Yicai Wu,Zijie Mao,Xianxian Qin,Kun Jiang,Xian-Yin Ma,Tian-Wen Jiang,Wen-Bin Cai
Triblock Pluronics of polyoxyethylene (PEO) and polyoxypropylene (PPO) are identified as competent suppressors for copper (Cu) electroplating in advanced electronics manufacturing. However, the specific interfacial roles of PEO and PPO blocks in Pluronic suppressors, are not yet fully understood, which is crucial for the rational design of effective suppressors. Herein, the influences of composition and block arrangement of such Pluronics on the inhibition against Cu plating are systematically investigated. The decrease in Cu deposition mass with increasing PPO content suggests that the PPO blocks are the main contributor to the inhibition strength of Pluronics, as demonstrated by the positive correlation between electrodeposited Cu mass and hydrophilic-lipophilic balance (HLB) value. Comparative analysis of normal and reverse Pluronic pairs with similar compositions indicates that an adequately long PEO block is indispensable to maintain the inhibition stability of Pluronics. Moreover, electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) offers direct evidence that the PEO block, rather than the PPO block, compactly adsorbs on the chloridion (Cl − ) adlayer covered Cu surface. This work highlights the importance of balancing the PPO-dominated inhibition strength and the PEO-dominated inhibition stability in the design of practical copolymer suppressors, for which the HLB may serve a valuable indicator, together with the PEO block length.
Inspired by marine mussel adhesive proteins, polymers with catechol side groups have been extensively explored in industrial and academic research. Here, Pluronic L-31 alcoholate ions were used as the initiator to prepare a series of polypeptide–Pluronic–polypeptide triblock copolymers via ring-opening polymerization of l-DOPA-N-carboxyanhydride (DOPA-NCA), l-arginine-NCA (Arg-NCA), l-cysteine-NCA (Cys-NCA), and ε-N-acryloyl lysine-NCA (Ac-Lys-NCA). These copolymers demonstrated good biodegradability, biocompatibility, and thermoresponsive properties. Adhesion tests using porcine skin and bone as adherends demonstrated lap-shear adhesion strengths up to 106 kPa and tensile adhesion strengths up to 675 kPa. The antibleeding activity and tissue adhesive ability were evaluated using a rat model. These polypeptide–Pluronic copolymer glues showed superior hemostatic properties and superior effects in wound healing and osteotomy gaps. Complete healing of skin incisions and remodeling of osteotomy gaps were observed in all rats after 14 and 60 days, respectively. These copolymers have potential uses as tissue adhesives, antibleeding, and tissue engineering materials.
Yang Zhang,Siru Zhou,Zhenglei Li,Haoquan Zhang,Meng Zhang,Jun Wang,Lingling Chen,Hongwei Zhang
Pore forming agent or hydrophilic additives are necessary for the optimization of membrane pore structure and surface physicochemical properties. Although it has been demonstrated that the blending additives tends to locate around membrane pore walls due to segregation and this would further leach out in practical operations, the impact of additives fate on membrane pore structure as well as sieving performance is almost overlooked in literatures. In this study, five kinds of Pluronic copolymers with different molecular architectures were employed for casting PSF UF membranes, and the fate of these copolymers in membrane matrix was explored by combing FTIR and XPS spectra with TG analysis . More importantly, the evolutions of membrane mean pore radius (r*) and radius distribution (σ) after additive leaching were quantitatively investigated based on the modified Steric Pore Model (SPM). In passive solute sieving experiments, the increment of r* and σ possessed positive correlation with the degree of polymerization (DP) of EO segments within the corresponding additive. The results of thermoporosimetry and saline filtration experiments further evidenced that such a correlation should be attributed not only to the steric hindrance of EO segment, but also to its hydration ability. Moreover, the intrinsic polymer geometry (r ST ) was also a crucial factor for understanding the evolutions of membrane pore structure during additive leaching. Especially for membranes having small r ST , both the isopropanol (IPA) treatment and poly-dopamine (PDA) decoration experiments suggested that pore enlargement and the generation of new small cavities would occur simultaneously during additive leaching, making the prediction complicated. Finally, we proposed that the relative synthetic aperture (RSA) could serve as a complementary indicator for understanding and describing the pore enlargement behavior of a blended UF membrane. In an industrial point of view, it also offers a new way to evaluate and predict the long-term performance and stability of a blending modified porous membrane.
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