Glass Packing Research Articles

Physical, optical, thermal, structural and mechanical properties of alkaline earth borate glasses

Binary alkaline earth borate glasses were synthesized via the melt quenching technique. The density and molar volume of the resultant glasses were determined experimentally. The glass optical basicity has been found to increase with the glass polarizability. The optical properties of the glasses were comprehensively analyzed, revealing a shift in the cutoff wavelength towards longer wavelengths with increasing glass optical basicity. Additionally, the optical band gap (Eg) was estimated. Structural investigations unveiled an increase in the abundance of BO4 units as the glass optical basicity increased. Furthermore, the glass transition temperature was observed to decrease with decreasing cation field strength. Glass packing density and B2O3 packing factor were calculated to assess structural variations. The longitudinal and shear velocities were determined using the pulse echo technique, providing insights into the elastic moduli of the glasses. The Makishima and Mackenzie approach was employed to predict the elastic moduli, yielding results in good agreement with experimental data. This comprehensive analysis sheds light on the relationship between composition, structure, and mechanical properties of binary alkaline earth borate glasses, offering valuable insights for potential applications.

Extending the glass formation of alkali tellurites

The physical properties of low alkali content tellurite glasses of composition xM2O.(1−x)TeO2 (0≤x≤0·35) have been previously collected in this laboratory. The twin-roller rapid quenching technique (cooling rate>105°C/s), used within a nitrogen environment, successfully and significantly extended the glass-forming range in the lithium and sodium tellurite systems. The upper range for modification has been extended from x=0·35 to 0·80 and up to x=0·625 for the lithium and sodium systems, respectively. In the K, Rb and Cs tellurites, the glass forming ranges were not increased. Glass transition temperature (Tg), crystallisation temperature (Tx), density, molar volume, packing fraction, ionic conductivity and Raman spectra were obtained for these glasses. These results showed structural changes as a function of composition and carbonate retention in the glasses as the amount of alkali modifier increased above x=0·5.

An order of magnitude enhancement in ductility of a metallic glass of peak rejuvenation

Exceptional ductility has been a long-sought-after property of metallic glasses, and cryogenic thermal cycling rejuvenation has been actively explored to enhance the plasticity of metallic glasses. By tuning the holding time and number of cycles of cryogenic thermal cycling processing, we here report a (Zr0.8125Cu0.1875)79Ni10Al10Nb1 metallic glass of peak rejuvenation with the plasticity of an order of magnitude higher than that of the as-cast glass, without sacrificing its strength. Characterizations indicate that the loose atomic packing of the metallic glass of peak rejuvenation facilitates the generation and proliferation of shear bands in the early stage of plastic deformation, and the resultant dense shear bands tend to be deflected due to their interaction with each other and/or structural inhomogeneity in the matrix, hindering their rapid propagation and in turn increasing the plasticity. The combination of high relaxation enthalpy and high plasticity obtained here is outstanding from the previous rejuvenated metallic glasses which have either high relaxation enthalpy or high plasticity, while never both. This work identifies an alloy system with very high efficiency in plasticity improvement through cryogenic thermal cycling rejuvenation and represents a promising guide for improving the plasticity of metallic glasses.

Pilot study: External surface contamination of gemcitabine and 5-fluorouracil on drug packaging.

Antineoplastic drugs (ADs) are commonly used pharmaceuticals for anticancer treatments. It has previously been shown that the external surface of drug vials frequently is contaminated with ADs. More than a decade ago methods to prevent occupational exposure were introduced by using plastic coverage of the glass vials or packing vials in a secondary plastic container. The aim of the pilot study was to determine contamination levels of ADs on different parts of AD packaging of two different commercially available drug vials on the Swedish market and to investigate the occurrence of cross contamination of ADs. Packagings of gemcitabine (GEM) and 5-fluorouracil (5-FU) were tested by wipe sampling. Five ADs; GEM, 5-FU, cyclophosphamide (CP), ifosfamide and etoposide were quantified using liquid chromatography mass spectrometry. AD contaminations were detected in 69% and 60% of the GEM and 5-FU packaging samples. Highest levels, up to approximately 5 µg/sample, were observed on the glass vials. The protective shrink-wrap of 5-FU vials and the plastic container of GEM were contaminated with low levels of 5-FU and GEM, respectively, and furthermore the 5-FU vials with shrink-wrap were cross-contaminated with GEM. Cross-contamination of CP and GEM was detected on 5-FU vials with plastic shrink-wrap removed. External contamination of ADs are still present at primary drug packagings on the Swedish market. Protection of AD vials by plastic shrink-wrap or a secondary plastic container does not remove the external contamination levels completely. The presence of cross contamination of ADs on drug packagings was also observed.

