Ion adsorption-induced wetting transition in oil-water-mineral systems

The relative wettability of oil and water on solid surfaces is generally governed by a complex competition of molecular interaction forces acting in such three-phase systems. Herein, we experimentally demonstrate how the adsorption of in nature abundant divalent Ca2+ cations to solid-liquid interfaces induces a macroscopic wetting transition from finite contact angles (≈10°) with to near-zero contact angles without divalent cations. We developed a quantitative model based on DLVO theory to demonstrate that this transition, which is observed on model clay surfaces, mica, but not on silica surfaces nor for monovalent K+ and Na+ cations is driven by charge reversal of the solid-liquid interface. Small amounts of a polar hydrocarbon, stearic acid, added to the ambient decane synergistically enhance the effect and lead to water contact angles up to 70° in the presence of Ca2+. Our results imply that it is the removal of divalent cations that makes reservoir rocks more hydrophilic, suggesting a generalizable strategy to control wettability and an explanation for the success of so-called low salinity water flooding, a recent enhanced oil recovery technology

Ion-Specific and pH-Dependent Hydration of Mica-Electrolyte Interfaces

Hydration forces play a crucial role in a wide range of phenomena in physics, chemistry, and biology. Here, we study the hydration of mica surfaces in contact with various alkali chloride solutions over a wide range of concentrations and pH values. Using atomic force microscopy and molecular dynamics simulations, we demonstrate that hydration forces consist of a superposition of a monotonically decaying and an oscillatory part, each with a unique dependence on the specific type of cation. The monotonic hydration force gradually decreases in strength with decreasing bulk hydration energy, leading to a transition from an overall repulsive (Li+, Na+) to an attractive (Rb+, Cs+) force. The oscillatory part, in contrast, displays a binary character, being hardly affected by the presence of strongly hydrated cations (Li+, Na+), but it becomes completely suppressed in the presence of weakly hydrated cations (Rb+, Cs+), in agreement with a less pronounced water structure in simulations. For both aspects, K+ plays an intermediate role, and decreasing pH follows the trend of increasing Rb+ and Cs+ concentrations

Salinity-Dependent Contact Angle Alteration in Oil/Brine/Silicate Systems: the Critical Role of Divalent Cations

The effectiveness of water flooding oil recovery depends to an important extent on the competitive wetting of oil and water on the solid rock matrix. Here, we use macroscopic contact angle goniometry in highly idealized model systems to evaluate how brine salinity affects the balance of wetting forces and to infer the microscopic origin of the resultant contact angle alteration. We focus, in particular, on two competing mechanisms debated in the literature, namely, double-layer expansion and divalent cation bridging. Our experiments involve aqueous droplets with a variable content of chloride salts of Na+, K+, Ca2+, and Mg2+, wetting surfaces of muscovite and amorphous silica, and an environment of ambient decane containing small amounts of fatty acids to represent polar oil components. By diluting the salt content in various manners, we demonstrate that the water contact angle on muscovite, not on silica, decreases by up to 25° as the divalent cation concentration is reduced from typical concentrations in seawater to zero. Decreasing the ionic strength at a constant divalent ion concentration, however, has a negligible effect on the contact angle. We discuss the consequences for the interpretation of core flooding experiments and the identification of a microscopic mechanism of low salinity water flooding, an increasingly popular, inexpensive, and environment-friendly technique for enhanced oil recovery

Probing the Surface Charge on the Basal Planes of Kaolinite Particles with High-Resolution Atomic Force Microscopy

High-resolution atomic force microscopy is used to map the surface charge on the basal planes of kaolinite nanoparticles in an ambient solution of variable pH and NaCl or CaCl₂ concentration. Using DLVO theory with charge regulation, we determine from the measured force–distance curves the surface charge distribution on both the silica-like and the gibbsite-like basal plane of the kaolinite particles. We observe that both basal planes do carry charge that varies with pH and salt concentration. The silica facet was found to be negatively charged at pH 4 and above, whereas the gibbsite facet is positively charged at pH below 7 and negatively charged at pH above 7. Investigations in CaCl₂ at pH 6 show that the surface charge on the gibbsite facet increases for concentration up to 10 mM CaCl₂ and starts to decrease upon further increasing the salt concentration to 50 mM. The increase of surface charge at low concentration is explained by Ca²⁺ ion adsorption, while Cl^– adsorption at higher CaCl₂ concentrations partially neutralizes the surface charge. Atomic resolution imaging and density functional theory calculations corroborate these observations. They show that hydrated Ca²⁺ ions can spontaneously adsorb on the gibbsite facet of the kaolinite particle and form ordered surface structures, while at higher concentrations Cl^– ions will co-adsorb, thereby changing the observed ordered surface structure

