Nanopatterning in Langmuir-Blodgett monolayers of a thermoresponsive double hydrophilic block copolymer studied by atomic force microscopy.
The microphase-separation of Langmuir-Blodgett (LB) monolayers of a rhodamine B (RhB) end-labeled double hydrophilic block copolymer (DHBC), RhB-Poly(N,N-dimethylacrylamide)-b-poly(N,N-diethylacryl-amide) (RhB-PDMA(207)b-PDEA177) and the 1:1 segmental mixture of PDEA and RhB-PDMA homopolymers was followed by AFM. The DHBC LB films revealed a loose distribution of nano-aggregates with variable geometries below the lower critical solution temperature (LCST) of PDEA (32 degrees C) and low surface pressure (3 mN m(-1)). By increasing either the temperature above the LCST of PDEA or the surface pressure beyond the immersion regime of PDMA in the subphase (7 mN m(-1)) a dense nanopatterning was obtained. The absence of a corresponding regular nanopatterning in LB films of mixed homopolymers with the same composition highlights the role of the covalent bonding between PDEA and PDMA on the self-segregation of the two blocks at the air-water interface.
Interaction of a double hydrophilic block copolymer with lipid monolayers at the air–water interface
The interaction of poly(N,N-dimethylacryl-amide)-b-poly(N,N-diethylacrylamide) (PDMA207-b-PDEA177), (DHBC), with 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (sodium salt) (DPPG) and stearic acid (SA), was investigated at the air–water interface. The π − A isotherms of DHBC/DPPC and DHBC/DPPG binary mixtures are nearly the sum of the contribution of components weighted by the molar composition, — the additive rule. The π − A curves of the mixtures show a plateau at ~ 7 mN m− 1, owing to the immersion of the hydrophilic block PDMA, and other at ~ 27 mN m− 1 attributed to the immersion of the less hydrophilic PDEA block. Differently, the binary mixtures of DHBC/SA and PDEA homopolymer/SA do not follow the additive rule of the components showing an expanding effect at low surface pressures. Brewster angle microscopy images show that both DHBC and PDEA polymers interact with lipid monolayers, strongly disturbing their morphology.
CNC Desktop Vertical Machining Bench Design and Cooling Fluid Application
Today's manufacturing technologies, the human work force is used and at least a minimum level of margin of error is used in CNC machines. Desktop CNC machine tools and CNC machine tools are developed in parallel with the development of personal computers. This study provides CNC training institutions for education, small and medium-sized enterprises for commercial purposes use the low-cost desktop machine has been designing and manufacturing of CNC vertical machining was carried out. Desktop CNC machine tools and production capacity to handle the kind of material was applied to increase the cooling fluid. Through A199 and Fe37 the cooling fluid application desktop CNC machine tools, such as processing of materials that are difficult to successfully processed. Keywords—CNC, Desktop CNC Machine, CNC Design