage. Interestingly, we observe that the anharmonicity of these in-cage vibrations varies non-monotonically with increasing attraction strength, consistent with the non-monotonic long-time structural relaxation dynamics of the re-entrant glass. We also extract effective spring constants between neighboring particles; we find that spring stiffness involving small particles also varies non-monotonically with increasing attraction strength, while stiffness between large particles increases monotonically. Last, from study of depletion-dependent local structure and vibration participation fractions, we gain microscopic insight into the particle-size-dependent contributions to short-time vibrational modes in the glass and supercooled liquid states.

Glass and Jamming Rheology in Soft Particles Made of PNIPAM and Polyacrylic Acid.

The phase behaviour of soft colloids has attracted great attention due to the large variety of new phenomenologies emerging from their ability to pack at very high volume fractions. Here we report rheological measurements on interpenetrated polymer network microgels composed of poly(N-isopropylacrylamide) (PNIPAM) and polyacrylic acid (PAAc) at fixed PAAc content as a function of weight concentration. We found three different rheological regimes characteristic of three different states: a Newtonian shear-thinning fluid, an attractive glass characterized by a yield stress, and a jamming state. We discuss the possible molecular mechanisms driving the formation of these states.

Optimization and semi‐automatic evaluation of a frosting process for a soda lime silicate glass based on phosphoric acid

AbstractChemical glass frosting processes are widely used to create visual attractive glass surfaces. A commonly used frosting bath mainly contains ammonium bifluoride (NH4HF2) mixed with hydrochloric acid (HCl). The frosting process consists of several baths. Firstly, the preliminary bath to clean the object. Secondly, the frosting bath which etches the rough light scattering structure into the glass surface. Finally, the washing baths to clean the frosted object. This is where the constituents of the preceding steps accumulate and have to be filtered from the sewage. In the present contribution, phosphoric acid (H3PO4) was used as a substitute for HCl to reduce the amount of ammonium (NH4+) and chloride (Cl−) dissolved in the waste water. In combination with magnesium carbonate (MgCO3), it allows the precipitation of ammonium within the sewage as ammonium magnesium phosphate (MgNH4PO4). However, a trivial replacement of HCl by H3PO4within the frosting process causes extensive frosting errors, such as inhomogeneous size distributions of the structures or domains that are not fully covered by these structures. By modifying the preliminary bath composition, it was possible to improve the frosting result considerably. To determine the optimal composition of the preliminary bath, a semi‐automatic evaluation method has been developed. This method renders the objective comparison of the resulting surface quality possible.

Mechanisms of two-step yielding in attractive colloidal glasses

A combination of experiments and Brownian Dynamics simulations is utilized to examine the mechanisms of yielding and flow in attractive colloidal glasses during start-up shear flow. In both experiments and simulations, the transient stress exhibits two stress peaks indicative of two-step yielding processes. The first yield depends largely on details of interparticle potential whereas the second yield is independent of the potential and takes place at strain (≃20%), at which a purely repulsive glass yields. The stress decomposition into repulsive (hard sphere, HS) and attractive contributions reveals that there are strong contributions of both types of stresses into the first stress peak whereas the second stress peak is mainly linked with HS stresses. The transient stress during start-up shear originates from the change in the averaged pair orientation. At the first stress peak, bonded particles (causing attractive stresses) show the maximum orientation along the extension axis with colliding particles (causing HS stresses) being locally oriented along the compression axis. However, at the second stress peak, collided particles show the maximum orientation along the compression axis with particles escaping their cages along the extension axis similar to a HS glass. Analysis of particle dynamics shows that yielding takes place through a two-step shear-activated hopping process in which first shear flow takes particles out of their attractive constraints. The length scale associated to this process is at the order of attraction range (bond length). Subsequently, cage escape of particles sets the second process which leads to a complete yielding and flow.

Microscopic theory of onset of decaging and bond-breaking activated dynamics in ultradense fluids with strong short-range attractions.

We theoretically study thermally activated "in cage" elementary dynamical processes that precede full structural relaxation in ultradense particle liquids interacting via strong short-range attractive forces. The analysis is based on a microscopic theory formulated at the particle trajectory level built on the dynamic free energy concept and an explicit treatment of how attractive forces control the formation and lifetime of physical bonds. Mean time scales for bond breaking, the early stage of cage escape, and non-Fickian displacement by a fixed amount are analyzed in the repulsive glass, bonded repulsive (attractive) glass, fluid, and dense gel regimes. The theory predicts a strong length-scale-dependent growth of these time scales with attractive force strength at fixed packing fraction, a much weaker slowing down with density at fixed attraction strength, and a strong decoupling of the shorter bond-breaking time with the other two time scales that are controlled mainly by perturbed steric caging. All results are in good accord with simulations, and additional testable predictions are made. The classic statistical mechanical projection approximation of replacing all bare attractive and repulsive forces with a single effective force determined by pair structure incurs major errors for describing processes associated with thermally activated escape from transiently localized states.