Competitive Strategies of the Lithium Battery Industry in Taiwan:A Case Study

Lithium batteries possess advantages over other batteries in terms of safety, life, amplification of electricity, and environmental protection. Numerous countries have put substantial efforts on developing the technique of the lithium battery. In addition to 3Cs' products (i.e., computer, communications, and consumer electronics), lithium batteries are gradually applied to hand tools, wheelchairs, golf cars, bicycles, motorcycles, automobiles, and energy saving systems. The battery industry seems to have significant breakthrough in the near future. LFP (LiFePO4) batteries emerge due to technical innovations, relative costs, and new demand. However, the defects of emerging industries include lack of solid competitive foundation, vague game rules, small size, and immature technology. Under uncertainty, the LFP industry contains high risk as well as many opportunities. Confronted with competition from international companies, small-medium companies of Taiwan need to use valid competitive strategies to survive. This study attempts to provide clinical profiles and find out useful strategies for a battery company of Taiwan. The analytical results provide insights to industry practitioners and references to future related studies.鋰鐵電池具備安全性、壽命長、可大電流充放電、環保等性能，明顯優於其他電池，為世界各國正積極開發之電池技術，電池除廣泛應用於三C 產品外，因高功率電池之開發，逐漸擴大應用至手動工具、醫療輪椅、高爾夫球車、自行車、機車、汽車等，甚至太陽能電池、家用儲能等，多年來未有顯著突破的電池產業，在未來幾年將出現革命性發展！鋰鐵電池因技術創新、相對成本關係轉變、消費出現新需求，而轉型成為新興產業。新興產業的基本特色就是缺乏穩固的競爭基礎、缺乏其他遊戲規則、發展初期規模太小、技術太新，在充滿不確定性的情形下，既是風險也是機會。 面對國際級競爭廠商，台灣中小型企業如何運用競爭策略，是組織學習成長及永續經營的關鍵因素。是故擬對國內鋰電池產業的發展現況作進一步的瞭解與剖析，並以個案公司的角度，找出鋰鐵電池產業的未來較佳的經營策略，研究結果可供相關產業制訂競爭策略上的參考，並進一步探討其管理上的策略涵義，亦可作後續研究鋰鐵電池產業發展的參考依據。目 次 第一章 緒論 1 第一節 研究動機 1 第二節 研究目的 2 第二章 文獻探討 3 第一節 策略管理的相關文獻 3 第二節 鋰電池產業發展的相關文獻 5 第三章 研究方法 9 第一節 研究設計及架構 9 第二節 資料來源 10 第四章 鋰電池產業分析 12 第一節 電池產業 12 第二節 二次電池市場 14 第三節 鋰電池市場 17 第四節 鋰鐵電池市場 22 第五章 個案分析 29 第一節 個案公司簡介 29 第二節 同業競爭者分析 29 第三節 個案公司SWOT分析 37 第四節 個案公司競爭策略 39 第五節 個案公司展望 44 第六章 結論及建議 48 第一節 結論 48 第二節 建議 49 參考文獻 51 中文部份 51 英文部份 52 網站部份 52 表目次 表2- 1 三種一般競爭策略之內涵 5 表4- 1 一次電池特性比較表 12 表4- 2 二次電池特性比較表 13 表4- 3 各種鋰電池特性比較 18 表4- 4 台灣NB模組市佔率 20 表4- 5 各類動力電池比較 22 表4- 6 全球HEV預估數量 25 表4- 7 全球EBIKE出貨量 25 表4- 8 全球電動代步車及電動輪椅車市場需求量 26 表4- 9 中國LED路燈市場規模 28 表5- 1 鋰鐵材料主要競爭者分析 30 表5- 2 SWOT分析 38 表5- 3 個案公司的經營策略建議 45 圖目次 圖2- 1 供應鏈波特五力模型架構圖 3 圖2- 2 PORTER之一般性策略 4 圖3- 1 研究流程圖 10 圖4- 1 電池簡介 12 圖4- 2 全球二次電池市場規模 14 圖4- 3 全球小型二次電池市場規模 15 圖4- 4 全球小型二次電池應用領域 15 圖4- 5 全球小型二次電池主要生產國 16 圖4- 6 電池種類與能量密度/起始電壓比較 16 圖4- 7 二次電池發展趨勢 17 圖4- 8 鋰電池產業關聯圖 17 圖4- 9 NB／PC成本分析 18 圖4- 10 鋰電池銷售量圖 19 圖4- 11 全世界HEV混成電動車的生產量預測圖 21 圖4- 12 鋰鐵電池適用產品種類圖 24 圖4- 13 全世界HEV市場電池產值 25 圖4- 14 全球EBIKE市場電池產值 26 圖4- 15 全球電動代步車及電動輪椅車市場電池產值 26 圖4- 16 電動手工具機市場 27 圖4- 17 中國太陽能LED路燈市場電池產值 28 圖4- 18 鋰鐵電池潛在市場商機 28 圖5- 1 鋰鐵電池產業五力分析圖 36 圖5- 2 個案公司競爭策略及累積超額報酬率（未扣除大盤） 42 圖5- 3 個案公司競爭策略及累積超額報酬率（已扣除大盤） 4

Spontaneous Structuration of Hydrophobic Polymer Surfaces in Contact with Salt Solutions

It has been described in previous chapters how spontaneous instabilities related to interfacial phenomena can be used to produce controlled patterns on polymer surfaces. Strategies of polymer patterning assisted by dewetting or water drop condensation were described. In this chapter we present a waterborne process based on the interaction between ions in water and hydrophobic polymer surfaces, modulated by the gases dissolved in the aqueous phase. We show how by controlling this interaction the polymer surface can be conveniently modified. In the first section of the chapter we describe some aspects of the interface between water and a hydrophobic surface. We then describe how the composition of the aqueous phase can have important consequences on the morphology of the hydrophobic surface, and then illustrate how this process can be conveniently used to modify the morphology of a hydrophobic polymer in a controlled manner