scholarly journals Neuron-like tubule extension of giant polymer vesicles

2021 ◽  
Vol 3 (1) ◽  
pp. 195-202
Author(s):  
Eri Yoshida ◽  
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Methacrylic Acid ◽  
Diblock Copolymers ◽  
Size Structure ◽  
Early Stage ◽  
Monomer Conversion ◽  
Morphological Transformation ◽  
Polymer Vesicles ◽  
Spherical Vesicles

Giant polymer vesicles consisting of amphiphilic diblock copolymers are helpful as artificial biomembrane models based on many similarities in their size, structure, morphological transformation, membrane permeability, etc. This paper describes the creation of neuron-like tubule extension employing the polymer vesicles. The polymerization-induced self-assembly was performed in the presence of micron-sized spherical vesicles consisting of poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid), PMAA-b-P(MMA-r-MAA), through the photo nitroxide-mediated controlled/living radical polymerization (photo-NMP) using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO) as the mediator. The photo-NMP of methyl methacrylate (MMA) and methacrylic acid (MAA) was carried out in an aqueous methanol solution (CH3OH/H2O = 3/1 v/v) using poly(methacrylic acid) (PMAA) end-capped with MTEMPO and the spherical vesicles of PMAA141-b-P(MMA0.831-r-MAA0.169)368 with an 11.7-mm diameter. The vesicles projected many processes on their surface during the early stage of the polymerization. As the polymerization progressed, only one or two of the processes extended to thick tubules, accompanied by the slow growth of thin tubules. Further progress of the polymerization elongated the thick tubules and caused branching of the tubules. The tubules had a vesicular structure because cup-like vesicles joined in line were formed during the initial stage of the extension. The polymerization livingness supported the tubule extension based on a linear increase in the molecular weight of the component copolymer and a negligible change in the molecular weight distribution versus the monomer conversion. The spherical vesicles were similar to the neurons in the tubule extension for the initial projection, followed by the elongation and branching. This similarity implies that the neurite extension in the neurons is related to the inherent property of the bilayer membrane.

scholarly journals Human Erythrocyte-Like Transformation of Synthetic Polymer Vesicles

2021 ◽  
Author(s):  
Eri Yoshida
Keyword(s):  
Methacrylic Acid ◽  
Human Erythrocyte ◽  
Bilayer Membrane ◽  
Synthetic Polymer ◽  
Butyl Methacrylate ◽  
Temperature Changes ◽  
Polymer Vesicles ◽  
Membrane Perforation ◽  
Response To Temperature ◽  
Spherical Vesicles

Abstract This paper describes that synthetic polymer vesicles undergo a human erythrocyte-like transformation in response to temperature changes. The normally biconcave discoid erythrocytes, i.e., the discocytes, are transformed into various shapes by their environmental stresses. Field emission scanning electron microscopy (FE-SEM) demonstrates that the spherical vesicles consisting of poly(methacrylic acid)-block-poly(n-butyl methacrylate-random-methacrylic acid), PMAA-b-P(BMA-r-MAA), transform into echinocyte-like crenate vesicles due to expansion by the component copolymers in being freed from the vesicle surface when heated in an aqueous methanol solution. An increase in the vesicle concentration transforms the spherical vesicles into stomatocyte-like cup-shaped vesicles via the membrane perforation or double invaginations followed by membrane coupling and fusion. Light scattering studies reveal the reversibility and repeatability of the transformations. These findings indicate that the erythrocyte transformations are attributed to the inherent property of the bilayer membrane. The polymer vesicles are helpful for a better understanding of the biomembrane.

scholarly journals Optimal Control of Non-Isothermal, Batch Polymerization of Methacrylates with Specified Time, Monomer Conversion, and Average Molecular Weights

2021 ◽  
Author(s):  
Baranitharan Sanmuga Sundaram
Keyword(s):  
Molecular Weight ◽  
Optimal Control ◽  
Methyl Methacrylate ◽  
Process Model ◽  
Control Method ◽  
Operation Time ◽  
Monomer Conversion ◽  
Butyl Methacrylate ◽  
Solution Polymerization ◽  
Polymer Molecular Weight

