Foaming

Effects of an ionic liquid, 1-n-tetradecyl-3-methylimidazolium bromide ([C14MIM] Br), as a foaming additive on the foaming behavior of polypropylene(PP) by supercritical CO2 technique was reported. Mass ratio of PP/[C14MIM] Br up to 100: 10 was incorporated via melt blending. The melting behavior and fractured morphology of PP/[C14MIM] Br samples were investigated by differential scanning calorimetry(DSC) and scanning electron microscopy(SEM), respectively. The CO2 sorption was measured by commonly accepted gravimetric method. The results of DSC and CO2 sorption experiments show that [C14MIM] Br has little effect on the crystallinity, melting point and the mass uptake of CO2 of PP. SEM images reveal that [C14MIM] Br forms a well-dispersed phase, whose size increases with [C14MIM] Br content, in the PP matrix. The foamed PP/[C14MIM] Br samples exhibit close cell structure, increased cell size and decreased unfoamed region and bulk density, compared with pure PP foamed under the same saturation conditions of 155 degrees C/10 MPa, indicating ionic liquid [C14MIM] Br has significant effect on the foaming behavior of PP.
Chemical Journal of Chinese Universities -Chinese Edition- 05/2010; 31(5):861-863.

The effects of different ultrasound powers (150 W and 375 W) and exposure times (3 min and 6 min) on physico-functional properties of liquid whole eggs were investigated. Whipping capacity, foaming stability, pH, L*, a*, b* color, package headspace O2 and CO2 gas concentration were analyzed at weekly intervals during storage (5-6 weeks at 4°C). Ultrasound has improved the whipping capacity and maintained quality criteria’s in increasing shelf life during storage, stabilizing pH and limiting CO2 especially in 375W-6 min. Ultrasound has provided a significant increase on whipping capacity values from 410±14.14 (control/untreated) to 565±7.07; 610±14.14; 607.5±17.68, and 612.5±10.61, respectively (150W-3 min; 150W-6 min; 375W-3 min and 375W-6 min). Egg’s whipping capacity values were increased with increasing exposure time and power (Watt). Sonication has a potential to become significant breakthrough and improve functional properties of eggs during storage while increasing shelf-life.

ÖZET:
Bu çalışmada, ultrases uygulamasının 150 W ve 375 W değerlerinde 3 ve 6 dakika sürede sıvı bütün yumurtanın fiziko-fonksiyonel kalite kriterlerine etkisi belirlenmiştir. Sıvı bütün yumurtanın pH, L*, a*, b* renk, köpük kapasitesi, köpük stabilitesi, ambalaj içi O2 ve CO2 gaz konsantrasyonu depolama süresince (4°C’de 5-6 hafta) ölçülmüştür. Ultrases uygulamasının yumurtanın kalite kriterlerinde; pH değerinde (7.37±0.04’den 7.46±0.02’e) artış ve depolamada CO2 konsantrasyonunda (35.50±0.10’den 17.43±0.32’e) azalma kaydedilmiştir. (375W-6 dk.). Çalışmada ultrases uygulaması, köpük kapasitesi değerleri üzerinde önemli düzeyde etki ederek; 410±14.14 (kontrol), uygulamalarda ise sırası ile; 565±7.07; 610±14.14; 607.5±17.68 ve 612.5±10.61 (150W-3 dk.; 150W-6 dk.; 375W-3 dk. ve 375W-6 dk.) değerleri belirlenmiştir. Uygulanan ultrases gücü ve uygulama süresinin artması ile birlikte yumurtaların köpük kapasitelerinin arttığı sonucuna ulaşılmıştır. Ultrasesin sıvı yumurtanın fizikofonksiyonel özellikleri üzerindeki etkisi incelendiğinde sonikasyon tekniğinin raf ömrünün arttırılması ve fonksiyonel özelliklerinin geliştirilmesi amacıyla kullanılabilme potansiyeli belirlenmiştir.

