scholarly journals Surface induced self-organization of comb-like macromolecules

2011 ◽  
Vol 2 ◽  
pp. 569-584 ◽  
Author(s):  
Konstantin I Popov ◽  
Vladimir V Palyulin ◽  
Martin Möller ◽  
Alexei R Khokhlov ◽  
Igor I Potemkin
Keyword(s):  
Ultrathin Films ◽  
Self Assembly ◽  
Self Organization ◽  
Side Chain ◽  
Spontaneous Curvature ◽  
Side Chains ◽  
Polymer Architectures ◽  
Different Types ◽  
Surface Domains ◽  
The Stability

We present a review of the theoretical and experimental evidence for the peculiar properties of comb copolymers, demonstrating the uniqueness of these materials among other polymer architectures. These special properties include an increase in stiffness upon increasing side-chain length, the spontaneous curvature of adsorbed combs, rod–globule transition, and specific intramolecular self-assembly. We also propose a theory of chemically heterogeneous surface nanopattern formation in ultrathin films of comblike macromolecules containing two different types (A and B) of incompatible side chains (so-called binary combs). Side chains of the binary combs are strongly adsorbed on a surface and segregated with respect to the backbone. The thickness of surface domains formed by the B side chains is controlled by the interaction with the substrate. We predict the stability of direct and inverse disc-, torus- and stripelike nanostructures. Phase diagrams of the film are constructed.

scholarly journals Amphiphilic Comb Polymers as New Additives in Bicontinuous Microemulsions

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2410
Author(s):  
Debasish Saha ◽  
Karthik R. Peddireddy ◽  
Jürgen Allgaier ◽  
Wei Zhang ◽  
Simona Maccarrone ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Amphiphilic Polymers ◽  
Side Chain ◽  
Side Chains ◽  
Contrast Variation ◽  
Dna Complexes ◽  
Comb Polymers ◽  
Polymer Architectures

It has been shown that the thermodynamics of bicontinuous microemulsions can be tailored via the addition of various different amphiphilic polymers. In this manuscript, we now focus on comb-type polymers consisting of hydrophobic backbones and hydrophilic side chains. The distinct philicity of the backbone and side chains leads to a well-defined segregation into the oil and water domains respectively, as confirmed by contrast variation small-angle neutron scattering experiments. This polymer–microemulsion structure leads to well-described conformational entropies of the polymer fragments (backbone and side chains) that exert pressure on the membrane, which influences the thermodynamics of the overall microemulsion. In the context of the different polymer architectures that have been studied by our group with regards to their phase diagrams and small-angle neutron scattering, the microemulsion thermodynamics of comb polymers can be described in terms of a superposition of the backbone and side chain fragments. The denser or longer the side chain, the stronger the grafting and the more visible the brush effect of the side chains becomes. Possible applications of the comb polymers as switchable additives are discussed. Finally, a balanced philicity of polymers also motivates transmembrane migration in biological systems of the polymers themselves or of polymer–DNA complexes.

Synthesis and self-assembly behaviours of side-chain smectic thiol–ene polymers based on the polysiloxane backbone

2016 ◽  
Vol 4 (7) ◽  
pp. 1425-1440 ◽  
Author(s):  
Wenhuan Yao ◽  
Yanzi Gao ◽  
Xiao Yuan ◽  
Baofeng He ◽  
Haifeng Yu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Click Chemistry ◽  
Self Assembly ◽  
Side Chain ◽  
Liquid Crystal Polymers ◽  
Different Types

A series of novel chiral polysiloxane side chain liquid crystal polymers (PSCLCPs) with two different types of LC phases and three self-assembly arrangements were successfully synthesized via thiol–ene click chemistry.

scholarly journals Engineering the residual side chains of HAP phytases to improve their pepsin resistance and catalytic efficiency

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Canfang Niu ◽  
Peilong Yang ◽  
Huiying Luo ◽  
Huoqing Huang ◽  
Yaru Wang ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Catalytic Efficiency ◽  
Site Directed Mutagenesis ◽  
Side Chain ◽  
Side Chains ◽  
Cleavage Sites ◽  
Corn Meal ◽  
Feed Enzymes ◽  
The Stability ◽  
Phytate Content

Abstract Strong resistance to proteolytic attack is important for feed enzymes. Here, we selected three predicted pepsin cleavage sites, L99, L162, and E230 (numbering from the initiator M of premature proteins), in pepsin-sensitive HAP phytases YkAPPA from Yersinia kristensenii and YeAPPA from Y. enterocolitica, which corresponded to L99, V162, and D230 in pepsin-resistant YrAPPA from Y. rohdei. We constructed mutants with different side chain structures at these sites using site-directed mutagenesis and produced all enzymes in Escherichia coli for catalytic and biochemical characterization. The substitutions E230G/A/P/R/S/T/D, L162G/A/V, L99A, L99A/L162G, and L99A/L162G/E230G improved the pepsin resistance. Moreover, E230G/A and L162G/V conferred enhanced pepsin resistance on YkAPPA and YeAPPA, increased their catalytic efficiency 1.3–2.4-fold, improved their stability at 60 °C and pH 1.0–2.0 and alleviated inhibition by metal ions. In addition, E230G increased the ability of YkAPPA and YeAPPA to hydrolyze phytate from corn meal at a high pepsin concentration and low pH, which indicated that optimization of the pepsin cleavage site side chains may enhance the pepsin resistance, improve the stability at acidic pH, and increase the catalytic activity. This study proposes an efficient approach to improve enzyme performance in monogastric animals fed feed with a high phytate content.