Microscopic theory of the influence of strong attractive forces on the activated dynamics of dense glass and gel forming fluids.

We theoretically study the nonmonotonic (re-entrant) activated dynamics associated with a finite time scale kinetically defined repulsive glass to fluid to attractive glass transition in high volume fraction particle suspensions interacting via strong short range attractive forces. The classic theoretical "projection" approximation that replaces all microscopic forces by a single effective force determined solely by equilibrium pair correlations is revisited based on the "projectionless dynamic theory" (PDT). A hybrid-PDT approximation is formulated that explicitly quantifies how attractive forces induce dynamical constraints, while singular hard core interactions are treated based on the projection approach. Both the effects of interference between repulsive and attractive forces, and structural changes due to attraction-induced bond formation that competes with caging, are included. Combined with the microscopic Elastically Collective Nonlinear Langevin Equation (ECNLE) theory of activated relaxation, the resultant approach appears to properly capture both the re-entrant dynamic crossover behavior and the strong nonmonotonic variation of the activated structural relaxation time with attraction strength and range at very high volume fractions as observed experimentally and in simulations. Testable predictions are made. Major differences compared to both ideal mode coupling theory and ECNLE theory based on the full force projection approximation are identified. Calculations are also performed for smaller time and length scale intracage dynamics relevant to the non-Gaussian parameter based on analyzing the dynamic free energy that controls particle trajectories. Implications of the new theory for thermal glass forming liquids with relatively long range attractive forces are briefly analyzed.

Tracer transport in attractive and repulsive supercooled liquids and glasses.

The transport of small penetrants through disordered materials with glassy dynamics is encountered in applications ranging from drug delivery to chemical separations. Nonetheless, understanding the influence of the matrix structure and fluctuations on penetrant motions remains a persistent challenge. Here, we use event-driven molecular dynamics to investigate the transport of small, hard-sphere tracers embedded in matrices of square-well particles. Short-range attractions between matrix particles give rise to reentrant dynamics in the supercooled regime, in which the liquid's relaxation time increases dramatically upon heating or cooling. Heating results in a "repulsive" supercooled liquid where relaxations are frustrated by steric interactions between particles, whereas cooling produces an "attractive" liquid in which relaxations are hindered by long-lived interparticle bonds. Further cooling or heating, or compression, of the supercooled liquids results in the formation of distinct glasses. Our study reveals that tracer transport in these supercooled liquids and glasses is influenced by the matrix structure and dynamics. The relative importance of each factor varies between matrices and is examined in detail by analyzing particle mean-square displacements, caging behavior, and trajectories sampled from the isoconfigurational ensemble. We identify features of tracer dynamics that reveal the spatial and temporal heterogeneity of the matrices and show that matrix arrest is insufficient to localize tracers.

Role of particle morphology in the yielding behavior of dense thermosensitive microgel suspensions

ABSTRACTThe yielding behavior of dense thermosensitive microgel suspensions of poly(N‐isopropylacrylamide) with two different particle morphologies viz core–shell (CS) morphology and particles with uniform crosslink density were studied. Structural properties were examined using dynamic light scattering and yielding behavior was investigated by nonlinear oscillatory rheology. Suspensions of particles with uniform crosslinking density showed a typical hard sphere like behavior with the loss modulus (G″) exhibiting a single peak due to cage breaking while CS type particles shows a double yielding at different ranges of strain similar to that seen in attractive colloidal glasses. The first yielding process in CS microgels is interpreted as due to the disentanglement of the overlapped polymer chains from the shells of the neighboring microgels and the second yielding process due to the breakage of cages formed by neighboring microgel particles. Current study suggests that the interpenetration of polymer chains at high concentrations sets in an attractive like potential leading to double yielding phenomena in an otherwise purely repulsive system. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48625.

Colloidal gel elasticity arises from the packing of locally glassy clusters

Colloidal gels formed by arrested phase separation are found widely in agriculture, biotechnology, and advanced manufacturing; yet, the emergence of elasticity and the nature of the arrested state in these abundant materials remains unresolved. Here, the quantitative agreement between integrated experimental, computational, and graph theoretic approaches are used to understand the arrested state and the origins of the gel elastic response. The micro-structural source of elasticity is identified by the l-balanced graph partition of the gels into minimally interconnected clusters that act as rigid, load bearing units. The number density of cluster-cluster connections grows with increasing attraction, and explains the emergence of elasticity in the network through the classic Cauchy-Born theory. Clusters are amorphous and iso-static. The internal cluster concentration maps onto the known attractive glass line of sticky colloids at low attraction strengths and extends it to higher strengths and lower particle volume fractions.