Hydrophilic modification

Molecular hybrids between organic polymers and silica gel are expected to show many possibilities as new composite materials. First, the hybrids may show intermediate properties between plastics and glasses (ceramics). In addition, the composition of the hybrids can be widely varied. In other words, the hybrids can be used to modify the organic polymer materials or to modify the inorganic glassy materials. The hydrophilic modification as described before is a typical example. 

Qiao X, Zhang Z, Ping Z (2007) Hydrophilic modification of ultrafiltration membranes and their application in Salvia miltiorrhiza decoction. Separ Purif Technol 56 265-269... 

In general all of these materials are hydrophobic although some hydrophilic modifications are known. Commercial hydrophilic variants, known as polyactive and shown in Figure 2, are composed of blocks of poly(butylene teraphthlate) and poly(ethylene oxide). 

Polyvinylidene-difluoride Low non-specific adsorption Dry autoclavable Good solvent compatibility Moderate flow rate and total throughput Hydrophobic base, made hydrophilic by chemical surface treatment may lose hydrophilic modification due to chemical attack High-cost filter material... 

Whereas the polyketones were usually reported to precipitate from the aqueous phase, under emulsion conditions latexes of ethylene-undecenoic acid-CO ter-polymers and of 1-alkene-CO copolymers can be obtained, which are film-forming at room temperature [12]. Using a miniemulsion technique (cf. Section 6.12.3), water-insoluble diphosphine ligands can be employed without the necessity for hydrophilic modification. 

Silica gel may also be modified with hydrophilic groups that are attached using short-chain nonpolar spacers. Hydrophilic modifications with polar groups include amino, cyano, and diol functionalities. Amino-SG offers weakly basic ion-exchange properties diol-SG considerably less affinity for water when compared with unmodified SG-60. These HPTLC materials offer increased selectivity for complex separations of biomolecules and drugs. 

Fig. 2.13 Size conservation of colloidal Pt/Ru particles under the hydrophilic modification of the (CH3)3-AI-acac protecting shell using polyethylene glycol-dodecylether(er/ 35(r)). A good solubility can be observed >100mg/AT metal in aromatics, hydrocarbons, ethers, alcohols, ketones, and water.

M.-L. Luo, J.-Q. Zhao, W. Tang, and C.-S. Pu. Hydrophilic modification of poly(ether sulfone) ultrafiltralion membrane surface by self-assembly of Ti02 nanoparticles. AppZ. Surf. ScL, 249(l-4) 76-84, August 2005. 

Goldmann et al. [31] introduced azido groups using thiol-alkene method through 1-azido-undecan-l 1-thiol first, then the point-and-click reaction of alkyle functionalized poly-2-hydroxyethanyl acrylate and azido groups to achieve the hydrophilic modification of polydivinylbenzene microspheres. 

Yi, Z., Zhu, L.-R, Zhao, Y.-F., Zhu, B.-K., andXn, Y.-Y. 2012. An extending of candidate for the hydrophilic modification of polysulfone membranes from the compatibihty consideration The polyethersulfone-based amphiphihc copolymer as an example. Journal of Membrane Science 390-391 48-57. 

Yang, P. Deng, J. Y. Yang, W. T. (2003). Confined photo-catalytic oxidation a fast surface hydrophilic modification method for polymeric materials. Polymer, Vol. 44, pp. 7157-7164, ISSN 0032-3861. 

In a series of our investigations on the surface reaction of fluorocarbon polymers, we found an effective hydrophilic modification for PTFE surface. We have studied the reactivity on the films with hydrazine (N2H4), ammonia (NH3), and hydrogen peroxide (H2O2) which are excited upon irradiation with excimer lasers. The most effective modification to a hydrophilic surface was achieved with the ArF laser irradiation of the films in a hydrazine gas atmosphere. 

By the laser treatment, the surface of PTFE films could be made hydrophilic and the surface energy increased in comparison with that of a native PTFE film. As the results, we intended to extend the hydrophilic modification technique into metallization on the PTFE film by using a chemical (electroless) plating technique. If the activators for the plating will deposit only on the hydrophilic region, area-selective metallization will be performed on the surface of PTTE films modified upon the laser-irradiation through a mask by a projection method. 

Wavhal, D.S. and Fisher, E.R. 2002. Hydrophilic modification of polyethersulfone membranes by low temperature plasma-induced graft polymerization. 209 255-269. 

Zhang, M., Nguyen, Q.T. and Ping, Z. 2009. Hydrophilic modification of poly(vinylidene fiuoride) microporous membrane. 327 78-86. 

Wang, R. Yang, Y.-L. Qin, M. Wang, L.-K. Yu, L. Shao, B. Qiao, M.-Q. Wang, C. Feng, X.-Z., Biocompatible Hydrophilic Modifications of Poly(dimethylsiloxane) Using Self-Assembled Hydrophobins. Chem. Mater. 2007,19, 3227-3231. 

Sun, H., et al., 2015. Synthesis of well-defined amphiphilie block copolymers via AGET ATRP used for hydrophilic modification of PVDF membrane. Journal of Applied Polymer Science. 132(24) n/a-n/a. 

Hydrophilic modification of the membrane surface is also a promising method to control membrane fouling because the surface properties of membranes dominate the membrane characteristics. Plasma treatment is a widely used and effective technique to create polar organic functional groups on the membrane surface. Membrane hydrophilicity can be drastically improved by plasma treatment using various gases such as NH3 and CO2, and plasma treated membranes show better filtration performance and antifouling characteristics compared with unmodified ones (Yu et al., 2005). 

Sunmiarizing, the application of the preswelling grafting technique to the hydrophilic modification of polyetherurethane tubes leads to grafted products with a well defined hydrogel content at the surface. By keeping the grafting yield low, the mechanical properties... 

Xiang T, Yue WW, Wang R, Liang S, Sun SD, Zhao CS. Surface hydrophilic modification of polyethersulfone membranes by surface-initiated ATRP with enhanced blood compatibility. Colloids Surf B Biointerfaces 2013 110 15-21. 

The recently introduced hydrophilic modified precoated plates have broadened the spectrum of selectivity available for TLC. These plates are referred to as HPTLC-NH2 precoated plates, in which > -aminopropyl groups are bonded to the surface of a silica-gel skeleton, and HPTLC-CN precoated plates. with cyanopropyl moieties as the functional groups. In terms of polarity the two hydrophilic modifications can be classified as follows Normal Si02 > NH2 > CN > RP. Since the surface NHv and CN groups are of medium polarity, no wetting problems are encountered with the corresponding plates even at the maximum level... 

Chitosan based self assembled/amphiphilic NPs plays a vital role in delivery of number of drugs, nucleic acids and metals. Recently, the effects of hydrophobic and hydrophilic modifications on gene delivery of amphiphilic chitosan based nanocarriers investigated and it has been observed that this type of modification allowed the improved gene delivery via amphiphilic nanoparticles [128]. It was reported that the chitosan-based self-assembled nanoparticles can be readily obtained by chemically attaching the hydrophobic moiety to the backbone of chitosan and its derivatives, as shown in Fig. 3.5. These self-assembled nanoparticles can circulate in the... 

---