Precise polyethylene derivatives bearing mesogenic side-chains: delicate self-assembly depending on graft density

2020 ◽  
Vol 11 (8) ◽  
pp. 1454-1461 ◽  
Author(s):  
Wen-Ying Chang ◽  
Dong Shi ◽  
Xu-Qiang Jiang ◽  
Jia-Di Jiang ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Self Assembly ◽  
Spacing Effect ◽  
Spatial Arrangement ◽  
Side Chain ◽  
Side Chains ◽  
Local Coupling ◽  
Graft Density

Precise polyethylene derivatives bearing mesogenic side-chains demonstrate a sophisticated side-chain spacing effect on the local coupling and spatial arrangement of the backbone and side-chains.

Effects of side chains of oxatub[4]arene on its conformational interconversion, molecular recognition and macroscopic self-assembly

2017 ◽  
Vol 53 (93) ◽  
pp. 12572-12575 ◽  
Author(s):  
Liu-Pan Yang ◽  
Fei Jia ◽  
Fangfang Pan ◽  
Zhi-Sheng Pan ◽  
Kari Rissanen ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Chain Length ◽  
Self Assembly ◽  
Side Chain ◽  
Side Chains ◽  
Side Chain Length ◽  
Conformational Interconversion ◽  
Assembly Behavior

The side-chain length of oxatub[4]arenes was shown to affect its conformational interconversion, molecular recognition and macroscopic self-assembly behavior.

Hierarchical superstructures of norbornene-based polymers depending on dendronized side-chains

2016 ◽  
Vol 7 (33) ◽  
pp. 5304-5311 ◽  
Author(s):  
Dae-Yoon Kim ◽  
Dong-Gue Kang ◽  
Suyong Shin ◽  
Tae-Lim Choi ◽  
Kwang-Un Jeong
Keyword(s):  
Self Assembly ◽  
Ring Opening ◽  
Main Chain ◽  
The Self ◽  
Side Chain ◽  
Side Chains ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Main Chain Polymers

For understanding the self-assembly behaviours of norbornene-based main-chain polymers depending on side-chain pendants, a series of polynorbornenes containing the programmed dendrons is newly designed and successfully synthesized via ring opening metathesis polymerization.

Influence of side-chain interactions on the self-assembly of discotic tricarboxyamides: a crystallographic insight

RSC Advances ◽  
2015 ◽  
Vol 5 (40) ◽  
pp. 31845-31851 ◽  
Author(s):  
Arpita Paikar ◽  
Apurba Pramanik ◽  
Debasish Haldar
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Side Chain ◽  
Side Chains ◽  
Fiber Network

Side chains interactions promote the self-assembly of discotic tricarboxyamides to form an entangled fiber network and thermo responsive gel.

Phase Transitions in Polymers Containing Long Self-Assembled CH2 Sequences in the Side Chain: A Positron Lifetime Study

2010 ◽  
Vol 666 ◽  
pp. 71-74 ◽  
Author(s):  
Yang Yu ◽  
Günter Dlubek ◽  
Reinhard Krause-Rehberg ◽  
Mario Beiner ◽  
Elke Hempel
Keyword(s):  
Self Assembly ◽  
Positron Lifetime ◽  
Side Chain ◽  
Strong Increase ◽  
Side Chains ◽  
Reverse Effect ◽  
Alkyl Methacrylate ◽  
Short Side ◽  
The Mean ◽  
Hexyl Methacrylate

Positron lifetime annihilation spectroscopy (PALS) was used to study the temperature- dependence of sub-nanometer size local free volumes in two atactic poly(n-octadecyl methacrylate)s (PODMA) with different molecular weight. These materials exhibit short range layered structure with a self-assembly and crystallization of side chains. From the ortho-positronium (o-Ps) lifetime the size of free volume holes and its distribution are calculated. At a temperature Tm=311 ± 5 K, the mean hole volume <vh> shows an abrupt and strong increase from 0.15 nm3 to 0.2 nm3, which comes from the melting of side-chains. The reverse effect, attributed to side chain crystallization, was observed during cooling the samples at slightly lower temperatures. The lifetime result of PODMA is compared with semifluorinated polyesters in which the side chain has an oxydecylperfluorodecyl structure (-O-(CH2)10-(CF2)9-CF3). Long chain polymers without side-chains such as polyethylene and short side-chain poly(n-alkyl methacrylate)s: poly(methyl methacrylate) (PMMA) and poly(n-hexyl methacrylate) (PHMA) are also compared with these polymers.

Side chain position, length and odd/even effects on the 2D self-assembly of mono-substituted anthraquinone derivatives at the liquid/solid interface

RSC Advances ◽  
2015 ◽  
Vol 5 (113) ◽  
pp. 93337-93346 ◽  
Author(s):  
Yi Hu ◽  
Kai Miao ◽  
Bao Zha ◽  
Xinrui Miao ◽  
Li Xu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Side Chain ◽  
Side Chains ◽  
Solid Interface ◽  
Anthraquinone Derivatives ◽  
Self Assembled

This work provides efficient methods for regulating self-assembled structures by changing the position, length and odd/even properties of the side chains.

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