Preparation of hollow carbon-microbeads from water-in-oil emulsion using amphiphilic carbonaceous material

Esumi, Kunio; Eshima, Susumu; Murakami, Yuuji; Honda, Hidemasa; Oda, Hirokazu

doi:10.1016/0927-7757(95)03391-2

Cited by 19 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They are later sacrificed via etching with acid, base or thermal treatment after the carbon shell has been formed [ 7 , 11 , 12 ]. On the other hand, via the soft-templating route, the direct generation of HCSs is achieved through the self-assembly of colloidal systems, such as emulsion droplets, micelles, vesicles, or gas bubbles, originating from carbonaceous precursor molecules, surfactants or additives [ 13 , 14 ]. The soft-templating route is attractive due to the ease of removal of the soft core, however, the morphology, structural properties and mono dispersity of the as-prepared HCSs is more difficult to control.…”

Section: Introductionmentioning

confidence: 99%

Catalyst Design: Counter Anion Effect on Ni Nanocatalysts Anchored on Hollow Carbon Spheres

et al. 2023

View full text Add to dashboard Cite

Herein, the influence of the counter anion on the structural properties of hollow carbon spheres (HCS) support was investigated by varying the nickel metal precursor salts applied. TEM and SEM micrographs revealed the dimensional dependence of the HCS shell on the Ni precursor salt, as evidenced by thick (~42 nm) and thin (~23 nm) shells for the acetate and chloride-based salts, respectively. Importantly, the effect of the precursor salt on the textural properties of the HCS nanosupports (~565 m2/gNi(acet)) and ~607 m2/gNiCl), influenced the growth of the Ni nanoparticles, viz for the acetate-(ca 6.4 nm)- and chloride (ca 12 nm)-based salts, respectively. Further, XRD and PDF analysis showed the dependence of the reduction mechanism relating to nickel and the interaction of the nickel–carbon support on the type of counter anion used. Despite the well-known significance of the counter anion on the size and crystallinity of Ni nanoparticles, little is known about the influence of such counter anions on the physicochemical properties of the carbon support. Through this study, we highlight the importance of the choice of the Ni-salt on the size of Ni in Ni–carbon-based nanocatalysts.

show abstract

Section: Introductionmentioning

confidence: 99%

Catalyst Design: Counter Anion Effect on Ni Nanocatalysts Anchored on Hollow Carbon Spheres

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The raw materials of ACMs are cheap, including mesophase pitch, coal tar pitch, petroleum green coke, green needle coke and so on [2]. Due to their amphiphilic property, ACMs have been used for the preparation of hollow carbon microbeads [3], ultrafine carbon powders [4], amorphous carbon nanoparticles [5], Ti(C, N, O) nanoparticles [6], vesicular carbon with mesopores of 2-4 nm in width [7], mesoporous carbon particles [8] and carbon aerogels [9]. Although most of the mesopores of these porous materials are disordered, it is a simple and inexpensive approach to use ACMs as the precursor of carbon spheres and porous carbons, which have been expected to find extensive applications in catalysis, adsorption and electric conductive materials [8,10].…”

Section: Introductionmentioning

confidence: 99%

Soft-templated Synthesis of Carbon Micron-Buds

Li¹,

Song²,

Li³

et al. 2019

Chem Pharm Res

View full text Add to dashboard Cite

Using coal tar pitch based amphiphilic carbonaceous materials (ACMs) as the precursor and amphiphilic triblock copolymer F127 as the only soft template, hollow Carbon Micro-Buds (CMBs) were synthesized. The concentration of F127, cF, and the mass ratio of F127 to ACM, r, are the key parameters of controlling the shape of the asprepared products. CMBs with diameters of about 1 μm were prepared under the condition of ci = 53.4 g/L and r = 2. CMBs were amorphous materials.

show abstract

Phenolic Resins

Kopf¹

2003

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

Phenolic resins are a family of polymers and oligomers composed of a wide range of structures based on the various reaction products of phenols with formaldehyde. Applications vary from commodity construction materials to high technology applications in electronics and aerospace. Phenolic resins are prepared using acidic or basic catalysts. Weak Lewis acids, such as zinc acetate, are used for specialty resins. Phenolic novolaks are thermoplastic resins prepared from acid catalysts and a molar excess of phenol. They have a molecular weight of 500–5000 and a glass‐transition temperature T g of 45–70°C. Novolak resins are typically cured with 5–15% hexamethylenetetramine as the cross‐linking agent. Resole‐type phenolic resins are produced with a molar ratio of formaldehyde to phenol of 1.2:1 to 3.0:1 and alkaline catalysts such as NaOH, Ca(OH) 2 , and Ba(OH) 2 . A typical resin has an initial molecular weight of 150 to perhaps 1500. For systems of unsubstituted phenols, the final cross‐link density is 150–300 atomic mass units per cross‐link. In 2001, worldwide consumption of phenolic resins exceeded 4 × 10 6 t; slightly less than half of the total volume was produced in the United States, where the largest volume application is in plywood adhesives and accounts for ca 49% of U.S. consumption. As a mature industry, U.S. production of phenolic resins has paralleled the growth in the GNP. Applications for phenolic resins include coatings, adhesives, carbonless copy paper, molding compounds, bonded and coated abrasives, friction materials, foundry resins, laminates, air and oil filters, wood bonding, fiber bonding, composites, spherical fillers, and fibers. Factors contributing to the health and safety concerns of phenolic resins are related primarily to the presence of unreacted phenol and formaldehyde. Unreacted phenol in a resin can range from >10% for liquid resoles used in impregnation processes to <1% for novolaks intended for use as epoxy hardeners. Free formaldehyde can be 2–4% in liquid adhesives.

show abstract

Preparation of hollow carbon-microbeads from water-in-oil emulsion using amphiphilic carbonaceous material

Cited by 19 publications

References 2 publications

Catalyst Design: Counter Anion Effect on Ni Nanocatalysts Anchored on Hollow Carbon Spheres

Catalyst Design: Counter Anion Effect on Ni Nanocatalysts Anchored on Hollow Carbon Spheres

Soft-templated Synthesis of Carbon Micron-Buds

Phenolic Resins

Contact Info

Product

Resources

About