— Mechanical and thermo-analytical analysis carried out on the composites. In order to determine the relationships between structure and properties of composite, it is necessary to carry out different measurements. The tests were: tensile test, hardness test, thermal conductivity SEM, DSC and DMA. The results showed that the mixtures were inhomogeneous. The tensile and hardness test resulted that the composite has stronger structure and an increase in the strength values. From the thermo-analytical analysis the corn cob additive effect in the composite structure can be observed. The result of the DMA shows that the additive works as inactive filler, and does not change the glass transition temperature of the rigid PVC foam.

Foaming and filamentous bulking can affect some wastewater treatment plants continuously or seasonally. Here, the winter season filamentous species in KonyaWWTP were identified and associated with the operational conditions of the plant.Mainly Types 0041/0675, 021N, 0092, 1851, 0581, 0803, N. Limicola I, II, III, M.Parvicella; Zooglea, and Thiothrix II found to dominate, which represents the biodegradable industrial discharge, high θc and low F/M. In order to avoid the bulking/foaming problems, specific control measures should be preferred to non-specific ones. Low ambient temperature had not adverse affect in filamentous growth. Operational condiditons were more critical.

ABSTRACK
The present diploma thesis aim’s to contribute on the survey to the study of the production of metal foam by method of powder metallurgy, but also to record the theoretical calculation of basic mechanical models, thermal, electrical magnitudes of metal foams.
In the production of metal foams dominant for mechanical, thermal, electrical properties of the metal foams are the parent material and the alloy to be used must be made juxtaposition of material properties.
For this purpose, they record the basic properties of some materials used in powder metallurgy in the production of metal foams. Also crucial is the study of the size of the porous structure and the pore size as the porous type of cells to determine the size of the application and for the mechanical, thermal, electrical etc. properties of the produced foam.
Perform the recording of some basic methods of production of metallic foams in order to understand their preexisting production technique and the type foams creates each with the bibliographic record of the pore size distribution of these as well as the porosity that can be achieved.
Emphasis is given in producing metal foams by the process of powder metallurgy and in particular to methods a) foams by dissolved space holders after compression of mixture –space holder powders, removal of space holder and sintering, b) metal foams by a precursor produced by compressing a powder or more metals and foaming agent by heating near the melting point.
Reported and examines the factors that determine the production of such grain size powder treatment of the precursor, the compression pressure of the powders etc.
At the end of the theoretical part is given some financial data for costing and viability of different production methods of metallic foams.
The experimental part developed metal foam production of copper powder water dissolved space holder agent brown, white granulated sugar with specific proportions powders.
It consists of 5 rounds of experiments where the first produced three copper - brown sugar specimen which compressed into 3 different pressures while the same happened on specimens which containing white crystalline sugar. Reported failures and became their justification. Then the tests were limited to the pressure at which had the most satisfactory results with respect to the failure of the samples during the phase of compression. Further experiments in this list form the pressure of resources and the structure of the foams by use of binder in relation to the test pieces containing no binders. During the experiments we used a different puller to observe the effect that the successful compression of the test piece. Studied different powder residence times under load and useful conclusions were reached
Calculated on the optimal pressure, the macro porosity and the micro porosity of the foams binder ethanol and their relative density and detail using Imagej program to make correlation of the two results. then they were given the conclusions related to the whole experimental process in relation to the literature study resulting from the production process from copper metal foam compressed doing leaching and sintering.
Finally given fields for further research into the development of our knowledge on the properties, the optimum production, and the structure of metal foams by the method of powder metallurgy mainly for two technique of water-soluble agent and that of the precursor medium foaming agent.

The aim of this study was to examine interactions between whey proteins (whey protein isolate (WPI), whey protein concentrate (WPC) and β-lactoglobulin) and carbohydrates (glucose, sucrose, starch and inulin) on some physical and functional properties of whey proteins and carbohydrates suspensions (10% dry matter (w/v)).Model systems were therefore investigated related to their foam expansion and foam stability. Carbohydrate addition in model suspensions of whey proteins resulted in significantly (P < 0.05) enhanced foam stability of protein suspensions (FSI; MFS). Model systems were also analyzed for emulsion activity index (EAI) and emulsion stability index (ESI) by the turbidometric technique. EAI and ESI values increased significantly (P < 0.05) in model suspensions prepared with WPI and β-lactoglobulin in combination with mono and disaccharides, while significant decrease (P < 0.05) were remarked in model suspensions prepared with inulin and starch addition.The phase-transition temperatures of investigated model systems were determined using differential thermal analysis with continuous scanning. In all model suspensions, significant lowering (P < 0.05) of initial freezing temperature has occurred.