Effects of size ratio on particle packing in binary glasses

Mixtures of binary spheres represent prototypes of amorphous solids and can model metallic, granular, and colloidal glasses. However, the effects of the size ratio λ on amorphous structures are not well understood. Here, we revisit the controversial noncubic scaling law and the local sphere packing by systematically changing λ. Our simulations clarify the existence and mechanism of the noncubic scaling law for mean atomic volume, va∝q1−d, where q1 is the position of the first diffraction peak and d is a constant less than the space dimension D. We find that the scaling law holds at each λ in binary hard-sphere glasses and metallic glasses, but the exponent satisfies a universal power law, d∼(λ−λc)−γ, instead of being a constant. The decreasing trend of d(λ), the abnormal d>D and the divergence of d when λ approaches 1 are theoretically explained. Moreover, d begins to fluctuate at λ<1.2, indicating less stable glasses. Large and small spheres are better dispersed with more disordered structures at λ>1.2. At λ=1.2, various structural parameters change, and the number of icosahedral packing reaches the maximum. The results cast light and pose new challenges on amorphous structures of binary glasses.

Non-thermal plasma assisted CO2 conversion to CO: Influence of non-catalytic glass packing materials

The current research is focused on the decomposition of carbon dioxide (CO2) into carbon monoxide (CO) and oxygen (O2) in a non-thermal plasma reactor using dielectric barrier discharge (DBD) at ambient conditions. Pure CO2 was injected into the DBD reactor at a flow rate of 30 mL min-1, and the voltage was varied between 16 kV to 22 kV. The filamentary micro discharges generated during plasma has a significant effect on CO2 conversion. The effect of packing materials on CO2 conversion was investigated by packing non-catalytic materials such as quartz wool, glass capillary, glass wool, and glass beads in the discharge zone of the DBD reactor. Among the studied packing materials, quartz wool exhibited a maximum CO2 conversion of 9.3 % at a discharge power of 2.0 W and specific energy input (SEI) of 4.0 J mL-1. However, glass capillary exhibited the highest energy efficiency of 1.2 mmol kJ-1 at an SEI of 3.5 J mL-1.

Identification of medium range order defects and their critical effect on spallation of Cu64Zr36 metallic glass

The absence of a well-defined structural defect is a longstanding problem, acting as the obstacle for understanding of mechanical behavior in metallic glasses. Here, through a compelling integration of experimental and computational technologies containing Synchrotron X-ray diffraction, extended X-ray absorption fine structure spectroscopy (EXAFS) as well as atomistic simulations, we present more direct evidences for the existence of medium range order (MRO) defects based on the discontinuity of stiff icosahedral network. As revealed by the numerical simulation of spallation process for two Cu64Zr36 metallic glasses with different cooling history, the MRO defects can be used as the efficient predictor of void nucleation, as evidenced by the strong correlation between high MRO defects location and subsequent void sites. This observation implies that the initial distribution as well as further generation of MRO defects play a critical role for the mechanical failure process of metallic glasses. It can be also extended to experimental conditions since the atomic packing of metallic glasses in molecular dynamic (MD) simulations is in great agreement with that obtained from reality as characterized by results of X-ray and EXAFS.

Vapor deposition rate modifies anisotropic glassy structure of an anthracene-based organic semiconductor.

We control the anisotropic molecular packing of vapor-deposited glasses of ABH113, a deuterated anthracene derivative with promise for future organic light emitting diode materials, by changing the deposition rate and substrate temperature at which they are prepared. We find that at substrate temperatures from 0.65Tg to 0.92Tg, the deposition rate significantly modifies the orientational order in the vapor-deposited glasses as characterized by x-ray scattering and birefringence. Both measures of anisotropic order can be described by a single deposition rate-substrate temperature superposition (RTS). This supports the applicability of the surface equilibration mechanism and generalizes the RTS principle from previous model systems with liquid crystalline order to non-mesogenic organic semiconductors. We find that vapor-deposited glasses of ABH113 have significantly enhanced density and thermal stability compared to their counterparts prepared by liquid-cooling. For organic semiconductors, the results of this study provide an efficient guide for using the deposition rate to prepare stable glasses with controlled molecular packing.

