Measurement of cloud point temperature in polymer solutions

Mannella, G. A.; Carrubba, Vincenzo La; Brucato, V.

doi:10.1063/1.4816646

Cited by 15 publications

(5 citation statements)

References 30 publications

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“…Grayscale histograms were obtained for a pre-defined rectangular area of the image (see Figure 1, It is worthwhile noting that demixing temperatures were additionally measured on cooling at 1, 5, 10, and 20 K min -1 . This, however, led only to a minor decrease of the transition temperature with increasing cooling rate; dissolution temperatures obtained on subsequent heating revealed the expected demixing/dissolution hysteresis [22,34,35].…”

Section: Materials and Preparationmentioning

confidence: 91%

Phase behavior of the polymer/drug system PLA/DEET: Effect of PLA molar mass on subambient liquid-liquid phase separation

et al. 2018

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The phase behavior of binary mixtures of non-crystallizable racemic poly (D, L-lactic acid) (PDLLA) and the mosquito-repellent/drug N,N-diethyl-3-methylbenzamide (DEET) was analyzed with respect to the effect of the polymer molar mass on the liquid-liquid (L-L) phase separation characteristics, by cloud-point measurements and differential scanning calorimetry. The PDLLA/DEET system shows a subambient upper critical solution temperature (UCST), with the critical temperature decreasing and critical polymer concentration increasing with decreasing molar mass of PDLLA. The obtained L-L phase separation curves were used to estimate the temperature-dependence of the interaction parameter, confirming that the enhanced miscibility of the system components in case of low molar mass PDLLA is due to increased entropy of mixing.

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Section: Materials and Preparationmentioning

confidence: 91%

Phase behavior of the polymer/drug system PLA/DEET: Effect of PLA molar mass on subambient liquid-liquid phase separation

et al. 2018

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“…Often the cloud point detection is determined visually ; however, this method is not fully quantitative. A more precise way to carry out turbidity measurement is to adopt light transmission detection methods . For ternary polymer solutions, usually the cloud point curves are represented in a

T - w_{normalP}

plane, where w P is the polymer weight fraction and the solvent/nonsolvent ratio is taken as a constant parameter.…”

Section: Introductionmentioning

confidence: 99%

Evidence of mechanisms occurring in thermally induced phase separation of polymeric systems

Mannella

Pavia

Conoscenti

et al. 2014

J Polym Sci B Polym Phys

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Thermally induced phase separation is a fabrication technique for porous polymeric structures. By means of easy‐to‐tune processing parameters, such as system composition and demixing temperature, a vast latitude of average pore dimensions, pore size distributions, and morphologies can be obtained. The relation between demixing temperature and morphology was demonstrated via cloud point curve measurement and foams fabrication with controlled thermal protocols, for the model system poly‐l‐lactide–dioxane–water. The morphologies obtained at a temperature lower than cloud point showed a closed‐pore architecture, suggesting a “nucleation‐and‐growth” separation mechanism, which produced larger pores at higher holding times. Conversely, the porous structures attained when holding the sample above the cloud point exhibited open pores with dimensions independent of time, denoting a phase separation occurring during sample freezing. Finally, the influence of the cooling rate on final morphology was investigated, showing a clear correlation with microstructure and pore size. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 979–983

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Section: Resultsmentioning

confidence: 99%

“…Thus, density for each phase could not be determined, like optical beam devices that are used to detect phase transition, where it is also not possible to measure each phase absorbance, but the whole mixture turbidity.) 107,108 Thus, ρ variations with temperature and α T calculated for {PPG 400 or PE62 or L35 or PEG 400 } (1) + water (2) systems with w 1 = 0.15 are shown in Table 6 and Figure 7b and 10c, respectively.…”

Section: Resultsmentioning

confidence: 99%

Density, Refractive Index, pH, and Cloud Point Temperature Measurements and Thermal Expansion Coefficient Calculation for PPG₄₀₀, PE62, L64, L35, PEG₄₀₀, PEG₆₀₀, or PEG₁₀₀₀ + Water Systems

et al. 2021

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Thermophysical properties and phase behavior of seven {polymer (1) + water (2)} systems were determined using PPG 400 , Ultraric PE62, Pluronic L64, Pluronic L35, PEG 400 , PEG 600 , and PEG 1000 . Density (ρ) and refractive index (n) were measured for the whole range of w 1 at T = 293.2 K. Correlation with Redlich−Kister equation and prediction with Lorentz−Lorenz theoretical model were done. pH was measured for different mass fractions at ambient temperature (T ≈ 298.2 K). Cloud point temperature (T cloud ) was measured for different polymer mass fractions (w 1 ) from 0.02 up to 0.30. The thermal expansion coefficient (α T ) was calculated for w 1 = 0.15 and temperature (T) from 278.2 up to 348.2 K. Experiments were conducted at atmospheric pressure (P ≈ 95 kPa). The obtained thermophysical properties indicate that PEGs + water have the highest ρ while PPG 400 + water has the smallest ρ. Also, all ρ vs w 1 curves present a maximum value. n profiles are similar for all systems, showing the same refractive index increment for w 1 below 0.4. Density (Δρ) and refractive index (Δn) deviations are higher for the PPG 400 + water system, mainly due to the highest propylene content and hydrophobic character of PPG units. Moreover, pH varies with polymer mass fraction reaching a minimum value, probably because polymers release H + in solution. Phase transition results indicate that Tcloud and α T present related behaviors, i.e., when solution became turbid, α T shows an abrupt change in slope.

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Measurement of cloud point temperature in polymer solutions

Cited by 15 publications

References 30 publications

Phase behavior of the polymer/drug system PLA/DEET: Effect of PLA molar mass on subambient liquid-liquid phase separation

Phase behavior of the polymer/drug system PLA/DEET: Effect of PLA molar mass on subambient liquid-liquid phase separation

Evidence of mechanisms occurring in thermally induced phase separation of polymeric systems

Density, Refractive Index, pH, and Cloud Point Temperature Measurements and Thermal Expansion Coefficient Calculation for PPG₄₀₀, PE62, L64, L35, PEG₄₀₀, PEG₆₀₀, or PEG₁₀₀₀ + Water Systems

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Measurement of cloud point temperature in polymer solutions

Cited by 15 publications

References 30 publications

Phase behavior of the polymer/drug system PLA/DEET: Effect of PLA molar mass on subambient liquid-liquid phase separation

Phase behavior of the polymer/drug system PLA/DEET: Effect of PLA molar mass on subambient liquid-liquid phase separation

Evidence of mechanisms occurring in thermally induced phase separation of polymeric systems

Density, Refractive Index, pH, and Cloud Point Temperature Measurements and Thermal Expansion Coefficient Calculation for PPG400, PE62, L64, L35, PEG400, PEG600, or PEG1000 + Water Systems

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Density, Refractive Index, pH, and Cloud Point Temperature Measurements and Thermal Expansion Coefficient Calculation for PPG₄₀₀, PE62, L64, L35, PEG₄₀₀, PEG₆₀₀, or PEG₁₀₀₀ + Water Systems