This study investigates the extrusion foaming behavior of high impact polystyrene (HIPS) through a twin-screw extruder using two various types of chemical blowing agents (CBA). The die temperature profile was firstly tailored during the foaming of HIPS for two different CBAs. Then the CBA content effect on the foaming behavior of HIPS was verified for both CBAs. The effect of screw speed (RPM) on the foaming behavior of HIPS was, subsequently, illustrated for both CBAs. It was found that the cell density and the void fraction of the HIPS foamed samples increased at the maximum CBA content of 5 wt% and the minimum screw RPM of 100. The HIPS extrusion foaming behavior was further investigated via blending it with general purpose PS (GPPS) at the blending ratios (wt%/wt%) of 75/25 and 50/50, as well as, via compounding HIPS with three different inorganic fillers (i.e., micro-lamellar talc, talc, and calcium carbonate) at three different contents (i.e., 1, 2, and 3 wt %). The increase in GPPS and inorganic filler contents increased the cell density and void fraction of HIPS foams while the inorganic filler type did not reveal much differences in the foaming results.

This study aimed to determine the effect of pretreating defatted soy flakes with ultrasound on soy protein isolate (SPI) yield and functionality. Defatted soy flakes dispersed into water (16%, w/w) were sonicated for 30, 60 and 120 s at ultrasonic amplitudes of 21 and 84 µmpp (peak to peak amplitude in µm), representing low and high power, respectively. The power densities were 0.30 and 2.56 W mL−1, respectively. The SPI yield increased by 13 and 34%, after sonication for 120 s at low and high power, respectively. The sonication of defatted soy flakes for 120 s at the higher power level improved the SPI solubility by 34% at pH 7.0, while decreasing emulsification and foaming capacities by 12 and 26%, respectively, when compared to control SPI. Rheological behavior of the SPI was also modified with significant loss in consistency coefficient due to sonication. Some of these results could be explained by the loss of the protein native state with increased sonication time and power.

Der Text handelt von einem Material, das luftig und leicht daherkommt und das sich gerade deshalb schwer fassen lässt – in praktischer wie theoretischer Hinsicht. Die Rede ist von fluiden Schäumen. Ein trivialeres und belangloseres Material scheint kaum zu existieren, denn flüssiger Schaum begegnet uns im Alltag laufend: beim Rasieren und Duschen, im Bier oder Cappuccino, bei der Zahnpflege, der Haarwäsche, beim Linsen kochen und Spülen des Geschirrs, bei der Autoreinigung und beim Wohnungsputz, beim Bereiten von Eischnee und so fort. Der Luftikus unter den Materialien wird wegen seiner vergänglichen Banalität und Nebensächlichkeit schnell übersehen. Doch obwohl es seine fragile und fast schwerelose Beschaffenheit nahelegen mag, ist liquider Schaum weder ein theoretisches Leichtgewicht noch ein Thema ohne Substanz. Vielmehr ist er im doppelten Wortsinne subtil: ein zartgliedriges, feines Gewebe aus unzähligen Bläschen, das auf den geringsten Windhauch mit einem Zittern reagiert, und eine knifflige Angelegenheit für das Denken des Materiellen. Fluide Schäume sind »Stoffe in Bewegung«, sie sind ›im Fluss‹ und kennen lediglich metastabile Zustände. Um ihrem prozessualen Charakter gerecht zu werden, bezeichne ich Schaumbildungen im Folgenden als aphrogene Produktionen. Der Begriff der Aphrogenese leitet sich vom griechischen Wort ›aphrós‹, zu Deutsch: Schaum, ab und verweist auf die dynamische Hervorbringung und die kontinuierlichen Transformationsvorgänge, die zum Lebenszyklus dieses ephemeren Materials gehören. Aphrogene Produktionen sind somit gewissermaßen ›Schaumgeburten‹, die wachsen und vergehen; sie sind Materialisierungen im Prozess.