Substantially enhanced plasticity of bulk metallic glasses by densifying local atomic packing

Introducing regions of looser atomic packing in bulk metallic glasses (BMGs) was reported to facilitate plastic deformation, rendering BMGs more ductile at room temperature. Here, we present a different alloy design approach, namely, doping the nonmetallic elements to form densely packed motifs. The enhanced structural fluctuations in Ti-, Zr- and Cu-based BMG systems leads to improved strength and renders these solutes’ atomic neighborhoods more prone to plastic deformation at an increased critical stress. As a result, we simultaneously increased the compressive plasticity (from ∼8% to unfractured), strength (from ∼1725 to 1925 MPa) and toughness (from 87 ± 10 to 165 ± 15 MPa√m), as exemplarily demonstrated for the Zr20Cu20Hf20Ti20Ni20 BMG. Our study advances the understanding of the atomic-scale origin of structure-property relationships in amorphous solids and provides a new strategy for ductilizing BMG without sacrificing strength.

Recycling Crushed Waste Beer Bottle Glass in Fired Clay Bricks

Waste glass is a readily available domestic material. Each year, around 257,000 tonnes of glass waste are produced in Victoria, and the majority is glass packings. Typically, mixed waste glass cullet is deposited in landfills due to the limited recycling techniques. As a result, landfills are facing a growing issue. Therefore, this study investigates the addition of waste beer bottle glass (BG) in fired clay bricks and examines the effects of varying firing temperatures on the physical and mechanical properties of the manufactured samples. Clay bricks containing 10% BG at a firing temperature of 950 °C depicted similar compressive strength results (41 MPa) to the control samples (42 MPa). The results of all tested bricks were found to be below the water absorption limit of 17%. The thermal conductivity of the bricks incorporating BG was investigated, and it was found that the thermal performance improved with the decreasing firing temperature. Moreover, an initial rate of absorption (IRA), XRD, and XRF analysis was conducted. The experimental results have been discussed and compared with the recommended acceptable properties for standard bricks.

Sustainable functionalized metal-organic framework NH2-MIL-101(Al) for CO2 separation under cryogenic conditions.

In this study, a sustainable NH2-MIL-101(Al) is synthesized and subjected to characterization for cryogenic CO2 adsorption, isotherms, and thermodynamic study. The morphology revealed a highly porous surface. The XRD showed that NH2-MIL-101(Al) was crystalline. The NH2-MIL-101(Al) decomposes at a temperature (>500°C) indicating excellent thermal stability. The BET investigation revealed the specific surface area of 2530m2/g and the pore volume of 1.32cm3/g. The CO2 adsorption capacity was found to be 9.55wt% to 2.31wt% within the investigated temperature range. The isotherms revealed the availability of adsorption sites with favorable adsorption at lower temperatures indicating the thermodynamically controlled process. The thermodynamics showed that the process is non-spontaneous, endothermic, with fewer disorders, chemisorption. Finally, the breakthrough time of NH2-MIL-101(Al) is 31.25% more than spherical glass beads. The CO2 captured by the particles was 2.29kgm-3. The CO2 capture using glass packing was 121% less than NH2-MIL-101(Al) under similar conditions of temperature and pressure.

Over What Length Scale Does an Inorganic Substrate Perturb the Structure of a Glassy Organic Semiconductor?

While the bulk structure of vapor-deposited glasses has been extensively studied, structure at buried interfaces has received little attention, despite being important for organic electronic applications. To learn about glass structure at buried interfaces, we study the structure of vapor-deposited glasses of the organic semiconductor DSA-Ph (1,4-di-[4-(N,N-diphenyl)amino]styrylbenzene) as a function of film thickness; the structure is probed with grazing incidence X-ray scattering. We deposit on silicon and gold substrates and span a film thickness range of 10-600 nm. Our experiments demonstrate that interfacial molecular packing in vapor-deposited glasses of DSA-Ph is more disordered compared to the bulk. At a deposition temperature near room temperature, we estimate ∼8 nm near the substrate can have modified molecular packing. Molecular dynamics simulations of a coarse-grained representation of DSA-Ph reveal a similar length scale. In both the simulations and the experiments, deposition temperature controls glass structure beyond this interfacial layer of a few nanometers.

Nonmonotonic behavior in dense assemblies of active colloids.