Optimal control policies are determined for the free radical polymerization of three different polymerization processes, in a non-isothermal batch reactor as follows: (1) bulk polymerization of n-butyl methacrylate; (2) solution polymerization of methyl methacrylate with monofunctional initiator; (3) solution polymerization of methyl methacrylate with bifunctional initiator. Four different optimal control objectives are realized for the above three processes. The objectives are: (i) maximization of monomer conversion in a specified operation time, (ii) minimization of operation time for a specified, final monomer conversation, (iii) maximization of monomer conversion for a specified, final number average polymer molecular weight, and (iv) maximization of monomer conversion for a specified, final weight average polymer molecular weight. The realization of these objectives is expected to be very useful for the batch production of polymers. To realize the above four different optimal control objectives, a genetic algorithms-based optimal control method is applied, and the temperature of heat exchange fluid inside reactor jacket is used as a control function. Necessary equations are provided in the above three processes to suitably transform the process model in the range of a specified variable other than time, and to evaluate the elements of Jacobian to help in the accurate solution of the process model. The results of this optimal control application reveal considerable improvements in the performance of the batch polymerization processes.

scholarly journals Analytical strategy for the molecular weight determination of random copolymers of poly(methyl methacrylate) and poly(methacrylic acid)

2010 ◽  
Vol 21 (6) ◽  
pp. 1075-1085 ◽  
Author(s):  
Rémi Giordanengo ◽  
Stéphane Viel ◽  
Manuel Hidalgo ◽  
Béatrice Allard-Breton ◽  
André Thévand ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Methacrylic Acid ◽  
Random Copolymers ◽  
Molecular Weight Determination ◽  
Analytical Strategy ◽  
Poly Methyl Methacrylate

scholarly journals Optimal Control of Non-Isothermal, Batch Polymerization of Methacrylates with Specified Time, Monomer Conversion, and Average Molecular Weights

2021 ◽  
Author(s):  
Baranitharan Sanmuga Sundaram
Keyword(s):  
Molecular Weight ◽  
Optimal Control ◽  
Methyl Methacrylate ◽  
Process Model ◽  
Control Method ◽  
Operation Time ◽  
Monomer Conversion ◽  
Butyl Methacrylate ◽  
Solution Polymerization ◽  
Polymer Molecular Weight

Optimal control policies are determined for the free radical polymerization of three different polymerization processes, in a non-isothermal batch reactor as follows: (1) bulk polymerization of n-butyl methacrylate; (2) solution polymerization of methyl methacrylate with monofunctional initiator; (3) solution polymerization of methyl methacrylate with bifunctional initiator. Four different optimal control objectives are realized for the above three processes. The objectives are: (i) maximization of monomer conversion in a specified operation time, (ii) minimization of operation time for a specified, final monomer conversation, (iii) maximization of monomer conversion for a specified, final number average polymer molecular weight, and (iv) maximization of monomer conversion for a specified, final weight average polymer molecular weight. The realization of these objectives is expected to be very useful for the batch production of polymers. To realize the above four different optimal control objectives, a genetic algorithms-based optimal control method is applied, and the temperature of heat exchange fluid inside reactor jacket is used as a control function. Necessary equations are provided in the above three processes to suitably transform the process model in the range of a specified variable other than time, and to evaluate the elements of Jacobian to help in the accurate solution of the process model. The results of this optimal control application reveal considerable improvements in the performance of the batch polymerization processes.

The Characteristic Research of Two Kinds of Block Polymer

2011 ◽  
Vol 356-360 ◽  
pp. 74-77
Author(s):  
Qing Bo Yu ◽  
Xian Hua Li ◽  
Yu Lun Tao ◽  
Guo Jun Cheng
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Methyl Acrylate ◽  
Diblock Copolymers ◽  
Triblock Copolymers ◽  
Glycidyl Ether ◽  
Monomer Conversion ◽  
Block Polymer ◽  
Allyl Glycidyl Ether ◽  
Living Free Radical Polymerization

Dual end and single end MacroRAFT agents of polystyrene were obtained respectively by polymerizations of styrene in the presence of benzyl 1H-imidazole-1- carbodithioate (BICDT) and 4,4‘-bis(imidazole-1-carbodithioatemethyl)biphenyl (ICTMP) via the thermal initiation. Then copolymerization of allyl glycidyl ether（AGE） with methyl acrylate（MA） was performed to prepare the functional block copolymers in the presence of PSt maeorRATF agents. The results show that the process has good characteristics of living free radical polymerization. However, the top monomer conversion of triblock copolymers comparing diblock copolymers is lower under the same theory molecular weight and the content of monomer.

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