This article compares the rheological, thermal, and foaming behaviors of various polylactide (PLA) grades supplied by NatureWorks and their compounds with three different fillers. The results depicted that linear PLAs with various D-content had similar viscoelastic behavior whereas branching and addition of additives improved PLA's complex viscosity and its elastic behavior. Strain hardening behavior was also observed only in PLA with branched structures. Increased complex viscosity due to the induced crystallization was also expedited in PLAs with lower D-content. Addition of chain extender and additives also expedited the crystallization rate and hence expedited the shear viscosity increase. Among the additives, micro-sized talc enhanced PLA's crystallization rate more effectively than the nano-sized additives due to its more dominant role on crystal growth than crystal nucleation that exist in PLAs with nanoparticles. Foam uniformity was however enhanced more significantly in PLAs with nanoparticles.

Al-6wt%Si alloy foam was prepared by melt foaming method with the addition of titanium hydride as a blowing agent. The effect of thermal decomposition properties of titanium hydride on the alloy melt foaming behavior and the pores structure was studied. The result shows that the number of pores in the foam with stirring time t s of 60 to 150 sec is 120 to 220 per unit area (cm−2). At the temperature of 550°C there is a uniform cell structure. The porosity of foamed Al-6wt%Si with TiH2 addition of 1.0 wt% has been remarkably increased, and 1.0 to 1.5 wt% provided a high uniformity of spherical porosity cell structure distribution besides having a favorable decrease in bulk density.

This study aimed to determine the effect of pretreating defatted soy flakes with ultrasound on soy protein isolate (SPI) yield and functionality. Defatted soy flakes dispersed into water (16%, w/w) were sonicated for 30, 60 and 120 s at ultrasonic amplitudes of 21 and 84 µmpp (peak to peak amplitude in µm), representing low and high power, respectively. The power densities were 0.30 and 2.56 W mL−1, respectively. The SPI yield increased by 13 and 34%, after sonication for 120 s at low and high power, respectively. The sonication of defatted soy flakes for 120 s at the higher power level improved the SPI solubility by 34% at pH 7.0, while decreasing emulsification and foaming capacities by 12 and 26%, respectively, when compared to control SPI. Rheological behavior of the SPI was also modified with significant loss in consistency coefficient due to sonication. Some of these results could be explained by the loss of the protein native state with increased sonication time and power.

Vegetable proteins are widely used in many food formulations due to their physico-chemical properties, low cost and availability. The main objective of this work is to study the chemical composition and properties of a protein concentrate of Pinus halepensis. Mill seeds (PHPC) and mainly to optimize the effect of pH, NaCl concentration and phosphate buffer (PB) molarity on functional properties (solubility, emulsifying activity index (EAI) and foaming capacity (FC)) of this concentrate by response surface methodology (RSM). The chemical composition was determined in terms of proteins, sugars, lipids, ash and moisture. The physico-chemical characteristics were studied by their water and oil holding capacity (OHC, WHC) and their surface hydrophobicity (SH). Finally, the functional properties of PHPC were studied in terms of solubility, EAI, FC, minimum gelling concentration (MGC) and finally heat coagulability (HC). A PHPC yield of 36.66 � 0.7% was obtained. The WHC and OHC was 3.89 g water/g PHPC and 3.54 g oil/g PHPC respectively and a SH of 87.09 � 0.78 was obtained. The optimization results showed that the optimal conditions for solubility, EAI and FC were: pH:10.88, NaCl:0 g/l, PB:0.078 M; pH:12, NaCl:0.55 g/l, PB:0.1M and pH:2, NaCl:0, PB:0 M respectively, having given a solubility of 87.13 � 0.14%, an EAI of 36.82 � 0.34 and a FC of 182.72. Then, the desirability of the three responses (solubility, EAI and FC) which was pH:12, NaCl: 0.55 g/l and PB of 0.1M was used to assess the stability of EAI and FC, to determine the MGC and HC. This study shows that Aleppo pine seeds are a good source of functional proteins, potentially applicable in the food industry and that pH, NaCl concentration and PB molarity have a major influence on functional properties.