We study experimentally a sediment of self-propelled Brownian particles with densities ranging from dilute to ergodic supercooled to nonergodic glass to nonergodic polycrystal. In a companion paper, we observe a nonmonotonic response to activity of relaxation of the nonergodic glass state: a dramatic slowdown when particles become weakly self-propelled, followed by a speedup at higher activities. Here we map ergodic supercooled states to standard passive glassy physics, provided a monotonic shift of the glass packing fraction and the replacement of the ambient temperature by the effective temperature. However, we show that this mapping fails beyond glass transition. This failure is responsible for the nonmonotonic response. Furthermore, we generalize our finding by examining the dynamical response of another class of nonergodic systems: polycrystals. We observe the same nonmonotonic response to activity. To explain this phenomenon, we measure the size of domains where particles move in the same direction. This size also shows a nonmonotonic response, with small lengths corresponding to slow relaxation. This suggests that the failure of the mapping of nonergodic active states to a passive situation is general and is linked to anisotropic relaxation mechanisms specific to active matter.

Dense Glass Packing Can Slow Reactions with an Atmospheric Gas.

Previous work utilizing crystal polymorphs has established the importance of the molecular packing environment for modulating solid-gas reactivity. Here, we show, for the first time, that the chemical stability of an amorphous material in contact with a reactive gas can be significantly improved by controlling glass packing. We utilize the reaction of indomethacin with ammonia as this system has been well-characterized for crystalline polymorphs. For these experiments, physical vapor deposition (PVD) is used to prepare glasses of indomethacin with a range of densities and thermal stabilities. The indomethacin-ammonia reactivity is assessed through the increase in mass of glassy thin films exposed to ammonia gas, as characterized by a quartz crystal microbalance. Indomethacin glasses vapor-deposited at substrate temperatures below the glass transition temperature (Tg) show unprecedented decrease in reaction rates relative to the liquid-cooled glass, by as much as 1 order of magnitude, with the densest glasses having the slowest reactions. The diminished solubility of ammonia in dense PVD glasses is found to be a major factor in their remarkable chemical stability. As chemically stable amorphous solids are in demand for applications including pharmaceuticals and organic electronics, this work provides a strategy to improve performance of these materials.

Power–Law Feature of Structure in Metallic Glasses

The atomic packing in metallic glasses (MGs) is a long-standing issue. We investigate the atomic packing on different length scales for various MGs by X-ray diffraction and small-angle X-ray scatte...

Institutional aspects of solid waste treatment in Russia

Institutional aspects of solid waste treatment in Russia

Buckwheat seed quality during the five-year storage in various packing materials

Buckwheat (Fagopyrum esculentum Moench.) seed, produced in three locations, was used in the present study. Seed was stored in paper, glass, wood and PVC packing materials under room temperature conditions (18°C) for five years. The following parameters of seed quality were observed: viability, germination, dormancy and a 1000-seed weight. Standard laboratory methods were applied in the studies. The lowest viability after harvest was recorded in seeds stored in glass or pvc packing materials. All factors pointed to a great significance in the expression of viability, germination and seed weight maintenance. The highest value of germination (99%) was recorded in seeds produced in the location Karbulovo after two-year storage in the paper packing material. In the second year of storage, seed dormancy in paper packing material amounted to 0–0.1%. The seed weight changed during the storage period from 33.9 g to 24.4 g. The weight loss was the lowest in seeds stored in the paper packing material. The germination decline was slower in large than in small seeds. Obtained results indicate the importance of packing material for maintenance of seed qualitative traits. According to the gained results, seeds packed in paper packing material mostly retained their physiological and morphological traits.

Efficient CO2 capture using NH2–MIL–101/CA composite cryogenic packed bed column

CO2 capture using cryogenic packed bed with spherical glass packing material has great potential for applications in the natural gas industry. However, the influence of packing material on their performance has been rarely studied. In the present work, some novel packing materials, including Cellulose Acetate and CA/NH2–MIL–101(Al) were used to enhance the performance of the cryogenic packed bed. Pressure drop was determined as a function of specific surface area and module filling fraction experimentally. The CO2 capture efficiency of the system, axial temperature profile study during cooling and CO2 recovery steps for the spherical glass beads, CA hollow fibres and composite CA/NH2–MIL–101(Al) hollow fibres were also investigated. It was found that the hollow fibres reduce the pressure drop by a factor of 61% and 33% compared with the pressure drop caused by the spherical glass beads and monofilament fibres, respectively. The specific surface area provided by the hollow fibres was 230% and 122% more than that offered by the glass beads and monofilament fibres respectively. It was also observed that the CO2 capture efficiency of composite hollow fibres was 141.9% more than spherical glass beads and 9.5% greater than the pure CA hollow fibres. The temperature profile study reveals that pure CA and the composite CA/NH2–MIL–101(Al) hollow fibres require less energy for cooling than glass beads and provides higher bed saturation time. It was concluded that the NH2–MIL–101(Al) hollow fibre reduces the pressure drop and capital cost along with increasing the CO2 capture efficiency.

