The mechanical strength of hydrogels and cryogels made from carboxylated nanocellulose (NC) fibers can be modulated by chemically/physically crosslinking and blending with different fibrils (shorter/longer). Nanocellulose hydrogels are produced by oxidizing Bleached Eucalyptus Kraft (BEK) pulp followed by high pressure mechanical treatment. Polyethyleneimine (PEI) and hexamethylenediamine (HMDA) were selected to crosslink nanocellulose hydrogels physically and chemically, respectively. Shorter cellulose nanocrystals (CNC) and longer microcrystalline cellulose (MCC) fibrils were blended with the TEMPO oxidized nano/micro fibers to produce hydrogels of controlled properties. Nanocellulose cryogels were prepared from these hydrogels by a two steps process of freezing and lyophilization. The mechanical properties of nanocellulose hydrogels and cryogels were modulated by controlling the type and density of crosslinking as well as by blending with nano- or microfibrils. Chemical crosslinking (HMDA) increases the hydrogel elastic compression moduli (G′) but does not significantly affect the compressive strength of the cryogel. SAXS reveals the HMDA crosslinked hydrogel to be structurally homogeneous. Physical crosslinking with high molecular weight PEI increases the storage modulus (G′) of nanocellulose hydrogels. Blending a carboxylated nanocellulose fiber suspension with CNC significantly increases the cryogel compressive strength. Nanocellulose gel exhibits tuneable mechanical strength and absorption capacity from the crosslinking/blending strategy (type and density); this improved fundamental knowledge of the fiber-crosslinker and fiber-cellulose crystal interactions enables greater control and tunability of the properties of hydro- and cryogels for personal and infant care products, as agricultural water retention aids, and for biosensor applications.

由羧化纳米纤维素 (NC) 纤维制成的水凝胶和冷冻凝胶的机械强度可以通过化学/物理交联和与不同原纤维（较短/较长）混合来调节。纳米纤维素水凝胶是通过氧化漂白桉树硫酸盐 (BEK) 纸浆，然后进行高压机械处理来生产的。选择聚乙烯亚胺 (PEI) 和六亚甲基二胺 (HMDA) 分别以物理和化学方式交联纳米纤维素水凝胶。较短的纤维素纳米晶体 (CNC) 和较长的微晶纤维素 (MCC) 原纤维与 TEMPO 氧化的纳米/微纤维混合，以生产具有受控特性的水凝胶。通过冷冻和冻干两步过程，从这些水凝胶制备纳米​​纤维素冷冻凝胶。纳米纤维素水凝胶和冷冻凝胶的机械性能通过控制交联的类型和密度以及与纳米或微纤维混合来调节。化学交联 (HMDA) 增加了水凝胶弹性压缩模量 (G')，但不会显着影响冷冻凝胶的压缩强度。SAXS 表明 HMDA 交联水凝胶在结构上是均匀的。与高分子量 PEI 的物理交联增加了纳米纤维素水凝胶的储能模量 (G')。将羧化纳米纤维素纤维悬浮液与 CNC 混合可显着提高冷冻凝胶的抗压强度。纳米纤维素凝胶通过交联/混合策略（类型和密度）表现出可调节的机械强度和吸收能力；