Anisotropic Vapor-Deposited Glasses: Hybrid Organic Solids

The term "organic solids" encompasses both crystals and glasses. Organic crystals are commonly grown for purification and structure determination and are being extensively explored for applications in organic electronics including field effect transistors. The ability to control the packing of one molecule relative to its neighbors is of critical importance for most uses of organic crystals. Often, anisotropic packing is also highly desirable as it enhances charge transport and optimizes light absorption/emission. When compared to crystals, the local packing in organic glasses is highly disordered and often isotropic. Glasses, however, offer two key advantages with respect to crystals. First, glasses typically lack grain boundaries and thus exhibit better macroscopic homogeneity. Second, glass composition can often be varied over a wide range while maintaining homogeneity. Besides electronic materials, many modern plastics used in a wide range of technologies are organic glasses, and the glassy state is being increasingly utilized to deliver pharmaceuticals because of higher bioavailability. In this article, we introduce vapor-deposited organic glasses as hybrid materials that combine some of the useful features of crystals and traditional liquid-cooled glasses. Physical vapor deposition produces glasses by directly condensing molecules from the gas phase onto a temperature-controlled substrate and allows film thickness to be controlled with nanometer precision. Just as liquid-cooled glasses, vapor-deposited glasses have smooth surfaces and lack grain boundaries. These attributes are critical for applications such as organic light emitting diodes (OLEDs), in which vapor-deposited glasses of organic semiconductors form the active layers. In common with crystals, vapor-deposited glasses can exhibit anisotropic packing, and the extent of anisotropy can be comparable to that of the typical organic crystal. For vapor-deposited glasses, in contrast to crystals, anisotropic packing can generally be controlled as a continuous variable. Deposition conditions can be chosen to produce glasses with significant molecular orientation (molecules "standing up" or "lying down" relative to the substrate), and π-stacking can be directed along different directions relative to the substrate. Over the last five years, we have gained a fundamental understanding of the mechanism that controls the anisotropy of vapor-deposited glasses and learned how to control many aspects of anisotropic packing. Two key elements that enable such control are the high mobility present at the surface of an organic glass and the tendency of the surface to promote anisotropic packing of molecules. In contrast to traditional epitaxial growth, for vapor-deposited glasses, the free surface (not the substrate) acts as a template that controls the structure of a growing film. The structure of any given layer is decoupled from those beneath it, thereby providing considerable freedom in producing layered glassy structures.

Determination of phthalates in juice product by high-performance liquid chromatography/mass spectrometry

The paper presents the research results obtained after determination of the persistent organic pollutants of the environment - phthalates in domestic juice products with the use of high-performance liquid chromatography/ mass spectrometry (HPLC/MS/MS) with application of solid-phase extraction as a method of sample preparation. Selective determination of phthalates in fruit and vegetable juices by HPLC/MS/MS method has been provided through parent and child ions' monitoring that are formed during ionization of the molecules of the studied compounds in the electrostatic spray of isomers on a reversed-phase column. The analysis of the samples of juice product revealed the presence of 11 phthalates out of 13 studied in concentration range from 0.4 up to 59.26 mg/dm3. The maximum amount of phthalates was found in juices with pulp 31.9-59.26 mg/dm3 (tetrahedral package), the minimum content of phthalates 0.4 mg/dm3 was detected in flavoured beverages (polyethylene terephthalate packing) and 1 mg/dm3 in the fruit-and-vegetable nectar (glass packing). The most samples contained from 3 to 8 phthalates with total content of 0.4-5.82 mg/dm3. The most prevailing pollutants of the analyzed samples were di-n-octyl phthalate found in 100% of samples, dinonyl phthalate and di (2-ethylhexyl) phthalate, presented in 70-80% of samples. The maximum pollution density of the juice samples was noted for di-n-octyl phthalate, di (2-ethylhexyl) phthalate, diisononyl phthalate and diisobutyl phthalate.